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Recently in the Flowers Category

Shake Rattle & Role: BUZZ Pollination

Karl Foord, Extension Educator - Horticulture

I recently had the rare priviledge of traveling to Tucson, Arizona to visit the laboratory of Dr. Dan Papaj. I worked with Dr. Stephen Buchmann (author of several fine books) and Avery Russell to photograph buzz pollination of Solanum species flowers by the Common Eastern Bumble Bee (Bombus impatiens).

Buzz pollination occurs when an insect visiting a flower uses vibration to extract pollen from the anthers of a flower. This is accomplished by the insect activating their wing muscles without flying. This vibration shakes the anthers of the flower causing pollen to pore out the end of the anther; anthers having pores at their end are called porical for this reason.

This is not an isolated occurance as some 15,000 to 20,000 plant species have pores or slits at the end of their anthers. Also some 50 genera of bees possess the capability to accomplish buzz pollination. Interestingly enough, honey bees are not capable of buzz pollination.

Poricidal anthers are often found on flowers that also lack nectaries, and flowers that have developed anthers of different lengths facilitating pollen dispersal on the pollinating insect.

Middle C on the piano is 262 Hz (beats per second) and A above middle C is 440 Hz (the tone orchestras use to tune their instruments). The peak frequency used in buzz pollination is in between these two frequencies at 330 Hz. Buzz pollination also produces lesser peaks at the five harmonic frequencies above 330 e.g. 660, 990, 1320, and 1650.

I have produced a video of buzz pollination filmed with a high speed camera that allows one to actually see the shaking of the bee. Under normal circumstances this would only be visible as a blur. The bees were filmed at 1,000 frames per second meaning that they have been slowed down by a factor of 33.3.

Please enjoy the video!

Hollyhock Rust at its Worst

M. Grabowski, UMN Extension

Photo 1: Hollyhock rust on leaves

Michelle Grabowski, UMN Extension Educator


Frequent rains this spring and early summer have created favorable conditions for hollyhock rust. Hollyhock rust is caused by the fungal pathogen Puccinia malvacearum, which infects hollyhocks and related weeds like roundleaf mallow (Malva neglecta).

Early symptoms of hollyhock rust are easily missed. Small waxy yellow bumps form on the lower surface of the lower leaves of the plant. With age, these pustules turn reddish brown and a bright orange spot develops on the upper leaf surface. In wet years, spores from these early infections easily spread to infect leaves, stems, petioles and even flower bracts. Heavily infected leaves turn yellow and may wither and curl. This significantly reduces the plant's ability to do photosynthesis. The hollyhock rust fungi can survive from one season to the next in infected live crowns, as spores in infected plant debris, or on seed from infected plants.

M. Grabowski, UMN Extension

Photo 2: Hollyhock rust on stem and flower bracts

Unfortunately it is too late to prevent hollyhock rust this season. Keep plants as dry as possible by avoiding sprinkler irrigation and pulling weeds to improve air circulation around the plants. This will help to reduce spread of existing infections. Gardeners with infected plants should cut off the plant at ground level after flowering is complete. Infected plant material should be removed from the garden and buried, placed in a compost pile that heats up or taken to a municipal compost facility. Next year, mulch around the base of the plant to reduce the spread of spores from plant debris. Scout plants in early spring. Look for yellow waxy pustules on the lower leaf surface. Infected leaves should be removed and buried or composted.

The following list is updated with links to new and revised online Extension publications as they become available. 

June 17, 2014

General/Curiosity Insects (NEW!)
A new addition to the Extension Y&G diagnostic tool "What insect is this?" Find information to help identify and understand insects (1) with obvious wings (flies, wasps, moths, etc.) and (2) insects without obvious wings (beetles, bugs, ants etc.).


May 27, 2014

Carpenter ants (revised)
Bronze birch borer and twolined chestnut borer in Minnesota (revised)
Maple petiole borer
(revised)
Nightcrawlers (revised) 

December 2, 2013

Pest management in the home strawberry patch (new)
Pest management for home blueberry plants (new)
Integrated pest management for home raspberry growers (new)
Integrated pest management for home stone fruit growers
(new)
Leafminers in home vegetable gardens
(new)


August 26, 2013

Masked hunters (revised)
Fourlined plant bug in home gardens (revised)


July 16, 2013

"Annuals" have been added to What's wrong with my plant? diagnostic tool.

June 18, 2013

Root maggots in home gardens (new)
Emerald ash borer in Minnesota (revised)
The Extension EAB web page has also been revised

May 23, 2013

Anthracnose (revised)
Powdery Mildew
(revised)
Cedar Apple Rust and Other Gymnosporangium Rusts
(revised)
Crown Gall (revised)

Managing Apple Scab on Ornamental Trees and Shrubs
(revised)
Managing Impatiens Downy Mildew in the Landscape (new)

Managing Impatiens Downy Mildew in Greenhouses, Nurseries, and Garden Centers
(new)
Basil Downy Mildew
(new)

May 1, 2013

Aphids on Minnesota Trees and Shrubs (revised)
Woolly Aphids on Minnesota Trees and Shrubs (revised)
Spotted Wing Drosophila (new)
Two-spotted Spider Mites in the Home Garden and Landscape (new)

Karl Foord, Extension Educator - Horticulture

Karl Foord

Photo 1: Andrenid Bee on Willow Flower




Karl Foord


Photo 2: Andrenid Bee on Prunus flower





Karl Foord


Photo 3: Andrenid Bee on apple flower





Karl Foord


Photo 4: Andrenid Bee and blueberry flowers


Karl Foord

Photo 5: Andrenid bees on raspberry flowers


Andrenid bees are one of the earliest emerging bees in the spring. You can see them on willow flowers depending on the type of spring (Photo 1), and we had such a spring this year. Following willows the Andrenids will often be found on Prunus species (plums & cherries) (Photo 2). The next trees and shrubs to flower are apples (Photo 3), blueberries (Photo 4), and raspberries (Photo 5). Andrenid bees are important native pollinators of these species. The next time you put blueberries on your breakfast cereal or make raspberry jam, remember that Andrenid bees have played a significant role in the creation of those fruits.

Karl Foord, Extension Educator - Horticulture




Karl Foord


Photo 1: Honey bee on dandelion


Karl Foord

Photo 2: Honey bee on Dandelion

Karl Foord

Photo 3: Split and curled stigmas of dandelion

Karl Foord

Photo 4: Dandelion stigmas & honey bee corbicula




Karl Foord


Photo 5: Native Mining bee (Andrena spp.)





Karl Foord


Photo 6: putative - Plasterer Bee (Colletes spp.)


Karl Foord

Photo 7: Native Small Carpenter Bee (Male) (Ceratina spp.)

For years I used to fight the dandelions in my lawn. I used herbicides and a small trowel. It was a bit of a losing battle as there is a third of an acre of school property adjacent to mine where dandelions are not controlled. This being separate from the nearby sports fields where the weeds are controlled. Imagine the number of dandelion seeds that blew into my yard each year.

As I have become more aware of pollinators, I have come to accept and perhaps even embrace the "noble" dandelion. Dandelions are an important source of pollen and nectar for bees early in the season when little else is flowering.

Given the problems facing our honey bees and native bees, it might be worth reconsidering dandelions and what they contribute to pollinator health. So with my new attitude I took camera in hand and ventured into the dandelion patch (Photo 1).

Consider how artistic is the dandelion flower when viewed close-up (Photo 2). The flowers each have split lobed stigmas that curl back and sometimes twist into shapes similar to the letter F shape holes cut into violins (Photo 3). Consider also the beautiful orange color of the dandelion pollen as attached to the corbicula or pollen basket of the honey bees (Photo 4).

The dandelion also provides nectar and pollen for our native bees: Mining Bees (Andrena spp.) (Photo 5), Plasterer Bees (Colletes spp.) (Photo 6), and Small Carpenter Bees (Ceratina spp.) (Photo 7). If you use your lawn for recreation and need a dense turf as a playing surface, you may want to control dandelions. However if this is not the way you use your turf, please consider letting some of the dandelions provide forage for our pollinators. In this way you can be a part of the solution to the ills facing our pollinators.

Karl Foord, Extension Educator - Horticulture

Karl Foord

Exhibit 1: Cucumber flowers

aggie-horticulture.tamu.edu/galveston

Exhibit 2: Cucumber flowers

www.uq.edu.au

Exhibit 3: Male squash bees in squash flower




www.uq.edu.au


Exhibit 4: Male squash bees in squash flower


The plant family Cucurbitaceae contains a number of our favorite garden plants. This includes: cucumbers, watermelon, muskmelon, pumpkins, squash, and gourds. This group is particularly fascinating in terms of its flower morphology. These plants are called monoecious because they have separate male and female flowers on the same plant (Exhibit 1). These flowers are most easily recognized by the shape of the stem below the flower. The stem below the female flower looks like a smaller version of the final fruit (Exhibit 2), and the stem below the male flower remains a single slender stalk.

Cucurbit flowers are short lived flowers that open a few hours after sunrise and are often closed by midday or early afternoon. Both male pollen viability and female stigmatic receptivity are at their highest when the flower opens and for the next few hours. Both pollen viability and stigmatic receptivity decrease significantly as the day progresses. It is important for the female flower to be pollinated as early in the day as possible.

In cucurbits there is one key concept: The quality of the fruit is a function of the number of seeds in the fruit. The number of seeds produced is a function of the number of viable pollen grains deposited on the stigma. The number of pollen grains deposited is a function of the number of visits by pollinators as well as by the type of bee visiting the flower. Expressed as an equation:

Quality of Fruit ~ # of seeds ~ pollen grains deposited ~ # of bee visits & type of bee

Because both male and female sexual parts are not in the same flower, pollen must be transferred from the male flower to the female flower. The pollen is too large and sticky to be transferred by wind and thus requires insect transfer. Bumble bees tend to deposit more pollen per visit than squash bees and squash bees tend to deposit more pollen per visit than honey bees.

To produce quality fruit watermelon need on the average 1,000 grains of pollen deposited, whereas pumpkin, cucumber and cantaloupe need between 300 and 400.

These flowers need to be visited multiple times (@ 10 - 12) by pollinators to achieve satisfactory pollen transfer and seed set.

Like the solanaceous crops in the previous article, these plants prefer higher temperatures and are sensitive to frost. Daytime temperatures in the high 70s or low 80s degrees and nighttime temperatures close to 65 degrees are optimum for seed set and growth. Poor fruit set or misshapen fruit can sometimes be the result of poor weather which has limited pollinator activity leading to poor pollination and insufficient seed set.

Another very interesting thing about squash flowers is that there is a bee that has evolved as a pollinator specific to squash flowers. Surprisingly enough this bee has been named a Squash Bee (Peponapis pruinosa). Another fun thing is that the male squash bees will often spend the night and parts of the day in the protected space created by the squash flower petals (Exhibits 3 & 4). So if you choose to grow squash you get the potential added treat of watching these very interesting bees.

In addition squash bees are solitary ground nesting bees who will often dig their ground nests in the garden near the squash plants. If you find holes in your garden that are a half inch in diameter, it could be the entrance to the squash bees nest. The linked article in the above paragraph has a picture of the entrance to a squash bee nest. If you encounter such a nest in your garden, one option would be to avoid tilling around this nest and encourage next year's squash bees. If you continue to plant squash every year you could end up with permanent residents.

Karl Foord, Extension Educator - Horticulture

www.uq.edu.au

Figure 1: Tomato flower

Insect Pollination of Cultivated Crop Plants, S.E. McGregor, 1976

Figure 2: Tomato flower structure

pollinator.info

Photo 1: Bumble bee on tomato flower

Temperature Sensitivity of Flowers

Tomatoes are heat loving plants that require a long frost-free season and full sun. The flowers have optimal temperature ranges and are sensitive to extremes. The flowers will abort and drop from the plant when extremes are experienced. In early spring when night temperatures drop below 55 degrees F, the blossoms can drop. In summer when daytime temperatures exceed 90 degrees F or when nighttime temperatures remain above 75 degrees F, the flowers can abort. In addition drought stress can also cause flower abortion.

The Tomato Flower

The tomato flower is hermaphroditic containing both male and female organs (Figure 1). The flower is self-fertile but not self-pollinating. The tomato anthers fuse to form a tube that surrounds the style. Pollen is released from pores located on the inside of the tube as shown in Figure 2. The flower requires vibration to shake the pollen grains from the anther pores to the stigmatic surface.

Sufficient pollen movement to achieve maximum fruit set is usually achieved when plants are grown outside and subject to vibration by wind. One reason this works is because the stigma is receptive for a relatively long period of time e.g. from 1-2 days before anther dehiscence to 4-8 days after dehiscence.

Pollinators

Plants grown in glasshouses do not receive enough vibration and are usually pollinated by purchased bumble bees. Bumble bees effect "buzz" pollination by vibrating their flight muscles without moving their wings (Photo 1). This serves to shake the pollen from the anthers where it falls on the stigmatic surface and the body of the bee.

Honeybees will not visit tomato flowers because the flowers have no nectaries and the structure of the flower makes access to pollen difficult.

Recommendations

Find ways to protect your tomato plants from low temperatures in early spring with either water jackets of various types, or row covers to hold ground heat around the plant.

Black Leg of Geranium

M. Grabowski, UMN Extension Educator

M. Grabowski

Photo 1: Black leg of Geranium caused by Pythium spp.

Black leg is a stem infection of Geraniums (Pelargonium spp.) that results in a distinctive black discoloration of stems. As infected stems rot, they become soft and often bend over. This disease is caused by several species of the water mold Pythium. Pythium spp. are soil dwelling organisms that thrive in wet conditions and can survive in infected plant debris and soil. Black leg symptoms often start at the soil line and move up the plant.

To avoid black leg, inspect all geraniums prior to purchase and select only healthy symptom free plants. If repotting geraniums, use new clean potting mix and new pots or pots that have been cleaned with a solution of 10% household bleach. Take care to keep tools, watering cans, and hose heads off the floor and away from dirt and plant debris. Pythium spp. can be introduced into clean potted plants by tools that have contacted contaminated dirt or plant debris. Do not over water plants.

If plants do become infected, they will not recover. Discard the plant and the potting mix. Clean the pot with a solution of 10% household bleach before reusing it.

Favorite plants for Valentine's Day

What is Valentine's Day without expounding on some favorite, romantic plants? Roses are the traditional flower to give on this day of lovers, but as many of my gardening cohorts know, orchids are one of my favorite types of plant life.

According to Orchids of Minnesota by Welby Smith, estimates note upwards to 23,000 P1210761.JPGspecies of orchids in the world (7-10% of flowering plants). In Minnesota, we have 42 wild orchids that migrated here - a surprise as we think of orchids as fragile plants and tropical. But think of our state flower - the showy lady's slipper (Cypripedium reginae) - it is an orchid and grows in ditches along our roads! These are some tough organisms - and I find them a real pleasure to grow. Today it's easy and inexpensive to buy orchids - especially moth orchids (Phaleanopsis or "phals" ). I admit to buying one of my most reliable phals at IKEA! (it was my first and pictured here in full bloom).

I have found the limitations for growing orchids as houseplants similar to other houseplants: light, water, and patience - especially true in the case of orchids. Growers also need to appreciate the whole plant - not just the blossoms - as healthy leaves and firm, strong roots mean flowers are in the future. Most orchids perform best in a bright window in the winter months and filtered sun in the summer. Moth orchids are more tolerant of lower light situations indoors (another good reason for trying one). Keep leaves clear of dust too using a soft damp cloth.

Let your orchid dry out between watering and use rainwater, melted snow, or RO water (reverse osmosis and refillable at many grocery stores). Don't use tap water as it is usually softened and treated. Add a dilute amount of orchid fertilizer each time you water and flush plants once a month with clear water to eliminate salts that have collected. Note that plants growing in sphagnum moss will hold salts in the moss, soorchid6.JPG fertilize less often. Once a plant has finished flowering, leave the flower stem on the plant till it turns brown as sometimes they re-bud. After blooming, the leaves may appear wilted and dull, but continue good care and they will return to their thick, green condition. Celebrate new leaves and the crazy silvery roots as they indicate a a healthy plant and more flowers to come.

Take a look at our publication Phalaenopsis and Paphiopedilum species: Easy orchids to grow as houseplants. A great field trip for any orchid enthusiast - beginner or expert - is to the Como Park Conservatory, the conservatory at the U of MN Landscape Arboretum or, if you need a greenhouse shopping experience (as I recently did on a -20 degree day), visit Orchids Limited in Plymouth MN.

Recently, a new Extension Master Gardener intern told how orchids grew everywhere in her homeland. All I could do was sigh.... Enjoy these pics and happy Valentine's Day!


In a followup to Part I on Impatiens Downy Mildew, Extension Educator Michelle Grabowski discusses management of the disease.




Michelle Grabowski


Photo 1: Sporangia of the pathogen Plasmopara obducens that causes impatiens downy mildew


Impatiens Downy Mildew Part II: Management

In this highly informative video, Extension Educator Michelle Grabowski explains the symptoms of this disease and how to identify it.




Michelle Grabowski


Photo 1: Early stages of the disease Impatiens Downy Mildew (Plasmopara obducens)





Michelle Grabowski


Photo 2: Sporangia of Plasmopara obducens found on the underside of the leaf of an impatiens plant carrying the disease Impatiens Downy Mildew



Impatiens Downy Mildew

Plant Video Library 2014 cont.

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture




Karl Foord


Photo 2: Purple Coneflower (Echinacea purpurea) on left and Pale Purple Coneflower (Echinacea pallida on right


Karl Foord

Photo 3: Trumpet Vine (Campsis radicans




Karl Foord


Photo 4: Mexican Sunflower (Tithonia rotundifolia





Karl Foord


Photo 5: Bugbane (Actaea racemosa


Karl Foord

Photo 6: Nodding Wild Onion (Allium cernuum




Karl Foord


Photo 7: Great Blue Lobelia (Lobelia siphilitica





Karl Foord


Photo 8: Flowering Spurge (Euphorbia corollata





Karl Foord


Photo 9: Allegheny Spurge (Pachysandra procumbens


Pale Purple Coneflower

Trumpet Vine

Mexican Sunflower

Bugbane or Black Snakeroot

Nodding Wild Onion

Great Blue Lobelia

Flowering Spurge

Pachysandra procumbens

Plant Video Library 2014

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture




Karl Foord


Photo 1: Royal Catchfly(Silene regia


Karl Foord

Photo 2: Wild Petunia (Ruella humilis




Karl Foord


Photo 3: Wild Bergamot(Monarda fistulosa


Karl Foord

Photo 4: Tall Boneset (Eupatorium altissimum

Karl Foord

Photo 5: Jewelweed (Impatiens capensis


Royal Catchfly (Silene regia)

Wild Petunia (Ruella humilis)

Wild Bergamot (Monarda fistulosa)

Tall Boneset Revised

Jewelweed Revised

Rust fungi infect fall blooming perennials

M. Grabowski, UMN Extension

Photo 1: Asters showing lower leaf death from rust infection

M.Grabowski, UMN Extension Educator


As the summer winds down, Minnesota gardeners look to fall blooming asters like goldenrod and New England aster to bring color to the garden. In addition to colorful blossoms, less desirable colorful rust fungi can commonly be found infecting the leaves of these perennials. Many gardeners first notice rust infection when the lower leaves of an aster plant turn brown and die. In severe cases, over 50% of the leaves can be killed, often from the bottom up. Upon closer examination, a gardener will notice bright orange or chocolate brown bumps on the lower surface of green leaves and along green stems. These rust pustules are filled with hundreds of fungal spores.




M. Grabowski, UMN Extension


Photo 2: Coleosporium asterum on aster



There are several different rust fungi that infect asters in Minnesota. Infection by Coleosporium asterum results in yellow leaf spots on the upper leaf surface and raised orange spore filled pustules on the lower leaf surface of New England aster and golden rod. Like many rust fungi, C. asterum needs two different host plants to complete it's life cycle. In addition to infecting asters, C. asterum also infects the needles of red, Scots and jack pines. Infected pine needles have small white column-like spore producing structures that release powdery orange spores in early summer. These spores are carried by wind and infect near by asters. Spores produced within aster leaf spots throughout the summer reinfect the aster plant and any nearby asters. In fall, however a different spore type is formed on the aster that is carried by wind to infect nearby pine trees.

M. Grabowski, UMN Extension

Photo 3: Puccinia sp. on aster

Aster plants with chocolate brown pustules on the lower leaf surface are infected by Puccinia asteris, Puccinia campanulae, or other species of Puccinia. The Puccinia rust fungi infect aster as well as several grasses and sedges. They do not infect pine trees.


If leaf death is not severe, rust can be tolerated on asters. Infection by rust fungi often results in little to no affect on plant growth or blossom production. To reduce the severity of the disease, gardeners should take steps to reduce moisture on the foliage. Dense beds should be thinned and overgrown plants divided. Water with drip irrigation or use sprinklers early on a sunny day so that leaves dry quickly. Mulch the soil with woods chips or other organic matter to keep soil moisture from evaporating and increasing humidity in the plant canopy. Plants with a history of infection can be scouted regularly throughout the summer. As rust infection develops on a few leaves, theses leaves can be pinched off and buried to reduce spread of the pathogen.

Flower Video Library for 2013 Sun Plants IV

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture




Karl Foord


Photo 1: Golden Showers Coreopsis (Coreopsis verticillata 'Golden Showers')


Karl Foord

Photo 2: Prickly Pear Cactus (Opuntia humifusa)

Karl Foord

Photo 3: Brown-eyed Susan (Rudbeckia triloba)


Bush Honeysuckle (Diervilla)

Golden Showers Coreopsis (Coreopsis verticillata 'Golden Showers')

Prickly Pear Cactus (Opuntia humifusa)

Brown-eyed Susan (Rudbeckia triloba)

Purple Coneflower with Aster Yellows

Ground Clematis (Clematis recta)

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture




Karl Foord


Photo 1: Vine Honeysuckle (Lonicera tellmanniana)


Karl Foord

Photo 2: Spiderwort (Tradescantia virginiana)

Karl Foord

Photo 3: Pale Coneflower (Echinacea pallida)




Karl Foord


Photo 4: Little Titch Catmint (Nepeta racemosa 'Little Titch')





Karl Foord


Photo 5: Creeping Phlox (Phlox subulata)


Vine Honeysuckle (Lonicera tellmanniana)

Spiderwort (Tradescantia virginiana)

Pale Coneflower (Echinacea pallida)


Little Titch Catmint (Nepeta racemosa 'Little Titch')

Clustered Bellflower (Campanula glomerata 'Joan Elliot')

Dianthus Firewitch (Dianthus gratianopolitanus 'Firewitch')

Creeping Phlox (Phlox subulata)

Aster Yellows in 2013

Michelle Grabowski, UMN Extension

M.Grabowski, UMN Extension

Photo 1: Purple cone flowers infected with aster yellows

Many gardeners had never heard of the plant disease called aster yellows before 2012. As summer progressed, however, flowers on purple cone flowers open up to green spikey alien like blossoms, carrots were thin, hairy and bitter when dug up and plants from onions through tomatoes turned a sickly shade of yellow. The plant disease aster yellows was responsible for all of this.


Aster yellows is caused by a phytoplasma, a small bacteria that lives only within the vascular system of a plant or within the aster leafhopper that carries it from plant to plant. Once a plant is infected, the aster yellows phytoplasma moves systemically through the plant, infecting every part from the roots through the flowers. Symptoms of the disease include yellowing of leaves and stems, unusual flower formation and clusters of weak stems known as witches brooms. The aster yellows phytoplasma can infect over 350 plants including many common vegetables, flowers and weeds. Once a plant is infect, it can never be cured.

M.Grabowski, UMN Extension

Photo 2: Petunias with yellow leaves and small discolored flowers from aster yellows

In 2012, unusually high numbers of aster leafhoppers migrated into Minnesota from southern states where they overwinter. Many of these leafhoppers were carrying the AY phytoplasma. As a result exceptionally high rates of aster yellows was seen throughout Minnesota.


So what is the status of aster yellows in Minnesota in 2013. Happily there have been significantly fewer reports of disease throughout Minnesota in 2013. This is likely due to a combination of factors. Aster yellows can survive Minnesota's winter in perennial plant parts like the crown of an infected purple cone flower. Gardeners that did not remove infected perennials last year may see symptoms again this year. The aster yellows phytoplasma that infected any annual plant like a tomato or cosmos, however, would have died with the plant at the first hard frost. Very few aster leaf hoppers overwinter in Minnesota as eggs and these do not carry the aster yellows phytoplasma. In addition, surveys indicate that lower than average numbers of aster leafhoppers migrated into Minnesota in 2013. Gardeners should continue to watch for symptoms of aster yellows and remove any infected plants.

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Karl Foord

Photo 1: Garden Glow Dogwood (Cornus hessei 'Garden Glow')


Garden Glow Dogwood




Karl Foord


Photo 2: Bracken Fern (Pteridium aquilinum)



Bracken Fern




Karl Foord


Photo 3: Lady's Mantle (Alchemilla mollis)



Lady's Mantle




Karl Foord


Photo 4: Hosta 'Glory'


Hosta 'Glory'

Karl Foord

Photo 5: Bugbane, Black Snakeroot (Actaea racemosa)


Bugbane

Karl Foord

Photo 6: Purple Fringed Loosestrife Lysimachia ciliata

Purple Fringed Loosestrife

Editors note: These videos were filmed in 2012

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Karl Foord

Photo 1: Russian Sage (Perovskia atriplicifolia)

Russian Sage

Karl Foord

Photo 2: Ingwersen's Variety Geranium (Geranium macrorrhizum 'Ingwersen's Variety')

Ingwersen's Variety Geranium

Karl Foord

Photo 3: Adam's needle (Yucca filamentosa)


Adam's Needle (Yucca filamentosa)




Karl Foord


Photo 4: Giant Fleece Flower (Persicaria polymorpha)



Giant Fleece Flower

Karl Foord

Photo 5: Rosa 'Summer Waltz')

Rosa 'Summer Waltz'

Giant Onion Rose Mallow Combination




Karl Foord


Photo 6: Rose Mallow (Hibiscus 'Blue River II')



Harebell Campanula

Karl Foord

Photo 7: Harebell Campanula (Campanula rotundifolia)

Editors note: These videos were filmed in 2012

Karl Foord - Extension Educator, Horticulture

Karl Foord

Photo 1: Flower garden for pollinators

Karl Foord

Photo 2: Great black wasp (Sphex pensylvanicus)

Karl Foord

Photo 3: Great black wasp (Sphex pensylvanicus) on left

Karl Foord

Photo 4: Great black wasp (Sphex pensylvanicus) and golden digger wasp (Sphex ichneumoneus) on Culver's Root (Veronicastrum virginicum)


I am not sure what I expected when I created this pollinator garden (photo 1), but I have certainly gotten a whole new perspective on what happens in a flower garden. I have encountered so many different species that I will create a series of pollinator garden observations. I will begin with wasps and follow up with many types of flies and bees.

The garden has been continually patrolled by a great black wasp (Sphex pensylvanicus). This wasp is perceived as a black streak that weaves its way around the different plants in the garden searching for prey (photos 2 & 3). It only rarely lands to fuel up on nectar at a Culver's Root plant (Veronicastrum virginicum) seen here with a golden digger wasp (Sphex ichneumoneus) (photo 4). It sometimes hassles other residents. I have seen it touch the back of bumblebees who fly in response but are not harmed. It had an encounter with a hummingbird but both went their separate ways.




Karl Foord


Photo 5: bald-faced hornet (Dolichovespula maculata)



I encountered a bald-faced hornet (Dolichovespula maculata) gathering nectar on Summer Beauty Onion (Allium lusitanicum 'Summer Beauty'). It looked to have enough hairs to actually be accomplishing some transfer of pollen.




Karl Foord


Photo 6: Thick-headed Fly (family Conopidae)



Another interesting character was this Thick-headed Fly (family Conopidae) whose thread-waist mimics that of the Sphecid wasps. The thick-headed fly was on Hoary Vervain (Verbena stricta).

Karl Foord

Photo 7: Cuckoo Wasp (Family Chrysididae)

Lastly we have a iridescent well armored Cuckoo wasp (Family Chrysididae) (photo 7). This wasp is parasitic on other wasps, laying its eggs in the already provisioned nests of other wasps.




Karl Foord


Photo 7: Cuckoo Wasp (Family Chrysididae)


A well camouflaged female Goldenrod Crab Spider (Misumena vatia ) was quite tentative around this customer. I have seen crab spiders with captured flower flies and butterflies, but this wasp may have been too well armored to warrant an attack.

Karl Foord

Photo 8: Cuckoo Wasp (Family Chrysididae) and Goldenrod Crab Spider (Misumena vatia)

The other interesting thing is that I am sure there are at least 10 other species of wasps in the garden that I have observed but not yet identified. To be continued...

Editor's note: The primary reference for this article was Jeff Hahn's book Insects of the North Woods. The spider was identified through Larry Weber's book Spiders of the North Woods. Thanks to both of these authors.

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Karl Foord

Photo 1: Gooseneck Loosestrife ( Lysimachia clethroides)


Gooseneck Loosestrife

Karl Foord

Photo 2: Variegated Japanese Knotweed (Fallopia japonica 'Variegata'.)


Variegated Japanese Knotweed




Karl Foord


Photo 3: Goatsbeard (Aruncus dioicus)



Goatsbeard




Karl Foord


Photo 4a: Jack-in-the-Pulpit (Arisaema triphyllum)


Karl Foord

Photo 4b: Jack-in-the-Pulpit (Arisaema triphyllum)

Jack-in-the-Pulpit

Karl Foord

Photo 5: Siberian Bugloss (Brunnera macrophylla)


Siberian Bugloss Brunnera

Dry Shade

Editors note: These videos were filmed in 2012

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Karl Foord

Photo 1: Flowering Onion (Allium spp.)

Flowering Onion




Karl Foord


Photo 2: Our host Dr. Mary Meyer showing the William Baffin Rose


William Baffin Climbing Rose

Karl Foord

Photo 3: May Night Salvia (Salvia x sylvestris 'Mainacht'

May Night Salvia

Karl Foord

Photo 4: Gas Plant (Dictamnus albus)


Gas Plant

Karl Foord

Photo 5: Ozark Sundrops (Oenothera macrocarpa)

Ozark Sundrops Oenothera

Little Rocket Ligularia

Karl Foord

Photo 6: Little Rocket Ligularia (Ligularia stenocephala 'Little Rocket')

Lamb's Ear

Karl Foord

Photo 7: Lamb's Ear (Stachys byzantina)

Editors note: These videos were filmed in 2012

Observations from a Pollinator Garden

Karl Foord - Extension Educator, Horticulture

I just returned from a two week absence from my garden due to training and a vacation, and I was anxious to see how things had progressed.

Karl Foord

Photo 1: Leaf with holes created by leaf-cutter bees

The first thing I saw was an 'Autumn Blaze' maple volunteer on the edge of my sidewalk. Normally this would be simply a weed to pull, BUT in this case the maple leaves told an interesting story. The holes in the leaves were clearly the work of leaf-cutter bees (Megachile spp.) (photo 1). Notice that the holes cut by the bees have two different shapes. One shape is a circle (photo 2) best for plugging nesting holes, and another shape is oblong best for lining nesting holes (photo 3).




Karl Foord


Photo 2: Round holes for plugging tunnels


Karl Foord

Photo 3: Oblong holes for lining tunnels

And sure enough the leaf-cutter bee was found working a flower on Hoary Vervain (Verbena stricta) (photo 4).

Karl Foord

Photo 4: Leaf-cutter bee (Megachile spp.) on Hoary Vervain (Verbena stricta)

Also observed was an Andrenid bee on Birds-foot Trefoil (Lotus corniculatus)




Karl Foord


Photo 5: Andrenid bee on Birds-foot Trefoil (Lotus corniculatus)


Karl Foord

Photo 6: Male Widow Skimmer (Libellula luctuosa)

Karl Foord

Photo 7: Male Widow Skimmer (Libellula luctuosa) perching after having caught prey

Another fascinating creature resident in the pollinator garden was a male Widow Skimmer (Libellula luctuosa) coming in for a landing (photo 6) and perching after having caught prey (photo 7).

The garden continues to provide compelling theatre for the patient and observant. Please enjoy your garden!

Impatiens downy mildew already making an appearance in MN landscapes

M. Grabowski

Photo 1: Impatiens showing symptoms of downy mildew

Michelle Grabowski, UMN Extension Educator


The extended cool wet weather present throughout much of Minnesota has brought out the symptoms of impatiens downy mildew early this year. Plants infected with impatiens downy mildew drop their blossoms and have yellow stippled leaves that curl under at the edges. As the disease progresses, infected leaves fall off, leaving barren green stalks, which flop to the soil like cooked spaghetti noodles with time. Plants that are infected very young often remain small and yellow, dropping leaves and collapsing before they can ever grow to maturity.

The pathogen responsible for impatiens downy mildew is Plasmopara obducens, a water mold that thrives in cool wet conditions. Spores of the pathogen can be seen as fluffy white growth on the lower surface of infected leaves. These spores are easily spread on wind and splashing rain.

M.Grabowski, UMN Extension

Photo 2: Sporulation of downy mildew on the lower surface of an infected leaf

Gardeners observing symptoms of downy mildew on impatiens should remove plants immediately. Once spores of the pathogen have been found on the plant, there is no way to prevent its eventual decline from disease. Impatiens downy mildew only infects some species of impatiens. All varieties of Impatiens walleriana, standard impatiens, are highly susceptible to the disease. In gardens where the disease has been found, other shade annuals like begonia, coleus, and caladium are good choices for replacement plants. New Guinea impatiens, Impatiens hawkeri, are resistant to the disease and can also be planted in beds with a history of disease.

Some fungicides can protect healthy impatiens from infection with downy mildew but most are unavailable to home gardeners. Gardeners interested in protecting impatiens from downy mildew should contact a landscape professional with a pesticide applicators license to treat plants. More information about impatiens downy mildew can be found at the UMN Extension Garden webpage.

Spring Flowering Bulbs

Karl Foord - Extension Educator, Horticulture

The recent snowfall and lower than normal temperatures should not harm the flowers derived from spring flowering bulbs. Low temperatures above 28 F and day temperatures in the 30s and 40s will not harm these cold tolerant frost tolerant plants.

However, if the temperatures drop into the low 20s or high teens, these plants can be injured.

Enjoy these hints of spring.

Fascinating Fragrances - Three Perspectives

Karl Foord - Extension Educator, Horticulture


If someone hands you a flower, what is the first thing you do? Smell it, of course. How often have you exercised this ingrain behavior only to come up empty?

My colleague and a contributing writer to this blog, Robin Trott sells cut flowers for a living and reports, "I feel cheated when beautiful flowers lack fragrance. I insist on having fragrant flowers in the bouquets I sell. To provide fragrance, we use herbs such as basil, lavender, mint, dill, and cilantro as fillers, and grow stock (Matthiola spp.) fragrant snapdragons (Antirrhinum spp.), Sweet Williams (Dianthus barbatus) and fragrant oriental lilies (Lilium spp.)".




www.nps.gov


Photo 1: Testing flowers for fragrance


The Human Perspective

Fragrances have been a part of human culture for a long time. The mere presence of flowers has been shown to have positive effects on human emotions, and recent research has shown that fragrant flowers are a "positive emotion inducer". This should come as no surprise to most gardeners.

Breeding improvements in flowers have rarely included fragrance characteristics, which were considered to have a negative effect on vase life. Recent studies on fragrance suggest that this might not be the case, and researchers at David Austin Roses are making progress in improving the vase life of fragrant roses. I find it quite encouraging that researchers are working to strengthen a plant characteristic that positively effects a person's overall enjoyment of a flower.


As an avid gardener, fragrant plants are a significant addition to my landscape. Killing four-lined plant bugs or weeding in my mint patch becomes much less of a pain when accompanied by the scent of mint. Sitting on the deck when the Wisteria is in bloom is a sensory gift. Fortunately, there are quite a few plants that offer the reward of fragrance.

The Plant's Perspective

Fragrance provides a vital service for the plant. A plant's distinct aroma attracts pollinators, thereby facilitating cross-pollination and the continuation of the species. The relationship that exists between the plant and the pollinator is one of intimacy and endurance. To experience the optimal range of plant fragrances, it is important to understand the plant's pollination strategy. For example, plants pollinated by moths produce optimum fragrance in the evening as moths are nocturnal. Thus Nicotiana is more fragrant at night, when its moth pollinators are out and about. Plants pollinated by bees produce optimum fragrance during the day as bees are diurnal. Thus snapdragons are more fragrant during the day, when its bee pollinators are likely to be active.
Different but specific fragrances also help to ensure that insects visit flowers of a similar species, increasing the potential for successful cross-pollination. From a long distance, flower fragrances are more effective than visual signals in attracting a pollinator, especially to small or hidden flowers. Flower fragrances tend to be at their highs when they have sufficient nutrition.

In addition, moderate to warm temperatures and high light tend to increase fragrances. For instance, roses are picked at night when they are at their most fragrant, whereas jasmine flowers are harvested when their fragrance is at its peak just before dawn.
Every plant has its own signature scent, a complex mixture of so-called volatile organic compounds that easily turn to gases and waft through the air. Some 1,700 different compounds from 990 different plants have been identified in flower fragrances so far, according to Natalia Dudareva, a Purdue University biologist whose specialty is floral scents.

To extend your garden fragrance window, why not grow the nectar plants that pollinators on the night shift prefer. Good candidates for moths include native night bloomers such as evening primroses, yuccas, phlox, sacred datura and evening snow. To attract giant silk moths, grow the host plants of their caterpillars. Oak, sassafras, maple, birch, ash, willow and cherry are a few favored larval plants.

www.rhsmpsychology.com

Photo 2: Human olfactory apparatus

The Insect's Perspective

Honey bees (Apis millifera) have 170 odorant receptors, the researchers found, compared with 62 in fruit flies (Drosophila melanogaster) and 79 in mosquitoes (Anopheles gramblae). The enhanced number of odorant receptors underlies the honey bee's remarkable olfactory abilities, including perception of pheromones, kin recognition signals, and social communication within the hive. Honey bees also use odor recognition for finding food. University of Illinois Entomology professor, Hugh Robertson, who has conducted research on the honeybee genome, states: "Foraging worker bees might encounter a bewildering number of flowers to choose from, but they can discriminate between them using subtle olfactory cues," He goes on to say that "A large number of odorant receptors allows the bees to find food and communicate its location to other bees." In striking contrast, the researchers found only 10 gustatory receptors in A. millifera, compared with 68 in D. melanogaster and 76 in A. gramblae. Clearly taste is more important to fruit flies and mosquitoes than it is for bees.

www.argosymedical

Photo 3: Comparison of dog vs. human olfactory apparatus

Our olfactory apparatus

The human sense of smell is carried out by two small odor-detecting patches. Each patch is slightly less than ½ of a square inch and contains some 2.5 to 3 million receptor cells (photo 2). For comparison, a dog has 220 million of these olfactory receptors (photo 3). Nonetheless, humans can distinguish more than 10,000 different smells and are capable to detect certain substances in dilutions of less than one part in several billion parts of air.

Extend your garden's fragrance window

Grow the nectar plants that pollinators on the night shift prefer. Good candidates for moths include:
* Night Gladiolus: (Gladiolus tristus) has creamy yellow blossoms that have an intense spicy fragrance at night.
* Pinks: (Dianthus plumarius) The pale pink flowers have a rich clove scent.
* Evening Primrose: (Oenothera) With sweetly-scented blossoms of soft white, pink and bright yellow that open in the evening.
* Moonflowers: (Ipomoea alba) This night-blooming relative of the morning glory perfumes the garden as its large 5 to 6 inch white flowers open at dusk. A quick growing climber with large heart-shaped leaves.
* Evening Stock: (Matthiola incana) Small pink or purplish flowers are not showy, but emit an intoxicating fragrance at night. Grows to one foot with lance-shaped leaves.
* Four O'Clocks: (Mirabilis jalapa) Sweetly fragrant and colorful trumpet-shaped flowers, open in late afternoon releasing a jasmine-like perfume. Found in the gardens of Thomas Jefferson at Monticello, the bushy plants grow 24 inches tall and are an annual in our climate.
* Daylilies: there are many daylilies that bloom at night including 'Moon Frolic' and 'Toltec Sundial'.

More information about night blooming plants

Hellebores Come in Many Colors

Robin Trott, University of Minnesota Extension Educator


Lasts month's article highlighted the wonderful Christmas Rose (Helleborus
niger
). Selected varieties within this species have a similarly constructed inflorescence, bloom ivory to clear white fading to rose and green in maturity, and have slightly different bloom times.

If you're looking for an early spring bloom that is colorful, consider hybrid hellebores. Here are a few colored varieties, hardy to zone 4, that you might like to try in you perennial garden.

Jelitto Seed

Photo 1: Double Ladies mix (Helleborus x hybridus 'Double Ladies')

Double Ladies
(H. x hybridus: 15-18" tall, 24" wide) has leathery, semi-evergreen foliage with large double flowers in shades of white, yellow, red, pink and purple (see Photo 1). This early bloomer prefers partial to full shade and is recommended for use as an accent plant, or planted in large drifts in your shade garden.

Jelitto Seed

Photo 2: Picotee Lady (Helleborus x hybridus 'Picotee Lady')


Picotee Lady

(H. x hybridus: 15-18" tall, 24" wide) is also a semi-evergreen plant. Its greenish white flowers have pink/red veining, and each petal is edged a dark red (See Photo 2). Picotee Lady makes a great cut for floral arrangements. Preferring partial - full shade, this hellebore thrives in shade beds and borders, and woodland gardens.

Skagit Gardens

Photo 3: Ivory Prince (Helleborus niger 'Walhelivor')

Ivory Prince
(H. 'Walhelivor':12-18" tall, 24" wide) has blue/green, shrub-like foliage. The abundant ivory blossoms have a pink/chartreuse blush and green veining (See Photo 3). Blooming in very early spring, this plant prefers moist, well-drained soil; water generously for your best bloom. This compact hellebore is divine in containers and in shade borders.


Winter Jewels Series
The Winter Jewels Series has a spectacular display of color. This series is the Orientalis variety (Helleborus x hybridus), also known as Lenten rose. These cultivars have large, nodding blossoms which come in a wide range of colors, and the foliage is deer resistant! Use Winter Jewels to brighten up your shady nooks and add color and texture to your woodland and rock gardens. H. x hybridus generally doesn't bloom the first year, but they are so stunning, that they are worth the wait.

Skagit Gardens

Photo 4: Winter Jewels Cherry Blossom (Helleborus x hybridus 'Cherry Blossom')

WJ Cherry Blossom: (18-22" tall, 24" wide) Dark green foliage highlighted with white blooms speckled with cherry red, and a red starburst center (Photo 4).

Skagit Gardens

Photo 5: Winter Jewels Golden Sunrise (Helleborus x hybridus 'Golden Sunrise')

Skagit Gardens

Photo 6: Winter Jewels Apricot Blush (Helleborus x hybridus 'Apricot Blush')

Skagit Gardens

Photo 7: Winter Jewels Black Diamond (Helleborus x hybridus 'Black Diamond')

Skagit Gardens

Photo 8: Winter Jewels Painted (Helleborus x hybridus 'Painted')

WJ Golden Sunrise: (18-22" tall, 24" wide) Light yellow/green foliage contrasted with flowers in shades of yellow. The petal backs are blush colored, the fronts are red veined with a red starburst center (Photo 5).

WJ Apricot Blush: (20" tall, 24" wide) Blossoms in shades white, blushed with rosy apricot. Medium green foliage (Photo 6).

WJ Black Diamond: (15-18" tall, 22" wide) Purple foliage matures to green. Blooms are nearly black, tinted slate, burgundy and red. These are spectacular paired with bright yellows and greens (Photo 7).

WJ Painted: (18-22" tall, 24" wide) Medium-dark green foliage brightened by white blossoms painted with burgundy (Photo 8).

Planting
Plant all Hellebores in humus-rich, well-drained soil, and water regularly. Protect them from harsh winter conditions. Plant in a protected location and cover with mulch once the ground has frozen to avoid winter kill. Remove the dead leaves in the spring.

Hellebores are reliably cold hardy season starters that are good in containers, shade gardens, woodland gardens and rock gardens. They maintain their green foliage late into the season, and are virtually deer resistant. If you are interested in trying these versatile perennials in your shade beds next spring, contact your local nursery or garden center for availability.

Christmas Rose (Helleborus niger)


Robin Trott, University of Minnesota Extension Educator


I know the growing season is officially over when we make our annual trek to the Association of Specialty Cut Flower Growers conference. This time we travelled to Tacoma, WA, and had the great pleasure of visiting growers in the Skagit Valley, north of Seattle. This year's particular delight was visiting Skagit Gardens and beholding their greenhouses filled with hellebores.

Skagit Gardens

Photo 1: Skagit Gardens Greenhouse of hellebores




Skagit Gardens


Photo 2: Skagit Garden's Greenhouse of hellebores


This alpine plant grows native at high elevations and produces large white flowers that turn a blushy pink as they age. Until recently, these perennial plants (hardiness zone 4-9 depending on species) were the sole domain of rare plant collectors, with prices way beyond the pocket book of average consumers. With the breeding programs developed at Skagit and other wholesale nurseries, a variety of cultivars are available at garden centers nationwide.

Hellebores are anatomically separated into 2 groups, "caulescent" and "acaulescent". Caulescent hellebores are those with above-ground stems (Figure 1). Acaulescent plants are those where the flowers are born on their own stalk with no leaves, and the leaves have their own stalk (Figure 2). Caulescent varieties are popular for use by florists in dramatic arrangements.

M. Talt (GardenGuides.com)

Figure 1: Caulescent Species of Helleborus




M. Talt (GardenGuides.com)


Figure 2: Acaulescent Species of Helleborus



The Christmas rose is the best known and certainly the showiest of the species hellebores (Photo 3).




Skagit Gardens


Photo 3: Christmas rose (Helleborus niger)


Easier to grow than the ever popular "Poinsettia", plant breeders like Skagit are hoping to promote this flower as the new and improved holiday potted plant which can later be transplanted in perennial beds to bring joy year after year.

If you select a hellebore as a holiday accent this year, keep these horticultural tips in mind:

For indoors care, keep your plant in a bright cool location, away from any heat source. (Hellebores will bloom through snow, they like it cold!) Keep the soil moist; don't let the plant dry out! Don't worry if your hellebore gradually yellows, this is natural. If you are concerned, move it to a cooler location. Plant your hellebore outside in partial to full shade as soon as the ground has thawed. Protect your transplant from weather extremes until it has become established.

Once transplanted, mulch your hellebore to keep the soil cool and moist throughout the summer months. Make sure you have selected a site that is protected from desiccating winds. The new breeding of these beauties has made them disease and insect resistant. Once established, they require minimum additional care. Deer don't touch hellebores, which is an added bonus to this delightful flowering plant.

Although each variety holds it blooms for a lengthy period, during which time the flowers turn from pure white to pinkish green, you can increase your bloom time by selecting several different cultivars.

Jacob: the traditional "Christmas Rose" will bloom as soon as the frost begins to leave the ground in the spring. It is a compact plant (9-12"x 13" spread) with pure white slightly fragrant blossoms atop burgundy stems.

Skagit Gardens

Photo 4: 'Jacob' Lenten Rose (Helleborus niger 'HGC Jacob')

Josef Lemper: another Helleborus niger is a taller (15-18"x 21"spread) early bloomer.

Skagit Gardens

Photo 5: Josef Lemper Lenten Rose (Helleborus niger 'HGC Josef Lemper')

'Winter's Bliss': Is a later blooming variety whose large white blossoms fade to deep pink with age. It grows 15-18" with a 24" spread.

Skagit Gardens

Photo 6: 'Winter's Bliss' Lenten Rose (Helleborus x ericsmithii 'HGC Champion')

Joshua is a 12-15" early blooming variety with a 17" spread. Its slightly fragrant white blooms age to light green. Its foliage is glossy dark green and works well as filler in your springtime arrangements.

Skagit Gardens

Photo 7: Joshua Lenten Rose (Helleborus niger 'HGC Joshua'

Silvermoon: (15-18"x21") has creamy blossoms tinged in pink atop rose colored stems.




Skagit Gardens


Photo 8: 'Silvermoon' Lenten Rose (Helleborus x ericsmithii 'HGC Silvermoon'



This is just a small sampling of varieties that are hardy to USDA Zone 4, and thrive in Minnesota Gardens. Check with your local garden center this spring for varietal availability.


Plant NOW for Dazzle next Spring

Karl Foord - Extension Educator, Horticulture

I always have mixed feelings about fall. I know plants, animals, and insects have cycles, but it is depressing to see the hummingbirds leave, the plants die or go dormant, and the insects die or hibernate. In the spirit of acceptance of such things I would choose to focus on the spring when many things "come back" to life. One of the great joys of spring is watching the spring flowering bulbs pop through the ground and bring color to a bleak landscape. To enjoy this one must act now and plant. To appreciate the joys to come I have collected the Flowering Plant Video Library entries featuring spring flowering bulbs and organized them by flowering time somewhat following Chart 1. which also appears in the yard and garden brief: Spring Flowering Bulbs.




Y&G Brief


Chart 1: Spring Flowering Bulbs Planting Chart


General Recommendations:

1. Plant in odd numbered groups or mass plantings.
2. Plant where they can be seen from a favorite window in the house.
3. Planting depth and spacing depends on the individual bulb. Generally bulbs are planted 2.5 times their diameter. In light sandy soils plant 1 - 2 inches deeper and in heavy clay soils 1 - 2 inches more shallow.
4. Protect bulbs from hungry critters

See articles below for specific bulbs.

Plant Some Early Spring Flowering Bulbs

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture




Karl Foord


Photo 1: Striped Squill (Puschkinia scilloides var. libanotica)


Striped Squill (Puschkinia scilloides var. libanotica)

Karl Foord

Photo 2: Snowdrops (Galanthus nivalis)


Snowdrops (Galanthus nivalis)




Karl Foord


Photo 3: Siberian Squill (Scilla siberica)


Siberian Squill (Scilla siberica)

Karl Foord

Photo 4: Glory of the Snow (Chionodoxa luciliae)


Glory of the Snow (Chionodoxa luciliae)

Karl Foord

Photo 5: Checkered Lily (Fritillaria meleagris)



Checkered Lily (Fritillaria meleagris)




Karl Foord


Photo 6: Species Tulips (Tulipa tarda)



Species Tulips (Tulipa tarda)

Karl Foord

Photo 7: Garden Hyacinth (Hyacinthus orientalis)



Garden Hyacinth (Hyacinthus orientalis)

Karl Foord

Photo 8: Grape Hyacinth (Muscari armeniacum)


Grape Hyacinth (Muscari armeniacum)

Plant Some Mid and Late Spring Flowering Bulbs

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Karl Foord

Photo 1: Triumph Tulip (Tulipa 'Gavota')

Triumph Tulip (Tulipa 'Gavota')

Karl Foord

Photo 2: Daffodils(Narcissus spp.)

Daffodils (Narcissus)

Karl Foord

Photo 3: Ornamental Onions (Allium spp.)

Ornamental Onions (Allium spp.)


Flowering Plant Video Library - Some Early Fall Flowering Plants I

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Fireworks Goldenrod (Solidago rugosa 'Fireworks')




Karl Foord


Photo 1: Fireworks Goldenrod (Solidago rugosa 'Fireworks')


Karl Foord

Photo 2: Fireworks Goldenrod (Solidago rugosa 'Fireworks')

Rozanne Geranium (Geranium 'Rozanne')

Karl Foord

Photo 3: Rozanne Geranium (Geranium 'Rozanne')

Lesser Calamint (Calamintha nepeta)




Karl Foord


Photo 4: Lesser Calamint with Sweat Bee (Calamintha nepeta)





Karl Foord


Photo 5: Lesser Calamint with Honeybees (Calamintha nepeta)


Flowering Plant Video Library - Some Early Fall Flowering Plants II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Giant Amaranth (Amaranthus cruentus)

Karl Foord

Photo 1: Giant Amaranth (Amaranthus cruentus)


Savannah Ruby Grass (Melinis nerviglumis 'Savannah')

Karl Foord

Photo 2: Savannah Ruby Grass (Melinis nerviglumis 'Savannah')


Russian Sage (Perovskia atriplicifolia)



Karl Foord


Photo 3: Russian Sage (Perovskia atriplicifolia)



Lesser Calamint (Calamintha nepeta)



Karl Foord


Photo 4: Lesser Calamint with Sweat Bee (Calamintha nepeta)





Karl Foord


Photo 5: Lesser Calamint with Honeybees (Calamintha nepeta)



Little Titch Catmint (Nepeta racemosa 'Little Titch')

Karl Foord

Photo 6: Little Titch Catmint (Nepeta racemosa 'Little Titch')

Flowering Plant Video Library - Late Summer Flowering Annuals II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture


Broomcorn (Sorghum vulgare)

Karl Foord

Photo 1: Broomcorn (Sorghum vulgare)

Sweet William (Dianthus barbatus)




Karl Foord


Photo 2: Sweet William (Dianthus barbatus)



Indian Blanket (Gaillardia pulchella)




Karl Foord


Photo 3: Indian Blanket (Gaillardia pulchella)


Flowering Plant Video Library - Late Summer Flowering Perennials II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture


Turtlehead (Chelone lyonii)

Karl Foord

Photo 1: Turtlehead (Chelone lyonii)

Boneset (Eupatorium maculatum)




Karl Foord


Photo 2: Boneset (Eupatorium maculatum)



Canada Goldenrod (Solidago canadensis)




Karl Foord


Photo 3: Canada Goldenrod (Solidago canadensis)


Downy Mildew on Impatiens Drops Leaves Across Minnesota

Michelle Grabowski, University of Minnesota Extension Educator

M. Grabowski, UMN Extension/p>

Photo 1: Impatiens infected with downy mildew

Earlier this year we warned gardeners to be on the look out for downy mildew on impatiens. As we anticipated the downy mildew pathogen is here in Minnesota and many gardeners are now observing symptoms of this disease. Impatiens that have yellow lower leaves or look like naked stems due to leaf drop should be closely inspected. Downy white growth on the lower surface of the leaves can be used to confirm the disease. For more information about downy mildew on impatiens visit our previous disease alert.

Flowering Plant Video Library - Late Summer Flowering Bulbs

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Lavender Globe Lily & Curly Garlic Chives (Allium spp.)

Karl Foord

Photo 1: Curly Garlic Chives (Allium spirale)


Autumn Lily - Late Summer Flowers (Lycoris squamigera)

Karl Foord

Photo 2: Autumn Lily Flowers (Lycoris squamigera)


Lavender Glove Lily (Allium tanguticum 'Summer Beauty')




Karl Foord


Photo 3: Cleome or Spider Flower (Cleome hasslerana)



Blackberry Lily (Belamcanda chinensis)




Karl Foord


Photo 4: Blackberry Lily (Belamcanda chinensis)



Flowering Plant Video Library - Late Summer Flowering Annuals

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Flowering Tobacco (Nicotiana sylvestris)




Karl Foord


Photo 1: Flowering Tobacco (Nicotiana sylvestris)


Karl Foord

Photo 2: Flowering Tobacco (Nicotiana sylvestris)

Cleome or Spider Flower (Cleome hasslerana)




Karl Foord


Photo 3: Cleome or Spider Flower (Cleome hasslerana)



Pot Marigold (Calendula officinalis)

Karl Foord

Photo 4: Pot Marigold (Calendula officinalis)

Flowering Plant Video Library - Late Summer Flowering Perennials

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Joe-Pye Weed (Eupatorium purpureum 'Gateway')




Karl Foord


Photo 1: Joe Pye Weed (Eupatorium purpureum 'Gateway')


Hardy Hibiscus, Rose Mallow (Hibiscus moscheutos 'Blue River II')




Karl Foord


Photo 2: Hardy Hibiscus Rose Mallow (Hibiscus moscheutos 'Blue River II)



Balloon Flower (Platycodon grandiflorus)

Karl Foord

Photo 3: Balloon Flower (Platycodon grandiflorus)

Lesser Calamint (Calamintha nepeta)




Karl Foord


Photo 4: Lesser Calamint with Sweat Bee (Calamintha nepeta)





Karl Foord


Photo 5: Lesser Calamint with Honeybees (Calamintha nepeta)


Milkweed - Butterfly Magnet - Part I: Brushfoots

Karl Foord - Extension Educator, Horticulture

I was vacationing at Scenic State Park last month, and while driving down the road to Big Fork I saw a patch of common milkweed (Asclepias syriaca) along the roadside (Photo 1). I decided to stop and see if milkweed's reputation as a butterfly magnet was truly deserved.




Karl Foord


Photo 1: Milkweed Patch



I stood in the patch for an hour. It was like being in a natural butterfly house. The amount of activity was amazing. I would estimate there to have been at least 100 butterflies in this approximately 15' x 20' patch. There was also a dizzing array of butterfly species. I have attempted to record this diversity with photographs, and using Larry Weber's Butterflies of the North Woods, have identified 26 different species.

I will divide the findings into three articles; brushfoots, skippers, and a collection of sulphurs, coppers, hairstreaks, and day-flying moths.




Karl Foord


Photo 2: Monarch Adult and Caterpillar





Karl Foord


Photo 3: Admiral and Ladies


Karl Foord

Photo 4: Great Spangled and Atlantis Fritillaries - upper wing

Karl Foord

Photo 5: Great Spangled and Atlantis Fritillaries - under wing side view




Karl Foord


Photo 6: Aphrodite Fritillary and Common Wood-Nymph


Karl Foord

Photo 7: Crescents


Milkweed - Butterfly Magnet - Part II: Skippers

Karl Foord - Extension Educator, Horticulture

This is a continuation of the butterflies encountered in a roadside milkweed patch.

Karl Foord

Photo 1: Peck's and Delaware Skippers




Karl Foord


Photo 2: Silver-spotted and Least Skippers


Karl Foord

Photo 3: Long Dash and Dion Skippers




Karl Foord


Photo 4: Dun Skippers - Male and Female





Karl Foord


Photo 5: Unidentified Skipper



Milkweed - Butterfly Magnet - Part III: Sulphurs, Coppers, Hairstreaks, & Day-flying Moths

Karl Foord - Extension Educator, Horticulture

This is a continuation of the butterflies encountered in a roadside milkweed patch.

Karl Foord

Photo 1: Clouded and Orange Sulphurs

Karl Foord

Photo 2: Pink-edged Sulphur




Karl Foord


Photo 3: Bronze Copper and Acadian Hairstreak Butterflies





Karl Foord


Photo 4: Day-flying Moths


In conclusion, I would have to say that milkweed certainly lives up to its reputation as a butterfly magnet. I am looking for a place to establish a milkweed patch and invite the butterflies.

Powdery Mildew on Peonies

Michelle Grabowski, UMN Extension Educator

M.Grabowski, UMN Extension

Photo 1: Powdery Mildew on Peony

If your peonies look like they have been dusted with flour this summer, the likely culprit is powdery mildew. Powdery mildew is a fungal disease caused by Erysiphe polygoni. Several scientists have noted that powdery mildew on peony seems be an emerging problem in landscape plantings in recent years. Although powdery mildew is a common disease problem on garden plants like phlox and bee balm, many gardeners have grown peonies for decades without powdery mildew until recently.


Powdery mildew is unlikely to kill a peony plant. In fact the fungus can only feed on live plant cells. The powdery mildew fungus covers peony leaves and stems with powdery spores and fine fungal strands known as mycellia. Spores are spread from plant to plant on wind currents. In the early stages of infection, powdery mildew colonies look like fluffy snowflakes resting on the leaf surface. these infections quickly expand to cover the entire leaf surface in powdery white to gray fungal growth.

M.Grabowski, UMN Extension

Photo 2: Early infections of Powdery Mildew

Powdery mildew is more common in plants that are growing in shade and have poor air movement, as these conditions favor fungal growth. Planting peonies in full sun with good air movement around plants can help reduce problems with powdery mildew. If peonies are suffering from powdery mildew there is little that can be done this summer. Preventative fungicides can be applied when the first few leaf spots appear earlier in the year. Fungicides, however, are not necessary to protect the health of the plant and many gardeners simply choose to tolerate the white coating that shows up at the end of summer.


The amount of powdery mildew that appears often varies from year to year depending on weather conditions. So having heavily infected plants this year is no guarantee that the problem will occur to the same degree in following years. As with all leaf spot diseases, it is a good idea to remove infected plant debris from the garden to prevent overwintering of the pathogen. Infected plant debris can be brought to a municipal compost facility or composted in a backyard compost pile that heats up.

Flowering Plant Video Library - Prairie Plants III

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture


Wild Bergamot (Monarda fistulosa)




Karl Foord


Photo 1: Wild Bergamot (Monarda fistulosa)



Compass Plant (Silphium laciniatum)

Karl Foord

Photo 2: Compass Plant (Silphium laciniatum)


Rosinweed (Silphium integrifolium)

Karl Foord

Photo 3: Rosinweed (Silphium integrifolium)


Side-oats Grama (Bouteloua curtipendula)




Karl Foord


Photo 4: Side-oats Grama (Bouteloua curtipendula)


Indian Grass (Sorghastrum nutans)




Karl Foord


Photo 5:Indian Grass (Sorghastrum nutans)



Follow up to June 15 article on Swamp Milkweed

Karl Foord - Extension Educator, Horticulture

In the article Swamp Milkweed - Great for Nectar - Bizarre Flowers that appeared in the June 15 Issue of Yard and Garden News, I lamented the fact that I had no pictures of insects carrying the pollinia of milkweed.

Although the pictures in this article are of insects on common milkweed (Asclepias syracia) and not Swamp Milkweed (Asclepias incarnata) the flowers are similar enough to be applicable.

Please note the pollinia on both a native bee and a fritillary butterfly.




Karl Foord


Photo 1: Milkweed Pollinia taking a ride on a native bee





Karl Foord


Photo 2: Pollinia taking a ride on a Great Spankled Fritillary (Speyeria cybele)


Flowering Plant Video Library - Prairie Plants II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Purple Prairie Clover (Dalea purpurea)

Karl Foord

Photo 1: Purple Prairie Clover (Dalea purpurea)


False Indigo (Baptisia australis)

Karl Foord

Photo 2: False Indigo (Baptisia australis)


Prairie Dock (Silphium terebinthinaceum)

Karl Foord

Photo 3: Prairie Dock (Silphium terebinthinaceum)


Cup Plant (Silphium perfoliatum)

Karl Foord

Photo 4: Cup Plant (Silphium perfoliatum)


Harebell Campanula (Campanula rotundifolia)

Karl Foord

Photo 5: Harebell Campanula (Campanula rotundifolia)


Native Prairie Lily (Lilium philadelphicum)




Karl Foord


Photo 6: Native Prairie Lily (Lilium philadelphicum)



Golden Alexanders (Zizia aurea)

Karl Foord

Photo 7: Golden Alexanders (Zizia aurea)


Flowering Plant Video Library - Prairie Plants I

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture


Common Milkweed (Asclepias syriaca)

Karl Foord

Photo 1: Common Milkweed (Asclepias syriaca)


Foxglove Beardtongue (Penstemon digitalis)

Karl Foord

Photo 2: Foxglove Beardtongue (Penstemon digitalis)

Prairie Phlox (Phlox pilosa)

Karl Foord

Photo 3: Prairie Phlox (Phlox pilosa)


White Wild Indigo (Baptisia alba)



Karl Foord


Photo 4: White Wild Indigo (Baptisia alba)



Common Ox-eye (Heliopsis helianthoides)



Karl Foord


Photo 5: Common Ox-eye (Heliopsis helianthoides)


Butterfly Milkweed (Asclepias tuberosa)



Karl Foord


Photo 6: Butterfly Weed (Asclepias tuberosa)


Swamp Milkweed - Great for Nectar - Bizarre Flowers

Karl Foord - Extension Educator, Horticulture

Swamp Milkweed (Asclepias incarnata) as you know is an important plant for Monarch Butterflies. The plant also produces significant amounts of nectar and thus attracts a host of other pollinators including various bees and ants (Photo 1).

Karl Foord

Photo 1: Milkweed flower (Asclepias incarnata)

On close examination the flower structure is bizarre. Typical corollas face backward (Photo 1), whereas prominent coronas fold to form a tube of sorts out of which a horn projects toward the center of the flower. The stamens have fused to form a cylinder around the pistil with a pink stigmatic surface in the center (Photo 2).




Karl Foord


Photo 2: Milkweed flower (Asclepias incarnata) close-up of unpollinated flower


Pollen has fused to form wings called pollinia which are connected by a dark pollinarium gland, the whole structure being called a pollinarium. You can see the wings protruding from the side of the fused staminal column (Photo 2). The strategy is for an insect to visit the plant looking for nectar and catch its leg on one of the pollinia wings which detaches from the plant and attaches to the insects leg. The insect carries the pollinarium to another flower where the horn may help in detachment placing pollen on the stigmatic surface.




Karl Foord


Photo 3: Milkweed flower (Asclepias incarnata) close-up of pollinated flower



I took many pictures hoping to find an insect with a pollinarium attached to its leg. Alas I did not find one. However, I did find pollinarium that had been transferred from another flower. They can be seen in Photo 3 where the top center section has three pollinarium and the top left section has two pollinarium where originally each had only one.

Flowering Plant Video Library - Peonies

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Fern Leaf Peony (Paeonia tenuifolia 'Little Red Gem')

Tree Peony (Paeonia suffruticosa 'Guardian of the Monastery')

Karl Foord

Photo 1: Guardian of the Monastery Tree Peony

Karl Foord

Photo 2: Guardian of the Monastery Tree Peony


Common Garden Peony (Paeonia lactiflora 'Chalice')

Karl Foord

Photo 3: Common Garden Peony 'Reward'


Garden Peony Growing Recommendations

Plant Video Library - Lilacs

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Dwarf Korean Lilac (Syringa meyeri)

Miss Kim Korean Lilac (Syringa pubescens subsp. patula 'Miss Kim')

Lilac Fasciation (crested growth form)

Many Types of Lilacs at the Arboretum

Flowering Plant Video Library - Shade Plants

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Great White Trillium, Trillium grandiflorum

Karl Foord

Photo 1: Great White Trillium (Trillium grandiflorum)

False Solomon's Seal (Maianthemum racemosum, syn. Smilacina racemosa)

Karl Foord

Photo 2: False Solomon's Seal (Maianthemum racemosum)


Lungwort, (Pulmonaria officinalis)

Karl Foord

Photo 3: Lungwort (Pulmonaria officinalis


Heucherella 'Stoplight' (Hybrid of Heuchera and Tiarella)

Karl Foord

Photo 4: Heucherella 'Stoplight'


Foam Flower, Tiarella 'Sugar and Spice' and Lungwort, Pulmonaria 'Trevi Fountain'

Karl Foord

Photo 5: Foam Flower (Tiarella 'Sugar and Spice')

Jacob's Ladder, Polemonium reptans 'Stairway to Heaven'

Karl Foord

Photo 6: Jacob's Ladder (Polemonium reptans 'Stairway to Heaven')

Lenten Rose, Helleborus orientalis

Flowering Plant Video Library - Spring Ephemerals

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Trout Lily (Erythronium americanum)

Karl Foord

Photo 1: Trout Lily (Erythronium americanum)

Virginia Bluebells (Mertensia virginica)

Karl Foord

Photo 2: Virginia Bluebells (Mertensia virginica) flower

False Rue Anemone (Enemion biternatum)

Karl Foord

Photo 3: False Rue Anemone (Enemion biternatum)

Minnesota Dwarf Trout Lily (Erythronium propullans)

Downy Mildew on Impatiens

Michelle Grabowski, UMN Extension

M. Grabowski, UMN Extension

Photo 1: Symptoms of Impatiens Downy Mildew

If you grew impatiens last summer, you may have noticed that some plants were stunted, turned yellow, and soon became barren stalks with perhaps one or two small yellow leaves clinging to them. These symptoms are caused by downy mildew, a disease caused by the water mold Plasmopara obducens. Had you turned a leaf over, you would have seen a fluffy white fungal 'down' covering the lower surface of the leaf.


Downy mildew of impatiens has been observed in the United States since 2004, but became widespread and highly destructive in 2011. Cool wet weather likely contributed to the disease epidemic of 2011 since the downy mildew pathogen thrives under these conditions.

Plasmopara obducens produces tough survival spores called oospores that can overwinter in soil and plant debris. As a result if downy mildew was present in your garden last year, it is likely to show up again in 2012. Downy mildew can also move in on wind blown spores. Although it is not known how far the downy mildew pathogen can travel by wind, a close relative, downy mildew of cucurbits, has been shown to move over 600 miles in 48 hrs. Plasmopara obducens does not move on seed, but it could move into a garden on infected transplants. Inspect all new impatiens for yellowing of leaves, stunting and white fluffy growth on the lower leaf surface. Nurseries producing impatiens are well aware of the threat of downy mildew and are scouting regularly to find and control the pathogen.

M. Grabowski, UMN Extension

Photo 2: Downy like growth on the lower surface of an infected impatiens leaf

Once the impatiens are in the ground for 2012, inspect the plants weekly for symptoms of downy mildew. Yellowing and stunting of the plants are typically the first symptoms observed. Downy white growth on the lower leaf surface confirms the disease. If downy mildew shows up, promptly bag and remove infected plants to reduce spread to neighboring plants. Space plants to allow air movement between plants. This will help reduce humidity and leaf moisture. If beds were infected in 2011, consider choosing a different annual plant this year. Downy mildew of impatiens only infects Impatiens walleriana, the standard impatiens. New Guinea impatiens, impatiens hawkerii are highly tolerant of the disease. No other plants are infected by this pathogen, so Begonias, Caladiums and other shade tolerant ornamentals are good choices as well.

Plant Video Library - Early Spring Bloomers I

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

American Pasqueflower (Anemone patens) and Prairie Smoke (Geum triflorum)

Karl Foord

Photo 1: American Pasqueflower (Anemone patens)

Karl Foord

Photo 2: Prairie Smoke (Geum triflorum)

Bloodroot (Sanguinaria canadensis)

Karl Foord

Photo 3: Bloodroot (Sanguinaria canadensis

Double Bloodroot (Sanguinaria canadensis 'Multiplex')

Karl Foord

Photo 4: Double Bloodroot (Sanguinaria canadensis 'Multiplex'

Marsh Marigold (Caltha palustris)

Karl Foord

Photo 5: Marsh Marigold (Caltha palustris)

Wild Ginger (Asarum canadense)

Karl Foord

Photo 6: Wild Ginger (Asarum canadense)

Plant Video Library - Early Spring Bloomers II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Pigsqueak (Bergenia cordifolia)



Karl Foord


Photo 1: Pigsqueak (Bergenia cordifolia)



Lenten Rose (Helleborus orientalis 'Ivory Prince')


Karl Foord


Photo 2: Lenten Rose (Helleborus orientalis 'Ivory Prince')


Bleeding Heart (Dicentra spectabilis 'Gold Heart')

Karl Foord

Photo 3: Bleeding Heart (Dicentra spectabilis 'Gold Heart')

Plant Video Library - Bulbs I

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Glory of the Snow (Chionodoxa luciliae)

Karl Foord

Photo 1: Glory of the Snow ( Chionodoxa luciliae) flower close-up

Checkered Lily (Fritillaria meleagris)

Karl Foord

Photo 2: Checkered Lily (Fritillaria meleagris) flower

Species Tulips (Tulipa tarda)

Karl Foord

Photo 3: Species Tulips (Tulipa tarda)

Garden Hyacinth (Hyacinthus orientalis)

Karl Foord

Photo 4: Garden Hyacinth (Hyacinthus orientalis)

Autumn Lily (Lycoris squamigera)

Flowering Plant Video Library - Bulbs II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture


Triumph Tulip (Tulipa 'Gavota)

Karl Foord

Photo 1: Triumph Tulip (Tulipa 'Gavota')

Grape Hyacinth (Muscari armeniacum)



Karl Foord


Photo 2: Grape Hyacinth (Muscari armeniacum)



Daffodils (Narcissus)


Karl Foord


Photo 3: Daffodils (Narcissus"Saint Keverne')


Dwarf Bearded Iris (Iris 'Joyce McBride)

Plant Video Library - Groundcovers or Lawn Substitutes

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Barrenwort (Epimedium x rubrum)

Periwinkle (Vinca minor 'Dart's Blue')

Pennsylvania Sedge (Carex pensylvanica)

Flowering Plant Video Library - Trees and Shrubs I

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Sungold and Moongold Apricots (Prunus armeniaca mandshurica 'Sungold' & 'Moongold'

Karl Foord

Photo 1: Apricot Flower (Prunus armeniaca)

Karl Foord

Photo 2: Young Apricot Fruit (Prunus armeniaca)

Regent Serviceberry (Amelanchier alnifolia 'Regent'

Karl Foord

Photo 3: Regent Serviceberry (Amelanchier alnifolia 'Regent'

Northern Strain Redbud (Cersis canadensis 'Northern Strain')

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Karl Foord

Photo 4: Northern Strain Redbud (Cersis canadensis 'Northern Strain')

Emerald Triumph Viburnum (Viburnum 'Emerald Triumph')

Flowering Plant Video Library - Trees and Shrubs II

Karl Foord - Extension Educator, Horticulture

Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture

Acrocona Norway Spruce (Picea abies 'Acrocona')

Karl Foord

Photo 1: Acrocona Norway Spruce (Picea abies 'Acrocona')

Clove Currant (Ribes odoratum)

Karl Foord

Photo 2: Clove Currant (Ribes odoratum) flower

Flowering Crabapple (Malus hybrida 'Indian Summer')

Frost Protection of Blueberry Flowers

Karl Foord - Extension Educator, Horticulture

Irrigation serves to protect blueberry flowers from frost damage.

Here are some pictures - explainations to follow:

Brad Munsterteiger

Photo 1: Frost protection of blueberry flowers by irrigation

Brad Munsterteiger

Photo 2: Frost protection of blueberry flowers by irrigation

Brad Munsterteiger

Photo 3: Frost protection of blueberry flowers by irrigation

Flowering Plant Video Library

Karl Foord - Extension Educator, Horticulture

This is the beginning of a flowering plant video library. The goal of this library is to give a short, guided, visual, one to two minute introduction to flowering plants that thrive under Minnesota conditions. You will be able to see the plant in a natural or landscape setting and see how it might fit into your landscape.

We will begin with three early flowering bulbs Snowdrops, Striped Squill, and Siberian Squill. The library will continue to grow and we hope that you will find video to be an enjoyable way to learn about and experience flowering plants.


Striped squill (Puschkinia scilloides var. libanotica)


Snowdrops (Galanthus nivalis)


Siberian Squill (Scilla siberica)

Early Found Fragrances - Olfactory Delights at the Minnesota Arboretum!

Karl Foord - Extension Educator, Horticulture

While exploring the Minnesota Landscape Arboretum I encountered Dr. Stan Hokanson the woody plant breeder in the Department of Horticulture Science. He introduced me to the Clove Currant (Ribes odoratum). The odoratum nomenclature is well deserved. Clove Currant give off a very pleasant spicy fragrance hinting of clove and alspice (Photos 1 and 2). The plant has yellow flowers and a corolla long enough to restrict its pollinators to those with long tongues like bumblebees (Photos 3 and 4).

Another tree with fragrant flowers is the Korean crabapple (Malus bacatta jackii) one of the earlier flowering crabapples. The flowers are being visited by native bees (Photos 5 and 6).

Karl Foord

Photo 1: Clove Currant (Ribes odoratum) flower close-up

Karl Foord

Photo 2: Clove Currant (Ribes odoratum) flower

Karl Foord

Photo 3: Bumblebee showing long tongue required to reach nectaries on Clove Currant

Karl Foord

Photo 4: Bumblebee pollinating Clove Currant

Karl Foord

Photo 5: Native bee (Andrena ssp.) on Korean crabapple (Malus baccata jackii)

Karl Foord

Photo 5: Native bee on Korean crabapple (Malus baccata jackii)

Frost Damage to Apple Flowers

Karl Foord, Extension Educator, Horticulture

Temperatures in the mid to low 20's were encountered last Tuesday April 10th in many parts of central and southern Minnesota. Apple fruit flowers are damaged at temperatures lower than 28 degrees F. depending on the stage of the flower bud and the length of time at the low temperature. The more open the flower bud the more susceptible the bud is to low temperature damage.

The following picture gallery shows the types of frost damage experience by apple flowers in Chaska, Minnesota. The gallery begins with heathy flowers with green stigmas and cream anthers, shows partially damaged flowers with dead stigmas and soom dead anthers, and finally a flower will all parts killed.

Karl Foord

Photo 1: Healthy Apple Flower

Karl Foord

Photo 2: Healthy or partically damaged apple flower

Karl Foord

Photo 3: Totally damaged flower top left and partially damaged flower bottom right

Karl Foord

Photo 4: Frost killed apple flower with brown stigmas and anthers

Karl Foord

Photo 5: Frost killed apple flower with brown stigmas and anthers

What Bulbs are Flowering at the Minnesota Landscape Arboretum?

Karl Foord, Extension Educator - Horticulture

Bulbs

Click any image below to open a slideshow.

What Trees are Flowering at the Minnesota Landscape Arboretum?

Karl Foord, Extension Educator - Horticulture

Click any image below to open a slideshow.
Trees

Many tree flowers are described as inconspicuous. This may be more a matter of size and location. Tree flowers tend to be shhort lived, inaccessible if higher up in the tree, and smaller than many of our showy garden flowers. On closer iinspection you may find them to be rather intreguing. Consider the first photo of Autumn blaze Maple.

A Range of Colors - Pollen

Karl Foord, Extension Educator, Horticulture

I was photographing honeybees working an early pollen source last spring - Allium Allium christophii 'Star of Persia' (Photo 1).



Karl Foord


Photo 1: Honeybee on Allium christophii 'Star of Persia'


I noticed that the pollen carried by the honeybee was an interesting grey color. This led me to wonder about pollen colors. I did some research and came up with a dizzying array of pollen colors represented in Table 1).

Karl Foord

Table 1: Chart of Pollen Color of Some Selected Plants

Photo 2 shows a bumblebee with the off white pollen of Sedum.

Karl Foord

Photo 2: Bumblebee on Showy Snowcrop Sedum sieboldii 'Star of Persia'

As spring approaches keep an eye out for the array of pollen colors offered by our spring flowers (Photo 3) and carried by our insect pollinators (Photo 4).

Karl Foord

Photo 3: Scilla siberica Siberian Squill with blue pollen

Karl Foord

Photo 4: Honeybee working Scilla showing corbicula or pollen basket with blue Scilla pollen

Watering orchids - roots tell the story

Karl Foord - University of Minnesota Extension

It is not often that a plant can through a visual color change indicate its need for water, however the aerial roots of tropical epiphytic orchids indeed do. Epiphytes are plants that grow on other plants or structures but are not parasitic (Photo 1).



lifeamongtheleaves.blogspot.com/2009/10/pictu...


Photo 1: Epiphytes on Tree



They derive their moisture and nutrients from air, rain and nearby debris. Most of the orchids used as house plants are tropical epiphytes.
The roots of these plants not only serve to anchor the plant to trees or stone, they also function as water storage units capturing water during rain events. The roots have a unique structure that enables them to absorb and store water. Phil Gates, a botanist at Durham University in the UK, has a blog entitled, Beyond the Human Eye - An insight into a microscopic world, invisible to the unaided human eye. He has sectioned and photographed an orchid root (Photo 2).



Phil Gates


Photo 2: Sectioned orchid root



The xylem vessels that conduct water from the roots to the leaves consist of the ring of bright yellow cells at the bottom of the photograph. Surrounding the xylem vessels is a layer of blue packing cells. Exterior to the packing cells is a row of hexagonal cells beyond which are a layer of dead cells called the velamen layer. The velamen layer functions as a sponge soaking up water as the aerial roots are exposed to rain or mist. Interestingly the velamen layer changes color based on water content and is an excellent indicator of the plant's water status. Dry velamen reflects light and is white or silvery (Photo 3),



Phil Gates


Photo 3: Dry orchid root



but when the velamen absorbs water the green tissue underneath becomes visible and the root takes on a green or mottled green color depending on the species (Photo 4).



Phil Gates


Photo 4: Wet orchid roots



A Look at the New USDA Hardiness Zone Map

A hardiness zone map (HZM) provides information that gardeners and professional horticulturalists use in determining which herbaceous and woody perennial plants will survive cold temperature in a particular geographic area. Last week the United States Department of Agriculture released a new hardiness zone map to replace the older 1990 version.

As with past maps, the new map:
  • is a visual representation of average annual minimum temperatures across the United States. Data points used to create the map were the lowest daily minimum temperatures recorded at thousands of temperature data stations during each of the years sampled.
  • divides the U.S. into multiple hardiness zones with 10o F differences in average annual minimum temperatures. Zone 1 is the coldest zone (-50o F to -60o F).
  • divides each hardiness zone into "a" & "b" with "a" being the colder half of any zone and "b" the warmer half.

There are changes in the new map and the process that was used to develop it:


    IUSDA


    Photo 1: 1990 USDA Hardiness Zone Map



  • The 1990 HZM was based on data from a 12-year period (1976-1990) while the new HZM is based on data from a 30-year period (1976-2005).
  • The data used to create the new map was more complete, and a complex algorithm was used to interpolate between recording stations. Temperature data from more than 8000 temperature data stations belonging to the National Weather Service, the USDA Natural Resources Conservation Service, the USDA Forest Service, the Bureau of Reclamation, and the Bureau of Land Management was used. Average minimum temperatures were then calculated for ½ mile square computer grids for the entire country to create the new hardiness zone map. This was followed by a review process that included climatologists, agricultural meteorologists, and horticultural experts who checked for errors, looked for the source of errors, and corrected errors.


    USDA


    Photo 2: 2012 USDA Hardiness Zone Map



  • The new map is Geographic Information System-based. This means that the map is more accurate, is interactive (by zip code) to improve user experiences, and has higher resolution that can show smaller areas of zone delineations than before. While the 1990 map was a static image and was not designed for web use, the new map allows users to zoom in to a local area to see the higher temperatures of cities that are heat sinks, the lower temperatures on mountain tops, and the buffering effects of large bodies of water on temperature.

What does the new hardiness zone map show?
In general, the new map shows what we have all been experiencing in recent history: warmer low temperatures during winter. A shift of ½ of a zone was common for much of the country. Closer to home, here is what happened to Minnesota's hardiness zone map:



    USDA


    Photo 3: 1990 USDA MN Hardiness Zone Map




    USDA


    Photo 4: 2012 MN Hardiness Zone Map


  • There was a ½ zone shift for much of the state because Minnesota, like the rest of the U.S., has been experiencing warmer annual minimum temperatures during the time period used to create the new HZM.
  • Zone 5a (with average minimum temperatures of -15o to -20o) crept up into the south central portion and the far southeastern corner of Minnesota.
  • Much of the southern ½ of Minnesota that was formerly divided into zones 4a & 4b is now zone 4b (with average minimum temperatures of -20o to -25o).
  • The four pockets of Zone 2b (with average minimum temperatures of -40oto -45o) disappeared from northern Minnesota.
  • The amount of Minnesota that is zone 3a (with average minimum temperatures of -35o to -40o) shrank significantly due to an increasing area of zone 3b (with average minimum temperatures of -30o to -35o).
  • Parts of the far northern shore of Lake Superior that were formerly zones 4b and 4a are now designated as 4a and 3b, meaning they are colder.

What kind of impact should the new hardiness map have on Minnesota gardeners?

  • We can all rest easy knowing that the warmer minimum annual temperatures we have been enjoying over the past years really did happen!
  • Remember that a HZM is created based on average annual minimum temperatures and should only be used as a general guide. By the very definition of average, we know that temperatures lower than the average minimum temperature of the zone you live in will occur. Pick your plants accordingly. Maybe we can broaden the palette of plants we choose to grow in Minnesota a bit, but be cautious and wise in your weighing of risk vs. gain as you trial new plants. Losing an herbaceous perennial or quickly-maturing shrub to winter injury may be of little concern in terms of the time it takes to establish a replacement plant. Losing a slow-growing shrub or a tree that takes decades to grow to mature size creates more pain.
  • Hardiness zone maps are of no help in predicting plant damage or mortality during acclimation and deacclimation. Remember that hardiness is not just about the lowest temperature a plant must survive during a winter. Every year, starting in late summer, perennial plants goes through a multi-month process called acclimation that prepares them for winter survival. In spring dormant plants go through a reverse process called deacclimation that restores their ability to actively grow during the growing season. Plants can be winter-injured or killed by abnormally low temperatures during the months of acclimation and deacclimation too. This is especially true of marginally hardy plants from warmer parts of the country or world that we may try to grow in Minnesota.
  • Hardiness zone maps provide gardeners with one category of plant performance information: winter survival. Good plant performance is not just about winter survival. If the new HZM persuades you to plant cultivars and species new to you, remember that there are other selection categories to consider as you match a plant to your planting site: soil texture, soil moisture, soil pH, light exposure, precipitation, etc.

Preserving the Harvest: Growing Everlastings in your Cutting Garden

Robin Trott, UMN Extension Educator, Douglas County

Robin Trott

Helichrysum (strawflower).

My house has been full of beautiful floral arrangements all summer, and the fall arrangements are outstanding, however, we will soon enter the cold months, and I can't envision a house without the color from my garden. To avoid this, I have made sure to include some everlasting plants in my cutting garden: Limonium sinuata (Statice), Helichrysum (Strawflower), Gomphrena, Achillea (Yarrow), Celosia (Cockscomb), and ornamental Grasses are all good candidates for air-drying. Once dried, I use these everlastings in bouquets, sachets, wreaths and holiday crafts.

Robin Trott

Echinacea (purple coneflower).

Harvest your everlastings when the flowers are not fully open and in good condition. Don't wait too long, because flowers too far along will not dry satisfactorily. Select flowers or seed pods that are as close to perfect looking as possible because flaws, such as insect damage, become more obvious once they are dried. Pick your flowers in the late afternoon, after the heat of the day has passed and before the evening dew has set in. Using a sharp, clean tool, cut flowers close to the base of the plant (to keep stems as long as possible) and remove foliage from the stem to preserve the best color and shape. Group stems together in small bunches so the flower heads do not touch, secure with a rubber band or string and hang upside down in a warm, dry, dark area. Your garage, attic, spare room, garden shed or even a closet will do. With good air circulation, flowers take 1 to 3 weeks to dry completely. Store dried flowers in an airtight container until ready to use. Dried plant material can be stored in cardboard boxes; however, plants are better protected from insects and rodents if they are stored in airtight containers.

Robin Trott

Celosia spicata.

If you have never tried to dry your flowers, and are not sure what to include in your cutting garden, try some of these flowers and seed heads that lend themselves to air drying:

Achillea Spp. (Yarrow) - perennial
Ascelpias (Butterfly Weed) - perennial, primarily for seed pods
Astilbe - perennial
Artemisia annua (Sweet Annie) - self seeding annual
Calendula (Pot Marigold) - annual
Celosia - annual
Centaurea cyanus (Bachelor's Buttons) - annual
Echinacea (Purple Cone Flower) - perennial primarily for cones
Eryngium (Sea Holly) - perennial
Helichrysum (Straw Flower) - annual
Hydrangea- woody perennial
Gaillardia (Blanket Flower) - annual
Echinops (Globe Thistle) - perennial
Gomphrena- annual
Physalis alkekengi (chinese lantern)
Grains (Oats, Wheat, Millet)
Ornamental Grasses
Gypsophila (baby's breath) - perennial
Limonium (statice) - annual
Lunaria annua (Money Plant, Honesty) - annual
Nigella damascena (Love in a mist) - annual, primarily for seed pods
Rudbeckia (Black Eyed Susan) - perennial, primarily for cones
Solidago (Goldenrod) - perennial

Good luck with all your everlasting adventures!

The Garden Blues

Samantha Lahman, University of Minnesota Extension Horticulture Intern, Douglas County

Centaurea cyanus, more commonly known as the annual Bachelor Button or Cornflower, is in full bloom in the garden this summer. Cornflowers are easy to grow and come in a great variety of colors, which has made them a long time favorite for novice and experienced gardeners. The Cornflower received its common name from the flowers that bloom wildly in the grain fields of southern Europe. It is even rumored that the Cornflower was selected as Germany's National Symbol of Unity because Queen Louise of Prussia; upon fleeing Germany to escape Napoleon, reportedly hid her children in a cornfield and kept them quiet by weaving Cornflowers into wreaths.

Samantha Lahman

Cornflowers are tall annuals that grow on beautiful grey-green stems. The most common color is a bright blue (Blue Boy), but other varieties range from pinkish white to deep maroon. Growing to a height of 24-36 inches, they can be easily placed in gardens of any size and are beautiful fillers along borders. They are also useful in cut flower gardens and are commonly included as dried flowers in everlasting arrangements. For an unusual twist, use their edible blooms to add color to salads and other dishes. Along with their aesthetic and tasteful qualities, Cornflowers are often used to attract bees, butterflies, and birds.

Cornflowers have become such a staple due to their prolific nature. Even the most inexperienced gardeners can grow them successfully. These plants thrive in full sun, but can also grow in partial shade. They prefer moist, well drained soils and will grow well in soil pH levels ranging from 6.6 to 7.8. They are also moderately cold tolerant and can endure temperatures that reach into the low 40s.

Cornflowers are most commonly grown from seed. Sow cornflowers in the spring, approximately 1 to 2 weeks before the last frost. Planting at this time will give you early spring blooms. Germination can be expected in 7 to 10 days. Seeds should be sown 1/4" deep and placed 1" apart .For earlier blooms, start seeds indoors about one month prior to the frost free date. When starting your seeds indoors sow 3 to 4 seeds per pot and cover the seeds with a 1/2" layer of the mix because centaureas need darkness to germinate. Cover your pots with plastic wrap, or a clear plastic dome to retain soil moisture and humidity. When seedlings emerge, remove the plastic covering to avoid overheating and leaf burn. Once your cornflowers are approximately 2 inches tall, transplant outside in your chosen garden location. For optimum success, transplant your seedlings on a calm, overcast day. While these plants are known to be tough, it is easier on the plants if they aren't immediately exposed to excessive heat and damaging winds. Remember to water immediately following transplanting. When seedlings are 1 to 2 inches tall, thin to 6 to 8 inches apart. Cornflowers bloom for approximately one month. If you wish to have an extended blooming season, consider successive plantings. Planting every two weeks will insure that your blooms last the summer.

Samantha Lahman

After they are established, watering should be done infrequently. Yes, infrequently. Another charming quality of cornflowers is that they are extremely drought tolerant. When over watered, the cornflower's stems will become droopy and soft. As with most flowers, remember to trim dead and expiring blooms to encourage the growth of new blooms. Cornflowers are generally pest resistant. The most common pest to invade Cornflowers is the aphid. To control aphids, you can spray them off with a garden hose or apply an insecticidal soap. These little flowers are also very resistant to diseases and fungi. Extremely wet weather leads to fungal problems such as: rust and powdery mildew. To help prevent fungal infections, water at the base of the flowers so as not to get the leaves wet, and remove any leaves or stems that you suspect are infected. Use fungicidal soap or garden sulfur to control rust on plants.

Before investing your area of garden to cornflowers forever, by planting centaurea Montana, the perennial version of centaurea, take into consideration that while Centaurea cyanus is an annual, this does not mean that you will need to replant year after year. Many times cornflowers will re-seed. To encourage this natural re-seeding, leave the last blooms of the growing season on the plants.

I adore blue in the garden, and am always looking for new and unusual "blues" to add. However, my staple "blue" is the prolific cornflower. If you also love "the blues", and are looking for attractive, multi-use blossoms, cornflowers are the way to go.

"The blues tells a story. Every line of the blues has a meaning."
John Lee Hooker

Samantha Lahman is the 2011 Summer Intern for the Horticulture Extension in Douglas County. This summer she has been busy writing the "Growing Green" newspaper column for local newspapers, diagnosing plant problems, identifying bugs, updating the West Central Gardener Facebook page, and creating a workshop for the Douglas County Master Gardeners to use in the future on "Growing Your Own Meadow Garden." Samantha will be a senior this year at the University of Minnesota, Crookston. Her major is Animal Science with minors in Communication and Agricultural Business. After college she hopes to work either for the U of M Extension in the 4-H and Youth Development areas or Public Relations for one of the Minnesota livestock associations.

Lilies - One of the Queens of the Garden

Karl Foord

Lilium 'Heart's Desire' Asiatic Lily. To see more photos, please view: Lilies Photo Essay.pdf.

Karl Foord, UMN Extension Educator

When entering the world of lilies for the first time, one is dazzled by the large spectacular flowers with variations in color, texture, size, fragrance, petal shape, and flower orientation. This variation is a function of: 1. species groups, such as Asiatic and Oriental designations, 2. single species, such as Lilium longiflorum (the Easter lily), and L. regale (the Trumpet lily), and 3. hybridizations between the above such as Oriental x Trumpet identified as Orienpet or OT hybrids, and Longiflorum x Asiatic identified as LA Hybrids (LA). Although this is still a simplification, it seems like a good place to start.

Cultivars derived from the latter crosses are selected for the best qualities of each species. The result is a hardier more garden persistent heat tolerant plant with sublime beauty. The lily collection at the Minnesota Landscape Arboretum contains predominantly Asiatic, OT, and LA hybrids.

This photo essay is a small sampling of these types of lilies. Regardless of your present knowledge and experience of lilies, there seems to be plenty of room for further exploration of this genus. Click here to view the photo essay: Lilies Photo Essay.pdf

Previous Y&G articles addressing lily issues can be found at:
Selecting Lilies for Your Garden

New Lily Classes Grow in Availability and Popularity


Further information can be found through the North American Lily Society and the regional Minnesota affiliate.

Flowers - Beautiful, Nutritious, & Dangerous

Karl Foord

Photo 1: Goldenrod Spider "Flower Spider" "Red-spotted Crab Spider Misumena vatia; Male on top of female who has Spring azure Blue Butterfly Celastrina sp. in grasp

Karl Foord, UMN Extension Educator

While photographing lilies for the article "Lilies - One of the Queens of the Garden," I came upon a blue butterfly (perhaps a Spring Azure Celastrina sp.). I was hoping to photograph it when it had opened its wings. I slowly drew closer only to realize that it was not to open its wings again. It was in the grasp of a flower spider (perhaps a Goldenrod Spider or "Red-spotted Crab Spider" Misumena vatia).

A smaller spider perhaps a male of the species jumped on top of the other spider and then fled. I would expect this was a wise thing to do. This spider was particularly well camouflaged on this Lilium 'Heart's Desire' Asiatic Lily. Flowers are beautiful, nutritious and dangerous, depending on your point of view.

Karl Foord

Unusual Rudbeckia for your Garden

Robin Trott

Photo 1: 'Cherokee Sunset' rudbeckia.

Robin Trott, UMN Extension Educator

In a few weeks our ditches and roadsides will be full of those yellow daisies known as Black-eyed Susans or rudbeckia. A native wildflower and perennial favorite, rudbeckias are reliable plants that fill our gardens with brightly colored flowers from July through the first frost. They are easy to grow, adapt to a wide variety of soil conditions, have very few insect or disease problems, and bloom the first year when started from seed. However, they weren't always a staple of American gardens.

In the early 17th century, British plant collector, John Tradescant, collected roots from French settlers in the "New World". The plant was shared with other botanists and herbalists, and was soon popular in English Gardens. By the mid-1800's, it found its way into American gardens and was noted by an early garden writer as "the darling of the ladies who are partial to yellow." It was used medicinally by Native Americans to treat both people and horses. The roots and flowers were made into teas and compresses to treat a variety of ailments, including: snake bites, worms, earaches, indigestion, burns and sores.

Robin Trott

Photo 2: 'Cherry Brandy' rudbeckia.

Robin Trott

Photo 3: 'Autumn Colors' rudbeckia.

There are 25 species of Rudbeckia including perennials, biennials and annuals. A member of the Aster family, Rudbeckia's flowers come in single- semi-double and full double forms, and range from lemon-yellow to gold, chestnut, mahogany and bronze as well as multi-colored blooms. If you have never planted Rudbeckia, I encourage you to try some this year. They were stellar performers in our garden last year, and many marginally hardy varieties made it through our snowy winter, and are beginning to bud out. Some varieties I have successfully grown are:

Rudbeckia fulgida is perennial to zone 3. 'Goldsturm' is a 2'-3' tall plant that is long-lived and reliably produces abundant blooms from midsummer to frost. It was voted the Perennial Plant of the year in 1999.

Rudbeckia triloba, the brown-eyed Susan, is hardy to zone 4. Plants are 2'-5' tall, and the flowers are yellow with black centers that fade to brown.

The largest group of rudbeckias is Rudbeckia hirta, or gloriosa daisies. These are short-lived perennials, and are grown as annuals in our northern climate. They readily self seed, and are some of the most colorful Rudbeckia available.

  • 'Indian Summer' was an All-American Selections winner in 1995. It produces giant 5"-9" flowers on 3' tall plants. The golden petals are wider than the wild variety, and the flowers make long lasting cuts.
  • 'Cherokee Sunset' is a semi-double and double flower, with 2-4" blossoms in shades of yellow, orange, bronze and mahogany. These 2' tall plants are spectacular in the garden and in mixed fall bouquets.
  • 'Cherry Brandy' is a 24" single flowering variety. Its long-lasting 4" blooms are cherry red at the tips darkening to deep maroon at the center. This "Susan" has the typical "black eye".
  • 'Autumn Colors' is an upright compact plant just 20 to 24 inches tall and 15 inches wide. The Single and Semi-double, 5-7" flowers are a vibrant mix of oranges with deep brown and orange markings.


Rudbeckia make excellent cut flowers, with a vase life up to 21 days. Harvest rudbeckia when the flowers are fully open, during the coolest part of the day, and place in clean, warm water. Re-cut stems under water, removing about one inch, to eliminate air bubbles and bacteria. Create your floral design and place bouquet in water containing floral preservative.

Rudbeckia are ethylene sensitive. Ethylene is an odorless, colorless gaseous plant hormone that exists in nature and is also created by man-made sources. It can be produced by ripening produce, propane heaters, auto exhaust, cigarette smoke, other flowers and fungi. For longest vase life, keep your floral bouquets away from ethylene producers.

Visit your local garden center, or consider purchasing seed next year for beautiful Rudbeckias in your home garden. Whichever you choose, you won't be disappointed.

Unusual Bouquet Fillers for your Cutting Garden


Minnesota gardeners struggle to balance a short growing season with a diverse garden. Many beautiful floral varieties just don't work in our Zone 4 (with pockets of zone 3) environment. This means that we have to rely heavily on annuals for our cut flower gardens. Zinnias and sunflowers provide bright color; annual rudbeckia, helichrysum and snapdragons make wonderful focal flowers in any bouquet; but what to grow for interesting filler? Baby's breath is an option, but is overused, and readily available at your local florist. I tend to look for something unique, fragrant and maybe a little quirky to give my arrangements that unexpected touch that sets them apart from other bouquets. I grow herbs, grasses and smaller flowers to complete my floral arrangements.

Limonium sinuatum (statice) has paper-like bracts that later bloom with delicate white flowers. Once Statice starts blooming it continues to bloom until frost. When harvesting, cut the flower stalks back to the rosette leaves at the base of the plant.

field-blue-ageratum

Robin Trott

Photo 2: Ageratum "blue sensation".

Limonium needs no special post harvest care, and doesn't fade as it dries. Achillea millefolium (Yarrow) is perennial to zone 3, which makes it a great choice for our harsh Minnesota winters. It ranges in color from deep red, orange, purples, pinks to clear white; and blooms early summer to frost. Its silver-green lacy foliage is fragrant, and can also be used to enhance your arrangements.

Harvest when all florets are open, place in floral preservative, and store in a cool place. Ageratum houstonianum 'Blue Sensation' features fluffy lavender flowers in flattened to slightly rounded clusters on strong upright (18-30") stems. 30" Gomphrena haageana has brightly colored bunny tails that add whimsy to your bouquets (try cherry red Strawberry Fields, bright pink Fireworks or QIS mix), and contrasts nicely with Celosia's bright spikes. (Try Celosia spicata "Flamingo Feather".) Ageratum, Gomphrena and Celosia produce flowers from summer to early fall and are great for cutting and drying. Gomphrena is fairly drought tolerant

strawberry-fields-gomphrena

Robin Trott

Photo 3: 'Strawberry Fields' Gomphrena.

Herbs provide fragrance to otherwise unscented bouquets. Basils, such as Sweet Dani, Purple Ruffles and Red Cardinal are long lasting, fragrant and edible. Cardinal Basil plants are well branched, so you will be able to take a number of cuts per plant. Its dark green leaves are topped with maroon rosettes that make it both unusual and tasty. Super hardy mints, such as Lemon Balm, Spearmint and Peppermint, provide colorful greenery and can later be used to flavor teas, and summer beverages. Mint can be somewhat invasive, so keep this in mind before adding it to your garden space. Perovskia atriplicifolia Taiga, (Russian Sage) boasts tall blue flower spikes and silver green foliage.

Robin Trott


Photo 4: Blooming cilantro.


Deep-rooted, heat loving and drought tolerant, it's not picky about soils, and thrives in almost any location. Cilantro, a popular herb widely used in Mexican, Caribbean and Asian cuisine, features delicate foliage and tiny white flowers. One of my favorites, Artemisia annua (Sweet Annie), has abundant, lacy, fragrant foliage. A tall (36"-48") woody herb, Sweet Annie can be cut and placed in cool water, or dried and used to make fragrant autumn wreaths.

For something completely different, include tall grasses, wheat or ornamental eggplant to highlight your fall displays. Perennial grasses, such as Karl Forester, and annuals like millet can complement the fall colors of rudbeckia and wine zinnias. Dried Black tipped wheat, available as seed from a variety of garden catalogs, can be used in fresh or dried bouquets. My absolute favorite, Solanum integrifolium, also known as Pumpkin on a stick, really adds something special to your fall bouquets. The plants are quite thorny, so be careful when harvesting. Cut near the base of the plant, remove the foliage, and use in fresh bouquets, or dry in a cool, well-ventilated location, and use in your dried arrangements. (If you find you have extras, they are edible, and can be used in traditional Asian Stir Fry recipes.)

The keys to successful floral arrangements are color, texture, and imagination. Don't get stuck on the same old, same old. Try something new and different this year. Bring the pleasure of your garden into every room in your house with long lasting floral arrangements chock full of herbs, greens and colorful flowers.

Earth laughs in flowers. ~ Ralph Waldo Emerson

I never met a beard I didn't like - on an iris, that is!

Karl Foord, UMN Extension Educator

I took a closer look at bearded irises this past week and two things intrigued me.
The first thing that intrigued me was the amazing variation in iris petal and beard colors (photos 1-4). It was also interesting to observe the change in beard colors throughout their length as they moved from the exterior part of the petal to the interior part of the flower (photos 5-7).

The second was a question of how did this flower actually work given the very obvious and showy petals and the less obvious male stamens and female pistils. The iris flower has a unique structure whose purpose is to avoid having pollen from this flower's male stamens transferred to the same flower's female stigmatic surface and pistil. As the bee enters the flower tracking along the beard it passes a flap that the insect will push past and fold back exposing the moist receiving part of the stigmatic surface capturing pollen on the hairy back of the insect. As the bee continues toward the nectarines and sugar reward it then passes under the anther picking up pollen on its back. When it has finished feeding on the nectar and begins backing out of the flower, the stigmatic fold is pushed the other way exposing a dry non-receiving part of the stigma and thus transfers no pollen from this flowers anthers to the same flowers stigmatic surface (photo 8). Can you identify the same flower parts in photo 9?

The system is not foolproof, however, because the same insect could visit one of the two other parts of the same flower, or another flower on the same plant.

Note: all photos taken at the Minnesota Landscape Arboretum.




Growing Sunflowers for your Cutting Garden

Robin Trott, UMN Extension Educator

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Cherry Rose. Robin Trott.

The Sunflower, or Helianthus, is a very popular flower to include in an annual cutting garden. A native of North America, the sunflower comes in a variety of sizes, growing habits and colors, making it an ideal choice for the home gardener. From the Giant sunflowers like "Kong", to the multi branching "Italian White" to the petite "Teddy Bear", an 18" tall puff-ball; there is a sunflower to match every gardener's taste and purpose. One of my favorites from last year was a pollen-less variety called "Cherry Rose". This 6' tall, branching plant is covered with 5" lemon yellow blossoms with red overtones. Grown in full sun, the lemon color abounds, in a more shaded site; the dark plum color is dominant. Another excellent choice, "Ring of Fire", is a mid-height plant (4-5') with 5" blooms. This late bloomer boasts bi-colored petals with a dark red base and golden yellow tips surrounding a chocolate brown center. For the giant sunflower enthusiast, "Kong" is as big as it gets. Reaching 12 feet tall, "Kong" is even more impressive because it's multi-branched and covered with 4-6 inch yellow blooms offset by large, dark green leaves. The most versatile sunflower in my garden last year was the "Music Box". "Music Box" grows into a stocky, 2 ½' bush of abundant, multi-branching 4-5" golden, daisy like sunflowers. These petite, buttery IMG_0203.JPG

Ring of Fire. Robin Trott.

flowers were ideal in mixed fall bouquets, and bloomed prolifically until frost.

Keep in mind these cultural practices once you have selected your perfect sunflower variety.


  • Select a site that receives at least 6 hours of sun a day. (More is preferable)

  • Sunflowers prefer loose, well-drained, rich soil; so amend with compost if you have heavy clay or sandy soil.

  • Sow seeds directly into the garden once the soil has reached 50°. (Cooler than this will slow development.)


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Music Box. Robin Trott.



  • Plants seeds at a depth 2 times their width, and space close (6") to promote tall plants; and small, bouquet sized heads. This close spacing will soon shade out weed competition and mature plants will protect and support each other.

  • Sunflowers are heavy feeders, and should be fertilized. Side dress with a balanced fertilizer (10-10-10) every 21 days during the growing season.

  • Keep your sunflowers weed free. Weed competition reduces the quality of your sunflowers.


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Kong. Robin Trott.



  • Tall sunflower varieties will need support to protect them from wind damage. Stake them or grow them through horizontal support netting to ensure your plants remain standing after our typical summer "hazardous" weather.

Harvest your sunflowers during the coolest part of the day. The plants should be free of dew and moisture. Cut when petals begin to lift off the face, but are not completely open. Make sure your cutting tools and containers have been sterilized with a 5% bleach solution. Cut stems at least 24" long and at an angle for best results. Sunflowers prefer clean water to floral preservative. (Floral preservative can actually over-hydrate your flowers, making them wilt.) Place your cut sunflowers in a cool place as soon as possible after cutting. If wilting occurs, don't worry, leave them in water for 24 hours, and they should perk right up. Vase life for fresh cut sunflowers is 7 to 10 days, with pollen-less flowers having the longest vase lives.

Sunflowers are a colorful choice for your garden, make long lasting cut flowers, and provide food and habitat for wildlife. It's not too late to start them for this gardening season. Select your cheerful sunflower variety today, and get growing!

Until Next Time, Happy Gardening!
***
Bring me then the plant that points to those bright Lucidites swirling up from the earth, And life itself exhaling that central breath! Bring me the sunflower crazed with the love of light.
~ Eugenio Montale

Iris Show

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Photo 1: Iris cristata Crested Dwarf Iris. Karl Foord.

Karl Foord, UMN Extension Educator


Don't miss the Iris show that is coming into its own at this moment. The Iris genus contains some 260 species of plants with showy flowers. The most commonly found garden iris is the bearded German Iris (Iris germanica), and its many cultivars (Photo 1). Other beardless iris types found in the garden are the Siberian Iris (I. sibirica) and the Japanese Iris (I. ensata), and their respective hybrids. The Siberian Iris can be distinguished from the Japanese Iris as the latter's flower is a more upward facing flatter flower. A number of other species are worth considering including the Dwarf Crested Iris (I. cristata) (Photo 2).

We have two excellent publications on Iris as follows:
"Iris" by Rhonda Fleming Hayes and David C. Zlesak and
"Gardens" by Deborah L. Brown.

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Photo 2: The beard of a bearded iris, Iris germanica. Karl Foord.


Zinnias for Your Yard and Garden

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Photo 1: Benary's Giant Wine

Robin Trott, UMN Extension Educator


Last summer was the first year I grew zinnias in any quantity. Spaniards who first saw them growing in Mexico thought zinnias were so unattractive they called them "mal de ojos", or "sickness of the eyes"; and until last summer, I tended to agree. I thought zinnias were large, gaudy flowers that didn't even have the redeeming quality of a pleasant fragrance; and so I never grew them in my home garden. Boy, was I wrong!

Last summer I grew many tall zinnia varieties to be used as cut flowers. Benary's giants were spectacular, and the peppermint stick varieties were something else. It's no wonder that the National Garden Bureau has declared 2011 the "Year of the Zinnia."
One of the reasons for the booming popularity of the zinnia is its diversity. Zinnias have a variety of flower forms--they may be single, semi-double, or double. Single Zinnias, Zinnia angustifolia, have one row of petals with an exposed center, similar to the daisy. rt2.jpg

Photo 2: Benary's Lime

Crystal White, an All American Selections winner is a delightful example of the single flowering variety. The semi-double and double flowered zinnias have a mass of dense petals that hide the center. Button, beehive, cactus shaped and dahlia flowered zinnias all fall within this category. Profusion, Queen Red Lime and Zahara are all examples of premium double flowering zinnias. Giant Fantasy is a splendid cactus flowering zinnia, and, Benary's Giant is a spectacular dahlia flowering variety. Zinnias also come in a wide range of color choices. My favorites are the cream, salmon, magenta and lime varieties. If you have a specific color scheme in mind, there is a zinnia that will fit in your garden palette.

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Photo 3: Peppermint Stick

rt4.jpgZinnias are annuals that grow easily from seed. Direct seed after all danger of frost has past and the soil has warmed; or start inside 4-6 weeks before your last frost date (May 24 for our region.) Zinnias bloom profusely throughout the growing season and can grow as short as 6" or as tall as 48". Zinnias require minimal care. Deadhead spent blooms to encourage repeat blooming, keep watered during the growing season, and fertilize at half strength monthly from July - September. Zinnias are prone to powdery mildew, so avoid overhead watering, and space them to allow air flow between plants.


Use zinnias as border plants, in containers, as tall garden focal points, dried, and for cut flowers. Choose smaller varieties, such as Zinnita at the front of border plantings and in containers. Benary's Giant and tall cactus flowering zinnias are excellent as focal plantings and for cut flowers.

To gather flowers for fresh arrangements, cut them during the cool part of the day. (Early morning or early evening.) Select blooms that have not fully opened--they will continue to open indoors. Cut zinnias into a clean bucket of fresh water, and re-cut the stems, removing the lower leaves, before arranging them.

"Cultivators of the earth are the most valuable citizens. They are the most vigorous, the most independent, the most virtuous, and they are tied to their country and wedded to its liberty and interests by the most lasting bands." -Thomas Jefferson.

All photos by Laura Trott, taken in the garden of the author, Robin Trott.

Rose Classes and Their Performance in Minnesota: Part 1

Kathy Zuzek, UMN Extension Educator

The number of rose cultivars in the world defies logic. If you open a copy of Modern Roses 12, the most recent edition of the American Rose Society's rose cultivar list, you will find thousands of rose cultivars or varieties listed along with each rose's class, year of release, the breeder who developed the cultivar, parentage, and descriptions of each cultivar's floral and foliage traits, plant habit and thorns.

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Photo 1: Flower of R. acicularis, one of Minnesota's native roses. Kathy Zuzek.

Before cultivar selection and development, there were only the species or "wild" roses. There are 120 or more rose species in the world and they are found in the temperate and sub-tropical regions of the Northern Hemisphere: the Middle East, Oriental Asia, Europe, and America. The oldest species have single flowers with only 5 or occasionally 4 petals and bloom only once each year in spring. As mutations occurred in some rose species over the course of time, stamens or the pollen producing part of the plant were replaced by more petals. This gave rise to newer species with semi-double or double flowers that have more than 5 petals. Eventually mutations also arose that led to repeat-flowering rose species that bloom throughout the growing season.

There are 18-20 roses native to the United States. Four of these (R. acicularis, R. arkansana, R. blanda, and R.woodsii) are native to Minnesota. All 4 of these species are single-flowered, pink, and bloom in spring (Photos 1 & 2). Photo 2-1.jpg

Photo 2: R. acicularis.David Zlesak.

Given the thousands of rose cultivars in the world, you might think that many of the rose species were used in developing all of these cultivars. With few exceptions, only 8 species are ancestors to our rose cultivars and all 8 are from Asia.

As rose cultivars are developed, they are placed into classes. There are 36 classes of roses. Classes that Minnesota gardeners might be familiar with are the Hybrid Teas, the Shrub Roses, or the Hybrid Rugosas. Every rose cultivar is placed in a class with other roses who share common ancestors and/or similar floral, foliage, or plant habit traits.

Which classes and which cultivars can be grown in Minnesota? That depends on a gardener's taste in rose appearance, the choice of how much time he or she wants to devote to maintaining their roses to insure good performance and long term survivability, and a willingness or reluctance to spray pesticides. Some of the biggest factors that impact these decisions are choosing between repeat-blooming and spring-blooming cultivars, cold hardiness and pest tolerance of individual rose cultivars, and the pH of your soil.

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Photo 3: Spring flower display of 'Prairie Wren', a spring-blooming shrub rose. Kathy Zuzek.

Most gardeners today are looking for repeat-blooming roses. These are the roses that bloom repeatedly throughout the growing season. There is nothing wrong with this except that it does eliminate the potential for enjoying some of our hardiest and largest cultivars that can produce hundreds of blooms during their one season of bloom to provide a spectacular spring display (Photo 3). Entire classes of roses that bloom only in spring can be eliminated from your list if you want a repeat-flowering rose.

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Photo 4: Green canes below the snowline are alive while canes above the snowline are brown
and dead.Kathy Zuzek.

Gardeners in Minnesota also need to consider cold hardiness. Our hardiest roses that show no cane injury after a Zones 3 (northern Minnesota) or Zone 4 (southern Minnesota) winter where minimum temperatures fall to somewhere between -20 degrees and -40 degrees F belong to only a few classes of roses. Some of these hardy cultivars are repeat bloomers and some are not. Other "hardy" repeat-blooming cultivars within those same few classes will have part of their canes killed by winter injury each year after a typical Minnesota Zone 3 or 4 winter. Oftentimes these cultivars have canes alive in the lower portions of the plants that were protected by snow cover while cane portions above the snowline are winter-killed (Photo 4).

What is important in Minnesota is a plant's ability to re-grow vigorously during the following growing season after experiencing some winter injury. Because repeat-blooming roses produce flowers on the current year's wood, a repeat-blooming plant that grows vigorously in spring and summer after some winter injury can perform beautifully in spite of our harsh winters. There are also entire classes of roses that are not hardy in Minnesota. Unless a gardener is 1) willing to consider a rose as an annual plant or 2) tip and bury roses or provide some other measure of winter protection, these roses should not be grown in Minnesota.
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Photo 5:Blackspot on a rose leaflet. Dave Hansen.


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Photo 6: Swellings on a rugosa cane indicate where rose borer larvae have girdled the rose cane. Dave Hansen.


Roses are hosts to many pests. The pests that most impact rose survival in Minnesota are blackspot, the rose stem borer and a wasp that causes mossy rose gall.

Blackspot is a fungus that results in defoliation of rose plants across all classes (Photo 5). Roses without leaves cannot photosynthesize to produce and store the energy reserves that a plant lives on. Many roses that defoliate from blackspot in early or mid-summer also try to produce a new second set of leaves in late summer. This depletes the energy resources of the plant even more. Plants that are susceptible to blackspot are severely weakened by repeated rounds of defoliation and have little ability to survive our harsh winters. Plant size and vigor is diminished with each year of blackspot incidence until finally the rose is too weak to survive over winter. Along with blackspot's impact on winter survivability, few gardeners are willing to tolerate a defoliated rose in their garden. This leaves two options: planting blackspot-tolerant roses or repeated fungicidal sprays during the growing season. Some classes of roses have a higher percentage of blackspot-tolerant cultivars than other classes.

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Photo 7: Mossy rose gall on a rugosa rose. Dave Hansen.

The rose stem borer (Agrilus aurichalceus) (Photo 6) and the cynipid gall wasp (Diplolepis spinosa) that causes mossy rose gall (Photo 7) can be bothersome pests on cultivars within the Hybrid Rugosa class, especially when rugosas are mass planted. Both pests girdle a cane, resulting in cane mortality from the swelling or gall to the tip of the cane. Large infestatations of these pests that are allowed to re-infest year after year can eventually cause so much stress to rugosa roses that they die.

Roses prefer a soil pH of 6.0 to 7.0. As pH increases above these levels, iron chlorosis becomes a problem and can lead to plant stress, low vigor or mortality. Cultivars within the Hybrid Rugosa class are particularly susceptible to iron chlorosis on high pH soils (Photo 8).
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Photo 8: Iron chlorosis on a rugosa rose growing in a high pH soil.
David Zlesak.


Coming August 1 in Rose Classes and their Performance in Minnesota: Part 2: Descriptions of some common rose classes planted in Minnesota gardens and a look at some attractive, low maintenance cultivars within classes.

Peony Flower Types

Karl Foord, UMN Extension Educator

I just finished photographing the peony collection at the Minnesota Landscape Arboretum and was amazed at the variety of flower types and colors. Peony flower types fall on a continuum starting with single and progressing through semi-double, Japanese, and double. The single flower has a central cluster of carpels surrounded by a ring of stamens surrounded by a ring of petals, a basic flower structure. The following flower types all have modifications of this basic structure. The semi-double flower may have a fertile center surrounded by several layers of petals. "Japanese" peonies have modified stamens (staminoides) which may have some functional anther material and pollen, but the stamen filaments are now more like petals. In double peonies all flower parts are petals.

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According to some estimates, there are over 3,000 cultivated varieties of peony.

To identify peonies, a fairly comprehensive list is available at http://www.paeo.de/ - (Carsten Burkhardt's Web Project Paeonia). If you are interested in buying peony bulbs suppliers can be found through the plant info tab on the Minnesota Landscape Arboretum's website. (http://plantinfo.umn.edu/ and http://www.arboretum.umn.edu/ hit the plant info button top center of page). I did a search for peony and got 1297 search result(s) for Paeonia on this site.

Photo credits: Karl Foord

Gray Mold

Michelle Grabowski, UMN Extension Educator

YG botrytis 1.jpgRecent wet weather has provided perfect conditions for a common fungal disease of flowering annuals known as gray mold. Gray mold is caused by the fungus Botrytis cinerea

Photo 1: Gray mold from an infected flower moves to leaves M.Grabowski UMN Extension.

and can occur in a wide variety of annual flowers including impatiens, zinnias, geraniums and many more.

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Photo 2: Brown leaf spot from gray mold infection M.Grabowski UMN Extension.

Often called Botrytis blight, gray mold causes a dark brown to black blight of flowers, buds, leaves and stems. Flower petals are especially susceptible to infection by the gray mold fungus. Brown spots may be seen on petals or the entire flower may turn brown. As flowers age, they fall off onto healthy leaves below. The gray mold fungus then infects the leaves. Removal of these rotted petals often reveals a brown target shaped spot on the leaf which quickly grows to rot the entire leaf. With high humidity a cloud of fluffy gray spores forms on old infected leaves and petals. These spores are easily blown or splashed to new flowers to start the infection cycle all over again.

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Photo 3: Zinnia seedling from the center of a nine pack is killed by Gray mold M. Grabowski UMN Extension.

Gray mold thrives in wet crowded conditions. This time of year it can easily be found in over crowed annuals. Gardeners may have flats of annuals waiting to be planted. As these plants outgrow their small containers, humidity builds, and gray mold takes off. It is not unusual for a gardener to find the center plant of a six or nine pack completely blighted by gray mold.

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Photo 4: Gray spores of gray mold on rotted leaves and petals M.Grabowski UMN Extension.

The best management strategy to minimize gray mold in annuals is to space out plants so that leaves and petals dry out quickly after rain or irrigation. If the annuals cannot be planted in the garden due to weather conditions or other factors, take pots out of the flat and space them out to allow good air movement between plants. If plants in multipacks cannot be planted quickly, transplant them into larger pots where they will have room to grow and will not crowd one another. When planting in the garden, place plants to allow room for the mature plant. Gray mold can show up anytime wet weather occurs during the growing season.

Spent flowers and infected leaves should be pinched off and removed. Fungal spores are formed on these old rotted plant parts, so do not leave them lying in the garden. Rather collect all infected plant parts in a paper bag and dispose of them. It is ok to compost leaves and flowers infected with gray mold because Botrytis cinerea is commonly found in soil and old plant debris. With a little care most plants can recover from gray mold once warm dry conditions return.

Baptisia australis, 2010 Perennial Plant of the Year

Karen Jeannette, Research Fellow and Yard and Garden News Editor

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Photo 1: Baptisia australis 7 years after planting. Karen Jeannette.

The 2010 Perennial Plant of the Year goes to Baptisia australis, also referred to as false indigo. While many times the perennial plant of the year is in fact versatile and well-suited for Minnesota, as with any nationally nominated plant, there are years when the plant of the year does not always turn out as we hope in Minnesota, or is not hardy to any or all of our Minnesota cold hardiness zones ( 2, 3, 4).

 Baptisia australis is considered a long-lived perennial (barring any catastrophe, abuse, or major disruption to the plant or root zone) and is cold hardy in zones 3-8.  


The Perennial Plant of the Year is named annually by the Perennial Plant Association, whose board of directors include plantsmen and women who represent nurseries, universities, botanical gardens, and other horticulture entities. The Perennial Plant Association hosts a Plant of the Year Committee, who votes yearly on one of several previously nominated perennial plants, and then nominates future selections based on the following characteristics:

  • Suitable for a wide range of climatic conditions
  • Low maintenance
  • Pest and disease resistant
  • Readily available in the year of release
  • Multiple season of ornamental interest
  • Easily propagated by asexual or seed propagation

Uses and information about Baptisia australis can be found in the Perennial Plant Association's flyer, as seen here:

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As mentioned in the above flyer, Baptisia australis can be quite useful in prairie gardens, landscapes, or restoration, along with native and related species, Baptisia bracteata (cream to yellow flowers) and Baptisia alba (white flowers).  The University of Minnesota bulletin Plants in Prairie Communities: Characteristics of Prairie Plants lists all three species as being used in mesic plant prairie communities

Purchasing Baptisia australis - don't let its sparse start fool you!

Because Baptisia australis takes three years to become an established, flowering plant, note that when purchasing first year plants sold in one or two gallon pots, they will not be blooming. In fact, the two or three-stemmed potted plant may look a bit sparse next to other quicker to establish perennial plants for sale. However, just be aware that a first year false indigo plant will likely require a little imagination on your part at the time of purchase.  As long as the plant appears in good health (i.e. not wilting, foliage intact, roots whitish with no rot), these first year plants actually hold much potential. Once planted in the appropriate garden site and soil, false indigo will begin the establishment process needed to become the long-lived, drought resistant, cold hardy, and robust perennial performer it has been touted as being.

University of Minnesota Master Gardener Vegetable and Ornamental Trials for 2009

Jackie Smith, Belle Plaine, Carver/Scott Master Gardener

Over 100 Master Gardeners throughout Minnesota participated in the trials for 2009. As always, weather was a factor for many, with a long cool dry spell early in the season followed by hot and dry and then by a cool, rainy, stretch at the end. Despite the weather, our testers persevered and most successfully grew and evaluated one of the three vegetables or two ornamentals. Participants grew all the cultivars listed and evaluated yield, flavor, and ornamental value by ranking their performance from 1 to 3 (1=excellent, 3=poor).   They also recorded whether or not they would purchase the cultivar to grow again.

Lima Beans

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Photo 1: Zucchini and lima bean trials. Jackie Smith.

Lima growers sowed directly outdoors on an average date of May 30. Growers planted five or more seeds of each variety, and kept from two to three plants of each for evaluation. All varieties were marked as bush varieties. Flavor and texture were evaluated using cooked young shelled beans.


  • "Burpee Improved" averaged 2.8 light green beans per pod at 103 days from planting to harvest. The beans were quite large at .8" each, and the plants averaged 1.1 cup of shelled beans each. Ranked #1 for flavor, texture, and overall. Seventy-five percent of our testers are willing to purchase Burpee Improved in the future.
  • "Dixie Butterpea" was earliest to produce light green beans at 102 days from planting. The small, ½" beans were produced at the rate of 3.2 per pod, with an average of 1.2 cups of shelled beans per plant. Flavor and texture were ranked in 5th place, but our growers rated Dixie Butterpea last overall. Still, sixty-four percent will grow again.
  • "Eastland Bush" set light green beans at 103 days from planting. The beans averaged .6" in size-3.1 per pod- at the rate of 1.1 cup per plant. Growers rated Eastland in second place for flavor, texture, and overall. Sixty-four percent will purchase again.
  • "Henderson's Bush" also produced .6" light green beans at the rate of 2.9 per pod, 103 days from planting. Pod set was light, with a total yield of only .8 cup of shelled beans per plant. Ranked in second place (tied with Eastland) for flavor, but only 4th for texture, Henderson averaged 3rd place overall. Fifty-four percent will purchase in the future.
  • "Speckled Calico" produced beautiful large (.8") beans at the rate of 2.5 per pod, and 1.3 cup per plant. The beans were a lovely marbled combination of pink and white. Plants were slow to set fruit, averaging 109 from planting to harvest, and were large vines that required support. Flavor rated only 4th place, while texture was rated 3rd. Coming in at 4th place overall, Speckled Calico will be grown again by fifty percent of our testers.
  • "Early Thorogreen" took 104 days to harvest, producing .6" light green beans at the rate of 3 per pod and .8 cup per plant. Rated last for flavor and texture, our growers still ranked Thorogreen in 5th place overall. Only forty-six percent will grow again.

Leaf Lettuce


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Photo 2: Leaf lettuce trials. Jackie Smith.

Participants were asked to sow seeds directly outdoors as soon as the soil was workable and the danger of heavy frost past. They were asked not to thin, but to cut the plants for baby lettuce beginning at 3" in height, and to continue to harvest as often as possible. The growers sowed an average of 35 seeds of each variety on May 7.

  • "Australian Yellow" averaged 43.6 days to first harvest. Leaves were chartreuse color and our growers averaged 5.7 cuttings before the plants bolted or simply quit growing. Flavor was rated 5, and texture last, giving Australian Yellow a overall final ranking of 5. Still, seventy-three percent of the growers will try this again
  • "Black Seeded Simpson". This old standby variety is still doing well in comparison trials, ranking first for flavor and third place overall. BSS was ready to harvest at 42.8 days, and was top yielder at 6.2 cuttings. Leaves were chartreuse in color. Ninety-two percent of our testers will continue to grow this variety.
  • "Grand Rapids" also produced chartreuse leaves starting at 43.2 days from planting. Ranked 4th for flavor and 3rd for texture, this variety placed fourth overall. Harvest was relatively brief, with 4.8 cuttings, but a whopping ninety-eight percent will grow Grand Rapids again.
  • "Lolla Rossa" seed was a crop failure and a different variety was substituted by the supplier. Unfortunately, the variety name was unreadable - but the following rankings do not apply to Lolla Rossa: leaves were green with red margins with good texture but unpopular flavor. Ranked in 6th place, only 68% of our growers liked this lettuce, whatever the variety.
  • "Midnight" leaves were a uniform dark red produced at 41.8 days from planting (earliest), and continuing for 5.6 cuttings. Flavor was ranked #1, tied with BSS, and texture #2. Overall, our growers rated Midnight in first place and eighty-eight percent will purchase again.
  • "New Red Fire" plants produced green leaves with red margins at 42.8 days from sowing. Plants gave up early, however, standing up through only 4.7 cuttings. Flavor and texture were average, but New Red Fire ranked second place overall. Eighty-four percent will grow again.

Green Zucchini

Participants in this trial planted seeds directly outdoors on May 24, planting a minimum of 3 seeds of each variety. Asked to grow at least one plant of each variety, the growers averaged two or more of each. Evaluations for flavor and texture were conducted tasting raw fruit at 6" in length. All varieties produced dark green fruit that was predominantly slender and straight. Powdery mildew was rampant across the state. Vine borers and/or squash bugs were common, but no varieties were either more or less attractive to these pests.

  • "Ambassador" produced fruit at 53.6 days from sowing, at the highest rate of 14.1 fruit per plant. Ranked third for texture, Ambassador was tops in flavor and overall, with 89% of our growers willing to purchase it again for future planting.

  • "Black" took 53.3 days to harvest. One of two varieties with large leaves that seemed somewhat less prone to mildew. Texture was ranked second, but Black's flavor was the least favorite. Production was average at 12.8 fruit per plant. Our growers ranked this third overall and seventy-one percent are willing to buy again.
  • "Cashflow" was the earliest to harvest at 52.2 days from planting. Texture wasn't a favorite, but testers rated it second for flavor. Plants averaged 13.6 fruits. Ranked fifth overall, only fifty-nine percent will purchase Cashflow in the future.

  • "Dark Green" also produced large mildew-resistant leaves with fruit ready to harvest 54.3 days from planting. Plants averaged 12.8 fruits each, with top rated texture. Ranked last overall, still seventy-eight percent will grow Dark Green again.
  • "Emporer" ranked fourth for flavor, texture and overall. The plants were slowest to produce fruit, at 55.6 days from planting, and averaged only 9.6 fruits each. Seventy-eight percent of our growers were still willing to try this variety again.

  • "Spineless" texture placed last in our grower's opinions, but flavor was average. Plants produced fruit sooner than others at 49.3 days from plants, with an average of 13.8 fruit per plant. Ranked in second place overall, Spineless will be purchased again by 83% of our testers.


Dianthus

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Photo 3: Dianthus varieties. Jackie Smith.

Growers were asked to start seed indoors as soon as received (average March 15) and to select at least three plants of each variety to transplant outdoors for evaluation in this trial. Transplanting was to take place when weather was warm and settled, with the actual average transplanting date of May 26, 2009. Varieties grown were all relatively low plants and were not meant to be color mixes. In addition, none were notably fragrant. In most cases, bloom was curtailed only by frost at season's end.



  • "Corona Cherry" plants averaged 7.7" tall by 8.0" side, with 2.0" single blooms in varying shades of raspberry pink. Ranked in third place for amount of bloom, and fourth place overall, Corona Cherry will be purchased again by 77% of our trial participants.
  • "Crimson Carpet" produced attractive blue leaves when out of bloom on plants that averaged 8.5" tall by 7.4" wide. Ranked in fourth place for amount of bloom, plants produced single red blooms that averaged 1.4" in diameter. Placing last overall, only 57% will purchase Crimson Carpet again.
  • "Ideal Red" single blooms were 1.4" in diameter in a pleasing shade of warm rosy red on plants that averages 8.7 inches by 8.5 inches. Ranked second for amount of bloom, this variety also placed second overall. A full 80% will grow Ideal Red in the future.
  • "Parfait Raspberry" large single blooms averaged 1.8" in raspberry shading to cream edges. Plants averaged 8.0" by 8.3", with blue leaves. Flower production was the lowest in the trial, but because of the large bloom size, there was plenty of flower-power. Ranked number one overall, Parfait Raspberry will be grown again by 73% of our testers.
  • "Snowfire" is our third variety with blue leaves. Plants were a bit larger than the others at 10.2" tall by 8.9" wide. The 1.6" blooms were a little more sparse than most (5th place) and were single, with smallish fire engine red centers on white petals. Ranked fifth overall, sixty-seven percent will purchase Snowfire again.
  • "Telstar Crimson" produced small (1.3") single red flowers abundantly (ranked #1 for production). Plants grew to 9.3" tall by 8.9" wide. Growers rated this in third place overall and a very strong 82% will purchase Telstar Crimson in the future.

Rudbeckia


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Photo 4: Rudbeckia "Prairie Sun' and 'Cherry Brandy'. Jackie Smith.

Growers were asked to start seeds indoors (average starting date was March 23), and to transplant outdoors in full sun when the weather was warm and settled (average May 28). They started an average of 8 seeds of each variety, and averaged one to three plants of each by trial end.

  • "Cappuccino" plants averaged 21" tall by 17" wide. Petals of the single, 4.6" blooms were gold with rust toward the brown centers. Ranked the most floriferous of the varieties tested, Cappuccino tied for number one overall, along with Cherry Brandy. Eighty-nine percent of our trial participants will purchase again.
  • "Cherry Brandy" is an unusual color breakthrough for Rudbeckia with burgundy petals backed with pink and brown centers. The single blooms averaged 3.1" in diameter and were ranked second in flower production. Plants grew to 26" tall by 16" wide. Tied for number one overall with Cappuccino, Cherry Brandy exceeded it in popularity with a full 100% of the growers interested in trying it again.
  • "Chocolate Orange" seed caused problems for several growers, with a dismal 28% germination rate. Those who were successful were rewarded with 3.5" single blooms with petals showing orange tips and dark red toward the dark centers. Bloom amount ranked third on plants that grew to 23" tall by 16" wide. Rated in third place overall, 94% of our growers will continue to grow Chocolate Orange.
  • "Indian Summer" produced very large, 4.5", single gold blossoms with dark centers on plants that grew to 29" tall by 18" wide. Ranked fifth for flower production and fifth overall, Indian Summer remains popular enough to encourage 94% to continue to grow it in the future.
  • "Maya" was at a disadvantage grown against the others since it was the only double flower on much smaller plants, which grew to only 16" tall by 12" wide. The gold blooms were 2.9" in diameter, but flower production was only average or below. Ranked in 6th place overall, only 33% will grow Maya again.
  • "Prairie Sun" differed from the others by being the only variety with light green centers. The blooms averaged 4.2" diameter, and the gold petals had lighter yellow tips. Coupled with the green centers, the overall effect of the blooms was a paler yellow. Plants grew to 28" tall by 17" wide, but flower production was rated least of all tested varieties. Growers ranked Prairie Sun fourth overall, but enjoyed it enough to encourage 90% of them to purchase it in the future.

Asian Vegetables

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Photo 5: Red noodle bean was part of the Asian vegetable variety trials. Jackie Smith.

The Fingerprint of a Virus

Michelle Grabowski, University of Minnesota Extension Educator

Cyclamen are popular plants to brighten the home during the winter months. Flowers come in multiple shades of pink, red, lavender and white. When the blooms are spent cyclamen have interesting white patterns on their leaves, varying from an almost complete white horseshoe to regularly spaced white blotches depending on the cultivar. These leaf patterns are normal for cyclamen and make them an interesting foliage plant.

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Photo 1: INSV symptoms on cyclamen. Photo by K. Snover-Clift, NPDN .

Patterns that indicate a problem

Gardeners should beware, however, of leaf patterns that occur on some leaves but not others. The natural white color patterns on cyclamen leaves should be fairly consistent on all of the plant's leaves. If you are noticing unusual color patterns on some leaves but not others, this may be a symptom of a common viral infection.

Cyclamen are one of many hosts to the plant virus Impatiens Necrotic Spot Virus (INSV). This virus was first discovered on impatiens plants showing dark colored ring spots on its leaves. Since then it has been discovered that INSV can infect over 300 species of plants. Many flowering house plants, annuals, vegetables and even weeds can be infected with INSV.

The symptoms of INSV vary from plant to plant and even between cultivars. Some plants have random brown dead spots on leaves or streaks on stems. Others are stunted, wilt and die. Many have ring spots on leaves. Cyclamen infected with INSV have random brown spots, often with one or more brown rings around them. In many cases, multiple yellow to brown rings form on infected leaves, looking almost like a fingerprint. These types of ring spots are characteristic of viral infection.

How did my plant get infected?

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Photo 2: INSV symptoms on cyclamen. Photo by K. Snover-Clift, NPDN .

INSV is transferred from plant to plant by western flower thrips (Frankliniella occidentalis), a common insect pest found in greenhouses. Thrips larvae that feed on an INSV infected plant pick up the virus. The virus survives within the thrips and the adult thrips are able to transmit the virus to any plant that they feed on for 5-10 minutes. Once infected with INSV, thrips carry the virus with them for the rest of their lives. Infected house plants could have been infected at the time of purchase or thrips carrying the INSV virus could have been brought into the house on the cyclamen or other plant.

What can I do about INSV?
Unfortunately plants infected with INSV can never be cured. They will carry the virus with them for the rest of their lives and can pass it to other plants if western flower thrips are present. Therefore it is best to destroy infected plants to prevent the spread of the disease. Plants infected with INSV can be thrown into the compost pile because the virus will not survive without a live host plant. If thrips are a problem on this or other houseplants, steps should be taken to control them. Many cultural and chemical control strategies are available to manage thrips and can be learned by reading the UMN extension publication 'House Plant Insect Control'. Remember, only thrips that have fed on an INSV infected plants will be able to transmit the virus, so the presence of thrips alone does not mean that plants are infected with INSV.

The best management strategy is to avoid bringing home plants that are infected with INSV or western flower thrips. Before purchasing a cyclamen, inspect both the upper and lower surface of the leaves for unusual yellow to brown spots, especially ring spots. Thrips may be difficult to see without a hand lens since they are only 1/16th of an inch long and very thin. Tapping the leaves of a plant over a white piece of paper can knock off some insects that you will then be able to see moving across the sheet.

Unfortunately plants recently infected with INSV may not show symptoms for a week up to a month. It is therefore possible to purchase a healthy looking infected plant. To avoid future problems, keep the new plant separate from other plants in the house for about 2-3 weeks. This will allow time for symptoms of the virus or thrips feeding to develop without allowing the problem to spread to other house plants.

For more information about general cyclamen care, read the UMN extension publication 'Cyclamen care'.


University of Minnesota 2009 Annual Flower Trials

Karen Jeannette, Horticulture Research Fellow & Yard and Garden News Editor

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Photo 1:  Ornamental Pepper 'Black Pearl' was a top 10 performer in St. Paul, but grew less profusely in Morris and Grand Rapids, MN locations. Karen Jeannette.

Each year researchers and scientists from the University of Minnesota, Department of Horticultural Science grow, display, and trial hundreds of annual flowers at several Minnesota locations, then report how well these annual varieties perform for that season.

For Minnesota gardeners and industry professionals, the yearly University of Minnesota Annual Flower Trial sheds some light on how certain annual flower varieties will perform under different Minnesota conditions, and which ones are top selections for Minnesota overall.  St. Paul, Morris, and Grand Rapids, Minnesota were home to the 2009 display and trial gardens, as in past years.  These locations differ in their hardiness zones, heat zones, and growing days (see the section Top 10 Performing Annuals for 2009 by Site for details).  2009 Annual Flower Trial winners had to perform well despite cooler than average conditions through much of the summer growing season (Grand Rapids reported growing degree days for June through August were 16% below the 30-year average), followed by warmer than average September conditions. Thus, making for a somewhat challenging year for many annuals, especially those that perform best under warmer summer conditions.

Criteria for evaluating the 2009 annual flower trial cultivars include whether they were diseased (no/yes), average flower size, plant uniformity (1=poor, 5=excellent), and plant and flower ratings (1=poor, 5=excellent).  

 With differences in growing conditions across the state, having a top ten list for each annual flower trial location can prove helpful for gardeners trying to select varieties that perform well in similar growing conditions. Here are the 2009 top performing annuals by site:

Top 10 Performing Annuals for 2009 by Site

St. Paul, MN (USDA Winter Hardiness Z4; Heat Z5; 169 growing days)
Neil Anderson, Floriculture Breeding, Associate Professor, Department of Horticulture Science
http://horticulture.cfans.umn.edu/

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Photo 2: Les Bolstad Golf Course, St. Paul 2009. Annual Flower Trial report.

1. Colocasia 'Heart of the Jungle'
2. Millet 'Jade Princess'
3. Petunia 'Debonair Lime Green'
4. Petunia 'Pretty Much Picasso'
5. Petunia 'Sophistica Antique Shades'
6. Ornamental Pepper 'Black Pearl'*
7. Osteospermum 'Asti White'*
8. Gaillardia 'Mesa Yellow'*
9. Dianthus 'Bouquet Rose'
10. Carex 'Graceful Grasses Toffee Twist'

*=All American Selections cultivar

Morris, MN (USDA Winter Hardiness Z3/4; Heat Z4; 144 growing days)
Steve Poppe, Horticulture Scientist,  West Central Research and Outreach Center
http://wcroc.cfans.umn.edu/Horticulture.html

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Photo 3: Coleus 'Trusty Rusty'. 2009 Annual Flower Trial report

1. Petunia 'Ray Purple Vein'
2. Lobelia 'Techno Heat Upright Blue'
3. Petunia 'Suncatcher Red'
4. Geranium 'Calliope Scarlet Fire'
5. Petunia 'Supertunia Vista Bubblegum'
6. Diascia 'Flirtation Orange'
7. Coleus 'Trusty Rusty'
8. Begonia 'Braveheart Rose Bicolor'
9. Viola 'Skippy XL Red-Gold'
10. Verbena 'Superbena Coral Red Improved'



Grand Rapids (USDA Winter Hardiness Z3; Heat Z3; 109 growing days)
Shengrui Yao, Research Fellow, Grand Rapids, MN
http://ncroc.cfans.umn.edu/Horticulture.html

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Photo 4: Petunia 'Supertunia Vista Bubblegum'. 2009 Annual Flower Trial report.

1. Petunia 'Pretty Much Picasso'
2. Petunia 'Supertunia Vista Bubblegum'
3. Ipomoea 'Illusion Midnight Lace'
4. Delphinium 'Diamonds Blue'
5. Lobularia 'Snow Princess'
6. Cyperus 'Graceful Grasses King Tut'
7. Verbena 'Lanai Royal Purple'
8. Colocasia 'Heart of the Jungle'
9. Cleome 'Senorita Rosalita'
10. Rudbeckia 'Denver Daisy'


All American Selections

All three Minnesota flower trial locations involved in the 2009 Annual Flower Trial are also All America Selections Display Gardens, (AAS) since 1990, and grow the AAS winners from the past five years. The AAS Award recognizes a flower or vegetable variety proven to be superior to all others on the market.  In 2009,  St. Paul was the only Minnesota location with All American Selection cultivars in its Top 10 Performing Annuals list. There were, however, four AAS cultivars highlighted as performing good or excellent at two or three Minnesota trial locations under 2009 conditions. These highlighted AAS cultivars include:

  • Celosia 'Fresh Look Gold'
  • Nicotiana 'Perfume Deep Purple'
  • Petunia 'Opera Supreme Pink Morn'
  • Salvia 'Evolution


The Full 2009 Annual Flower Trial Report

So which other annual flowers performed best across Minnesota locations?  Evaluation data for hundreds of annual flower cultivars can be found in the full 2009 Annual Flower Trial report.  Highlighted in grey are cultivars rated as good to excellent under 2009 conditions for at least two or three locations.  See page one under Flower Cultivar Evaluation Data to gain further insight as to how these highlighted cultivars are evaluated for the 2009 Annual Flower Trials. The report can be read here:

FlowerTrial 2009-1.pdf


The 2009 University of Minnesota Annual Flower Trials certainly give us an idea of which annual flowers performed the best under 2009 growing conditions.  Now it's up to Minnesota gardeners and nurseries to continue evaluating these new flower cultivars in 2010 under a new year's growing conditions, in new sites, and with different caretakers. May the best varieties win!

An Un-Ordinary Growing Season for All-American Selections at the MN Landscape Arboretum

Redistributed with permission from Arboretum News, Dec./Jan. issue
Ted Pew, Landscape Gardener, University of Minnesota Landscape Arboretum


The All-America Selections gardens this year at the Minnesota Landscape Arboretum were a mix of strange and stranger. For starters was the weather. Snowfall last year was low with minimal moisture content. The growing season--the end of May to the end of July--was cooler than normal. August was a bucket load of moisture but summer came in September with 80 degree temperatures and dry conditions. The 2010 AAS winners featured flowers only. The strange factor about the AAS was the expected colors on certain annuals. We had three outstanding cultivars for the 2010 sneak peek despite four plant diseases in the AAS bed and a crop failure.

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Photo : Twinney Peach Snapdragon (Antirrhinum majus 'Twinney Peach') All-Americas Selections.

Twinney Peach Snapdragon, aptly named for its color, had a double flower form with soft shades of peach, yellow and light orange color tones. This cultivar was quite floriferous--blooming early and up to frost--with a manageable sized 12" height and flowers up to 1.25". We had a fusarium or Pythium disease problem but once that is solved this cultivar will be around for years to come. The plants seem to be weather resistant and relatively maintenance free, for small space garden to any type of container.


Like the Snapdragon, Mesa Yellow Gaillardia was unique with its controlled plant habit and very floriferous flowers that continued to bloom through the summer. Gaillardia attracts butterflies; Mesa Yellow had an improved mounded plant habit of 20-22" in a full sun location.

Zahara Starlight Rose got rave revues on its stunning flowers from volunteers, staff and visitors. A new bicolor for this sun-loving annual, other good traits not found in many Zinnia cultivars included as leaf spot and mildew resistance. What slowed it down was the disease Sclerotinia, which affects other annuals as well. The flower form is a composite single rose and white bicolor growing up to10-12" blooming early and continuing to frost due to its disease resistance. Zahara Starlight Rose is heat and drought resistant and very floriferous.

I can't tell you much about Viola"Enduric Sky Blue Martien" except that we had a crop failure. These three plants are outstanding in their own way and will be grown again next year.

Edible Landscape Wrap-Up

Emily Tepe, University of Minnesota Research Fellow, Department of Horticultural Science

After many weeks of harvesting mountains of chard, tomatoes, zucchini, peppers, cucumbers, raspberries and a multitude of other vegetables, fruits and herbs, the University of Minnesota Edible Landscape has been put to bed. Well...almost. The few lone stands of silvery blue kale seem to mock the cold, their leathery leaves sweetening with each frosty night. And many of the herbs are even holding onto their green. Other than those, the Edible Landscape is now resting after a long and productive season. snow on kale_tepe.JPG

Photo 1 (left and above): Snow on dinosaur kale in the University of Minnesota Edible Landscape on October 12, 2009. Emily Tepe.

If you haven't had a chance to see the gardens on the St. Paul campus this year, and if you haven't been following the Edible Landscape blog, here's a rundown of some of the details of the project. The Edible Landscape filled four beds outside the Plant Growth Facilities on Gortner Ave. The 1500 square foot garden was comprised of 75 varieties of fruits, vegetables, herbs and flowers. The garden was designed to emphasize the ornamental qualities of edible plants, and demonstrate how these plants might be incorporated into the home landscape in creative, attractive ways. Most of the ornamentals, herbs and warm season crops were started from seed in the greenhouse during the winter months. Others, such as chard, kale, summer and winter squash, melon, lettuces and radishes were direct seeded throughout the season. By mid-October, almost 500 pounds of produce had been harvested from the Edible Landscape and shared with students, faculty and staff in the Department of Horticultural Science.

After cleaning all the annuals out of the garden (which were then composted), winter rye seed was raked into the beds for a winter cover crop. It may sound strange to think of cover crops in a home gardening demonstration. After all, we normally think of cover crops being used on acres of land, not in the backyard. But cover crops in the home garden can offer great benefits such as weed suppression, erosion control, increased microbial activity and moisture retention, just to name a few. You can read about Green Manure Cover Crops for Minnesota on the U of MN Extension Website.

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Photo 2 (right and above): The largest bed in the University of Minnesota Edible Landscape in mid-July. Emily Tepe.

If the idea of edible landscaping sounds intriguing, or if you would simply like to learn more about this project, visit the Edible Landscape blog. The entire season was documented on the blog, which is filled with photos, design ideas, plant lists, growing information and more. Now that the harvests have finished, and the season is being evaluated, there will be more discussions on the blog about plant combinations that worked well, successful varieties, and lessons learned. Read, learn, share and join the discussion.

What's Up With That?!

AARS entry 09R408This is sure a unique rose with its purple-red petal bases!! It is the new All-America Rose Selection (AARS) floribunda entry coded 09R408. Why haven't we seen this dramatic petal trait before in the roses at the local garden center? The answer is that this trait has been very difficult to bring it into modern rose cultivars and is coming from a source other than rose. One of rose's closest relatives, Hulthemia persica, is the source. Over the past 30+ years dedicated breeders have painstakingly made crosses between this wild rose relative and rose and then have made repeated backcrosses to rose.  The backcrosses to rose have been to gain more rose characteristics while still trying to retain the attractive red petal bases. Hulthemia persica is native to the region once part of the old Persian empire. It is typically found growing in very dry areas and has been difficult to cultivate in typical garden settings due to relatively high humidity and soil moisture compared to where it is native. It is different than rose (Rosa) in that it 1). does not have the two pointed paired stipules at the base of the leaf where the leaf attaches to the stem, 2). has only a simple leaf with one leaf blade rather than a compound leaf with multiple leaflets, and 3). it has a deep red blotch at the petal base. Hulthemia persica typically has rich yellow petals with deep red blotches.

New Lily Classes Grow in Availability and Popularity

David C. Zlesak, University of Minnesota Extension Educator

Martagon, Asiatic, Oriental, trumpet, and tiger lilies (blooming approximately in this order from late spring through summer) are groups of amazing lilies that have beautifully graced our Minnesota gardens for decades. The martagon lilies have beautiful whorled foliage, flower early with wonderful clusters of typically downward facing flowers with recurved petals, and are even relatively shade tolerant. The Asiatic lilies are probably the easiest for us to grow here in Minnesota. In amenable sites they typically multiply well and provide a glorious show of blooms in probably the widest color range possible of all the different commercial lily classes. The Oriental and trumpet lilies have large, intoxicatingly fragrant flowers. The fragrance is especially powerful in the evening and throughout the night. I love coming home at night and being taken back by the rich, wafting fragrance of my Lilium regale lilies (a white trumpet lily) and ‘Casa Blanca’ Oriental lilies as I walk to the front door. Tiger lilies have magnificently speckled orange or yellow blooms typically with recurved petals similar to the martagon lilies.art3-1_600.jpg

art3-2_600.jpg We can routinely find cultivars of these traditional lily groups in our favorite catalogs and garden centers. However, in recent years there has been amazing advancements in very wide crosses between lily classes that previously were not able to produce successful offspring. Crosses between different classes have led to the development of new lily classes with many of the positive features of their parents. Special pollination techniques and techniques using tissue culture to “rescue” embryos have made it possible to recover hybrids from these wide crosses. These wide crosses are often called intersectional crosses because they are crosses made between different sections of the genus.

Botanically under the level of genus (Lilium is the genus of true lilies) there is the taxonomic level of section. Lily species that are within the same section are more similar genetically than lily species in different sections and tend to cross more easily among themselves (typically without the aid of tissue culture). For instance, crosses of multiple lily species in the section Sinomartagon led to the modern Asiatic lily cultivars we enjoy. Without tissue culture, sometimes intersectional hybrid embryos form, but the nutritive tissue (endosperm) around the embryo fails within a couple to few weeks after pollination and then it dies. If the embryo can be removed from the mother plant before it dies and placed in tissue culture where it can receive the nutrition it needs and continue growing. There are several modifications that can be made to the process in order to find ways that will work to recover different wide crosses.

These are some of the most popular intersectional lily classes on the market.

LA Hybrids

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LA refers to Longiflorum and Asiatic. These lilies are crosses between Easter lily (Lilium longiflorum) and Asiatic hybrids. They first came on the market in the early 1990’s. They look a lot like Asiatic lilies (flowers tend to be flat like Asiatics), but tend to have larger flowers with thicker petals than the Easter lily parent. Early LA hybrids tended to have colors within the pastel shades. Breeders have been able to backcross early LA hybrids to Asiatic lilies to intensify color and strengthen hardiness and other traits. Interestingly, breeders have not reported successful backcross hybrids to Easter lily parents. Modern LA hybrids tend to be as durable in Minnesota as Asiatic lilies. They are used widely in the cut flower industry and tend to be relatively easy to force in pots like Easter lilies.

Orienpet Hybrids

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Orienpets are crosses between Oriental and trumpet lilies. They tend to have huge, wonderfully fragrant flowers in a very wide array of colors and color combinations. The flowers generally tend to be more open faced like the Oriental parent. In Minnesota Orienpets tend to be more adaptable and durable than Oriental lilies. Plants typically are quite large. Many common Orienpet hybrids routinely grow to about 6’ tall and benefit from staking. The North American Lily Society has a yearly popularity poll. Those that win over multiple years are eligible to eventually be elevated into the lily Hall of Fame. Two very popular Hall of Fame lilies are of the Orienpet class and are ‘Silk Road’ and ‘Scheherazade’. ‘Silk Road’ is a lovely red / white bicolor and ‘Scheherazade’ is beautiful red / yellow bicolor.

LO Hybrids

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LO hybrids are crosses of Easter lily and Oriental lilies. They have just come into the marketplace the past few years. The most common cultivar gardeners are likely to find is ‘Triumphator’. In many ways it looks like an Easter lily with its beautiful, elongated trumpet, but the throat of the bloom is a gorgeous, rich red. It will be exciting to see more LO cultivars come on the market in the near future. Early reports are favorable for ‘Triumphator’ being able to overwinter in Minnesota. More time is needed to be confident how well cutivars of this new class will routinely perform in Minnesota.

Progress is being made on additional intersectional classes. For instance, there are beautiful hybrids in existence between martagon and Asiatic lilies. Hopefully soon they will become widely available. Recent intersectional lily hybrids offer even more great lily options for the Minnesota gardener.

The North American Lily Society (NALS) is a great resource to learn more about lilies. There are also local chapters. In addition, NALS has a nice seed exchange they host each year where members can obtain seeds of amazing lily species and also seeds of crosses and open pollination of lilies in almost every major class.

Clematis Growth Types and Pruning

Karl Foord, University of Minnesota Extension Educator

art1-1_600.jpgClematis is a genus that is best known for its vining members that produce large, colorful, showy flowers. This is at best only half of the truth. In fact many of the cultivars do produce spectacular flowers with colors from almost all 360 degrees in the gardener’s color wheel. In addition there are varieties with smaller nodding flowers that add a certain delicacy to the garden as well as some herbaceous types that are more shrub-like and die back to the ground each year. Clematis require a certain effort to make them thrive but it is well worth the effort.

The dizzying array of cultivars can be intimidating, but this can be simplified by categorizing plant types by when they set their flower buds. This will then determine when they will flower and how they should be pruned. As such, the categories are often labeled as pruning groups.

Group A*

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In this group flower buds are initiated on this year’s vine in July and then produce flowers in the late spring of the following year. If you prune off old wood you also prune off flower buds. So if you have a clematis vine and do not know the variety, observe its time of flowering. Those that flower before early summer are likely in this group. Pruning of this type should only serve to maintain the framework. Do so only after flowering and before July. Common species in this group include Clematis alpina and C. macropetala and are characterized by smaller 1” to 3” nodding flowers. Clematis alpina ‘Pamela Jackman’ and C. macropetala ‘Markhams Pink’ are cultivars of these groups that flower in May and thereafter produce attractive seed heads. Simple Rule: “If a clematis flowers before early summer, do not prune it.”(1)

Groups B1 & B2

In this group flower buds are produced on both old and new wood. The group can be divided into varieties that have two flower flushes (B1) and continuous flowering (B2). (2)art1-3_600.jpg

The B1 group flowers in early summer (May-June) from buds initiated the previous summer and in late summer (September) from buds initiated on the current year’s growth. The late summer flush is typically smaller than the early summer flush. Cultivars showing this pattern of flowering are ‘Haku Ookan’, ‘Miss Bateman’, ‘Lincoln Star’, and ‘Nelly Moser’. Interestingly, the cultivars ‘Belle of Woking’ and ‘Daniel Deronda’ produce double and semi-double flowers, respectively from old wood and single flowers from new wood.

art1-4_600.jpgRemove dead and weak stems in late spring prune after first flush of growth. Simple Rule: “Do not indulge in large-scale pruning of old wood made during the previous season(s) or there will be a loss of early flowers.”(2)

The B2 group shows a continuous flowering pattern lasting from June to September. Flower buds were initiated the previous year (old wood) and in the current year (new wood) in the same manner as the B1 group. However, this group does not demonstrate a rest period between two growth flushes. Cultivars showing this flowering pattern are ‘The President’ and ‘General Sikorski’ (photo).

Group C

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Group C plants only initiate flower buds on the current year’s growth. This pushes the flowering time to later in the season- July through September. The goal in pruning this group is to eliminate all of last year’s growth and leave the lowest pair of live buds on the plant to begin the current season’s growth. This encourages plants to produce strong new shoots from the base and flower well. Typical of this flowering pattern are the Tangutica, Texensis and Viticella groups and cultivars ‘Madame Julia Correvon’ (photos). Clematis integrifolia is a group C plant with a bush habit that only reaches two to three feet in height (photo).

art1-6_600.jpgI recommend that you consider clematis for your garden or if you have some already, consider adding more as part of you next gardening adventure. Always provide a climbing surface for the climbing clematis forms and secure stems to the surface. If this is not done winds can buffet and break the vines leading to a very unsatisfactory outcome.

*The A, B1 & B2, and C groups are often named 1, 2, and 3, respectively by some authors.




References



  1. Mary Toomey & Everett Leeds, An Illustrated Encyclopedia of Clematis, Timber Press, Portland, Oregon, 2001.

  2. Fred Wein et. al., The Concise Guide to Clematis in North America, Clearview Horticultural Products Inc., Home of ClematisTM

University of Minnesota Edible Landscape - A Demonstration Garden Incorporating Fruit and Vegetables into the Home Landscape

David C. Zlesak, University of Minnesota Extension Educator

art2-1_600.jpgEarlier this year in the May 15th Yard & Garden News, we featured Emily Tepe’s informative article on Woolch™ in the Mid-May Yard and Garden News as a new mulch for both commercial and home garden use. Emily planted a fantastic demonstration garden where Woolch™ would be featured. She invited us to come and see this garden on the St. Paul campus in front of the Plant Growth Facilities near the ‘Seed of Knowledge’ sculpture (across the street from the Display and Trial Garden). This garden is looking great and has much more to see in addition to strawberries and other plants growing with Woolch™. This garden integrates fruits, vegetables, and flowers into a very ornamental and functional landscape. Please come and visit the garden this summer. If you are not able to make it out or would like to just learn more about this great garden, Emily has created a blog about the garden at http://umediblelandscape.blogspot.com.

Rose Acacia - A Shrub with Showy Pink Flowers

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David C. Zlesak, University of Minnesota Extension Educator

Rose acacia (Robinia hispida) is in full flower across Minnesota. It is a plant many people are unfamiliar with and are asking what it is. The abundant pendulous clusters of rosey pink, pea-shaped flowers makes it especially showy this time of year. Although it is native to the Southeastern United States and is often listed as hardy to zones 5 or 6, forms of it are perfectly adapted across Minnesota and do not suffer dieback. Although not readily for sale in the garden centers, once planted (typically shared among friends) it tends to persist. The amount of it therefore continues to increase across Minnesota landscapes.

Thousands Visit Morris Bedding Plant Trials

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Steve Poppe, University of Minnesota Scientist, West Central Research and Outreach Center

In the past, no other segment of the floriculture production industry has enjoyed public interest and use of its product more than bedding plants (annual flowering plants). Bedding plants are an indispensable item for landscape use, presenting an array of flowers and foliage that add color and texture to the landscapes of homes, apartment complexes, shopping malls, public buildings, city streets and parks.

The University of Minnesota supports this growing industry through annual flower trials conducted at Morris, St. Paul and Grand Rapids. In 2008, we evaluated annual flowers from eighteen major plant companies. Our gardens are open to the public and industry for selfguided tours throughout the growing season, providing a unique opportunity to compare performance of bedding plant cultivars under regional conditions. The public's response to the 2008display gardens at all locations was very positive. Several thousand people visited these sites during the summer. Numerous educational programs and garden tours were provided at all sites, highlighting the outstanding annuals in our trials.

A Summer Minnesota 'Snowstorm'!!!

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David C. Zlesak, University of Minnesota Extension Educator

‘Snowstorm’ is the first wand flower (Gaura lindheimeri) release from the Flower Breeding and Genetics program led by Dr. Neil Anderson! Wand flower is a prized garden subject because it: blooms continually throughout the summer, is a great filler plant that mixes well with other plants in garden beds and containers, and it moves in the wind adding extra ornamental appeal. Gaura lindheimeri has grown in popularity over the past decade and is among the top 25 selling perennials in the US market today. Although this Gulf Coast native (Texas and Louisiana) is reliably hardy only to zone 6, it serves as a great annual in Minnesota.

Rose Rust Takes Off this Spring

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Michelle Grabowski, University of Minnesota Extension Educator

Cool temperatures this spring seem to be encouraging rust fungi on roses. Several different species of Phragmidium (the rust fungus) can infect both wild and cultivated roses. Gardeners should keep an eye out for two different forms of this fungus.

Bright powdery orange spores, known as uredinia, are likely to catch a gardener’s eye. These spores form in raised pustules on the underside of infected leaves, stems, or petioles (central portion of the leaf that the individual leaflets are connected to). Yellow to brown leaf spots may be noticeable from the top surface of the leaf but may not form on all rose cultivars. Infected petioles and young green stems may actually become twisted and distorted around the site of the infection. Rust fungi can infect all plant parts except the roots and gardeners may notice bright orange pustules in unusual places!

Oriental Poppies Take Center Stage!

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David C. Zlesak, University of Minnesota Extension Educator

Glowing, vibrant blooms bring oriental poppies (Papaver orientale) to center stage this time of year. The large (4-6”) flowers have crêpe paper-like petals and are held high above the foliage on strong, yet wiry stems. In a gentle breeze they almost appear to dance. The finely cut foliage makes a great backdrop to the flowers and the abundant, almost downy hairs that cover the foliage and stems set Oriental poppies apart from most other commonly grown poppies.

Native to central Asia where summers are warm and dry, these magnificent poppies have developed a unique adaptation method. When moisture is relatively abundant in spring, leaves emerge and plants quickly come into flower. As temperatures rise and moisture becomes less abundant, the foliage begins to die back and plants go dormant. As temperatures begin to cool in the fall and rains return, new foliage again emerges.

Tips for creating successful window box planters

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David C. Zlesak, University of Minnesota Extension Educator

The popularity of creatively combining different plant materials in window boxes has soared in recent years. Combining plants of various color, texture, and plant habit to design what in essence become miniature landscapes provides gardening enjoyment from both outdoor and indoor vantage points.  Designing and having window boxes can become a very fun, creative, and rewarding endeavor. The diversity of plant materials to choose from and effects that can be generated seem almost limitless.  Many people choose to try different combinations and overall themes each year.  This makes it exciting for neighbors and passersby as they anticipate what will be next.

Tuesday Evening Classes Held Throughout the Summer at the Master Gardener Education & Research Display Garden in Rosemount, Minnesota

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If you are looking to get fresh ideas for your garden, to see the latest in University flower, fruit, and vegetable varieties and accompanying research for yourself, or just to experience a beautiful, accessible garden, you will want to visit the 6-acre Master Gardener Education & Research Display Garden! There are over 25 different display and trial gardens to see.  They are well-labeled and a fantastic resource for Minnesota gardeners.

The garden is free to the public and open daily (sunrise to sunset) with plenty of free parking available. It is located on the South side of Highway 46 in Rosemount, Minnesota, just two miles East of Highway 3. It is within and part of the 5,000 acre UMore Park (University of Minnesota Outreach, Research, and Education Park). The garden started in 2001 with the purpose of being a display garden serving the public through education and research.  It is located in the Southeast metro and has a much different flavor and a unique purpose compared to the Minnesota Landscape Arboretum located in the West metro. 

Garden Calendar for June

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Contributors: Kathy Zuzek and David C. Zlesak, University of Minnesota Extension Educators

June is an amazing month in Minnesota- perhaps the most enjoyable one of all with generally nice weather and the fast rate of growth of plants in our gardens.  It is definitely a month when there is a lot to enjoy in our gardens.  Early season vegetables are ready for harvest and our ornamental plants are growing strong.  In the midst of everything going on, please don’t forget to take time to relax and “smell the roses”.

Danger of frost and very cool night time temperatures are finally over for most parts of Minnesota.  This means we can put out our warm season vegetables and flowers that are sensitive to chilling injury.  This includes: tomatoes, peppers, cucumbers, squash, melons, cannas, coleus, and impatiens.  Perhaps we have put some of these crops out earlier and protected them from frost.  It is amazing how just cool night time temperatures in the high 30’s and low 40’s F can stunt growth of warm season crops. Warm season plants put out in our gardens now can outgrow those that may be suffering from chilling injury from our excitement to get them in early even if we protected them from frost. 

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