Mary Meyer, extension horticulturist and professor, University of Minnesota
As a grass researcher and lover of grass, I enjoy and appreciate a lawn. I also know there is great value in a lawn that allows and encourages a diversity of plant species that will benefit pollinators while looking neat and tidy for our neighbors to accept. First of all, let me state that I have had more questions on how to NOT attract bees to lawns, and how to eliminate bee plants (such as creeping Charlie) than on how to attract bees to lawns. When you have young children sitting on the lawn, rolling on the lawn and playing outside, bees can be a problem that you want to avoid. But for adults and taller folks, we can easily avoid bees in lawns. And knowing that bees are vital pollinators that need our help with increased habitat, I urge you to look at your lawn and consider where part of it may become a haven for bees and other important pollinators.
What is a bee lawn?
My definition of a bee lawn is a combination of traditional cool season lawn grasses and other low growing plants that support bees and native pollinators (Photo 1).
This combination must tolerate some mowing and foot traffic. From a distance this combination will look like a lawn, but when you walk on it you see it is much more diverse.
Reasons to foster a bee lawn:
• Plant diversity is good for the environment, can improve soil health and supports a wide variety of insects, birds and wildlife
• Flowering plants provide pollen and nectar for pollinators which will help increase and stabilize their numbers
• Legumes such as clover can increase soil nitrogen and reduce the need for supplemental fertilizer on lawns
• A diversity of plants in your lawn will make it less susceptible to disease, insect or drought damage
Where to grow a bee lawn
Plants that bees love need full sun more than water or fertilizer. If you have a sunny slope that is problematic for mowing, consider making the area a bee lawn and only mowing a few times a year. A few bee plants like Lamium tolerate shade, but are ground covers and are not lawns; most bee plants that will grow in a lawn are sun loving plants.
You may be uncomfortable with this look in your front lawn, especially if you are concerned about the neighbors wondering about your level of lawn maintenance. However, in your back yard it may be aesthetically easier for you to tolerate and allow clover and other legumes and short mint-type plants grow.
If you do need an area for children, decide on which section will best fit children's needs i.e. flat for running and sports, etc.
If you have a vegetable garden, you may want a bee lawn nearby to assist in squash pollination; if you have fruit trees, you may want the ground cover under the trees to become a bee lawn, encouraging pollination for increased fruit set.
Guidelines for Developing a Bee Lawn
Mow your lawn at 3-4", longer grass will withstand more drought and may allow some legumes to begin to grow. Consider mowing once a month, or as needed to maintain the appropriate appearance of a longer lawn.
Over seed your lawn with white and alsike clover. These two species of clover are excellent bee plants. Both are short, can be mowed and produce an abundance of small flowers that bees are fond of. For traditional lawn lovers, white clover (Trifolium repens) and alsike clover (Trifolium hybridum) are weeds. However, both species attract several kinds of bees, including honey bees, and the seeds of white clover are eaten by many birds and waterfowl. Both species grow easily on most soils, and tolerate some mowing and foot traffic. And both fix nitrogen, increasing the nitrogen available for grasses growing nearby.
Reduce or strictly limit the use of herbicides and insecticides. You can selectively kill any broadleaf weeds that you do not want with a spot treatment herbicide. Clover and all other bee friendly plants listed in this article are easily injured and usually killed with herbicides. Bees and insecticides do not co-exist. It is a trade off, so consider the risks each time you are thinking of using either an herbicide or insecticide.
Plant bee's favorite plants: These plants are bee favorites, but are also short and tolerate some mowing and minimal foot traffic: most any of the mints, especially self-heal (Prunella vulgaris), bird's foot trefoil (Lotus corniculatus), and thyme (Thymus spp.). Squill (Scilla siberica) is an early blooming small bulb that can be naturalized in lawns, along with crocus (Crocus spp.) that attract bees early in the spring. Wait a few weeks until the foliage from these bulbs has yellowed before mowing in the spring.
Grasses for bee lawns
Fine fescues are the lowest maintenance grasses: sheep fescue (Festuca ovina), chewing's fescue (Festuca rubra ssp. Fallax), creeping red fescue (Festuca rubra), and hard fescue (Festuca brevipila) are all good low maintenance grasses. These grasses all tolerate low fertility soils, are drought resistant and tend to mound or fall over, providing a cover for bees that nest in the ground. Shady lawn seed mixes are usually fine fescues.
Mow high and just see what grows? This is the 'least work' option and may or may not result in bee plants. You may get a very weedy and unsuitable look with plantain, knotweed and crabgrass, none of which are bee favorites. Bees, however do not discriminate and have no idea what weeds are, they love dandelions and creeping Charlie.
A last word on ground ivy, creeping Charlie (Glechoma hederaceae): bees love this plant and will benefit from your leaving it in your lawn. Most of us know, however, that this aggressive mint can become the lawn if left to grow in low fertility, especially shady, areas. I love it in my backyard bee lawn along with violets (not so good for bees, but larvae food for some butterflies), but in my front yard I prefer grasses and flowering bulbs and keep the ground ivy at bay.
Consider where a bee lawn can fit into your landscape. As conscientious gardeners, we need to support bees and pollinators.
For more information:
The Xerces Society. 2011. Attracting Native Pollinators: Protecting North America's Bees and Butterflies. Storey Publishing
The Bee Lab at the U of MN: http://beelab.umn.edu/
The Xerces Society: http://www.xerces.org/