At the nursery we have almost finished a job that has been a standing order since last fall. This is our pot-in-pot system. It is basically a field of plastic pots dug into the ground. there are 168 15 gallon pots, and room for two more rows (28 per row) of larger 30 gallon pots. The pot in pot field sits in the southeast corner of the nursery, going along the fence.

The system is used to help trees survive the winter. All of the trees in our nursery need winter to maintain their life cycles, but they also need to maintain certain temperatures. If their roots were in the ground, they would be much warmer than when they are potted above ground, without insulation from the soil. The pot-in-pot system allows us to have trees in the ground, but also keep them mobile for fall and spring plantings.

After we finish the pot-in-pots, the new ones will start to look like the olds ones, the next steps being turf, wraps, and irrigation. We cover up the patches in between with grass, spaced so that a mower can ride between the rows, and lay an irrigation line with drippers for every tree. Out of the trees that were in there last winter, only a few died, and the system is working very well. We hope that it will still be there in 10 years.

A special thanks to Matt, Jonathan, Charlie, Chad, and the Nicks.

This week's tree is the Chinese catalpa (Catalpa ovata). They are easily recognized by their long thin pods and their heart shaped leaves. They differ from the native variety by having longer pods, and 

purple tinted leaves. Just recently we planted a few flats of them in one of our fields, replacing the winter kill from last year.

Chinese catalpa is obviously not native plants, but they work well in Minnesota, and have been successful in urban environments.  A good example is still flourishing next to the stone arch bridge - 10 years after transplanting from our research nursery here at the U of MN. They grow in the USDA Hardiness Zones of 5-9, going to -20 or -30 F. The Chinese catalpa is a little squatter than the southern catalpa, growing to 20-30 feet. It was a special tree in china because its wood was used to make the bottom of the qin, a traditional Chinese instrument.

 A full grown Chinese catalpa, down near the Stone Arch Bridge in SE Minneapolis

Team Tree under the same, a tree that left our nursery 10 years ago

American Forests is the oldest conservation non-profit organization in the USA. They have a project, started in the 40s to catalog, protect, and preserve the largest trees living in the United States. They pick around 750 champions every year, amazing and awe inspiring giants of arbor culture. The trees include urban trees, but also many giants left untouched in virgin forests. They focus on the biggest and best, but they say on their site that "regardless of size, all trees are champions of the environment."

 One of the trees, a former champion from the year 2010 nominated by MPRB arborist Kevin O'Connor, comes from our very own Hennepin
County. It was a Black Willow, Salix Nigra, with a circumference of 384", 64' tall, and a 73'
spread.
The tree died, and had to be cut down, but it was an amazing specimen. Chad had time to get some cuttings from the tree before it died. They took root, and just like willows are know to do, they are growing quick and wild. With some structural pruning, they are looking great so far. These trees have some very large shoes to fill, but hopefully they can join the ranks of some of Americas largest trees. Pictures of the new champion willows coming soon!




Link to the American Forests Big Tree page, a must for anyone who wants to see some amazing trees:
http://www.americanforests.org/our-programs/bigtree/

Last year, a tornado cause thousands in damages in North Minneapolis in a tragic event still fresh in many citizens minds. Many scars from the tornado are still visible. In Fowell park, many of the trees were destroyed. Last year team tree planted replacements to recover the shade coverage.

Volunteers from the community helped out the recovery work, and Team Tree teamed up with some citizen foresters. The trees went in well, and when we biked over to check up on them, many of them were growing well.

A few of the trees were destroyed during the planting, and Chad was able to replace them by loading up the racks on his cargo bike. They are covered up with black plastic bags on the back.

The trees in the park are doing well, but the damage is still very visible. You can see the older trees, the space between them, and the small trees coming in to take the place of the loss. Hopefully they will be giving shade to park goers for many years in the future.

Team Tree went to Como Golf Course on another bike excursion. Jonathan just bought a new bike trailer, and we loaded it up with some little trees and a few tools, and headed over to the golf course to check up on trees, and replace a few that didn't make it.

When we got there, the turf manager greeted us and let us borrow a golf cart to get around the course. He said there had been a little vandalism recently, but all of it was harmless to the trees. Most of it was obscenities spray painted on tree tubes, and there was a smiley face painted on an elm tree.

The golf course was one of our higher-stress outings, as Jonathan and I often got confused about which way people were hitting their balls, and heard "fore!" a few times. Luckily we didn't get hit, and the turf manager said it comes with the territory. He hasn't taken any serious hits, and that's with a lifetime on the course.

The trees were looking good for the most part, aside from a few dead buckeyes here and there that we replaced. The turf manager said that some of the older trees on the course would have to come out soon, and I was glad we could help out keeping the course well stocked with shade trees.

Least week team tree hit the streets and biked to a few sites to evaluate the trees we planted there earlier. We first went to the intersection of Phalen and Payne where we planted a few rows of trees. This is the second year the trees have been under observation, and we took notes on their crown development, the amount of dead branches, trunk condition, and symmetry.

The "shaka" is a sign of positive reinforcement with hawaiian roots. It is also a convenient measure of new growth.

One "shaka" of growth means a healthy tree!

The trees overall have been doing very well, but they are afflicted by a few new dangers being 

out in the city. Some new problems include salt spray off the road in the winter, leading to motley looking leaves and dead branches. The spray can effect trees over 20' away from the road. Other signs of harm include damage from mowers and weed whips, leaving scars on the base of the trunk, and some minor vandalism. A more unusual issue was the presence of some confused drivers. There is a 45 degree turn at the beginning of the triangular plot, and some people seem to miss it. There were a few trees bearing large scars on their trunks, and one that was completely removed from it's roots, and some tire tracks outlining the path of destruction.

The few trees that died were marked for replacement, and after evaluating and photographing the other trees, we hopped back on our bikes and headed home. It was a good day in the world of urban arboriculture.