Gardening for Bees: Why and How
As you lean on your hoe in that lovingly tended, highly productive early August vegetable patch, do you ever think about who else is helping you to get those vegetables to the table? Sometimes unseen, often unheard, paid only in nectar and pollen, those assistants are absolutely essential to the process of turning flowers into fruit and seed. Pollinators, be they beetles, bees, flies, ants, butterflies, hummingbirds, or bats, are responsible for apples, beans, cranberries, squash, tomatoes, sunflowers and hundreds more. Globally, one out of every three mouthfuls of food depends on a pollinator. And pollinators are in trouble.
Bees are the most important pollinators in North America. Since there are no native North American honey bees, the European honey bee (social, lives in colonies, makes honey!) is the species of bee most often raised by North American beekeepers. Since the winter of 2006–2007, unusually large numbers of apparently healthy worker honey bees have abandoned their hives en masse, a phenomenon that has come to be called Colony Collapse Disorder. But focusing on Colony Collapse Disorder, which is real and dramatic and troubling (and imperfectly understood), has in many ways obscured the more powerful fact that honey bees have been in accelerating decline for the last seventy years.
Wild bees are struggling as well, probably more than the honey bees. I suspect that most of us aren’t aware that there are bees other than honey bees and bumble bees, but in fact there are 20,000 species of bees worldwide, 4000 of them found in the United States, 500 native to Minnesota and Wisconsin. Most wild bees live in nests either in the ground or in holes in dead wood, stone walls, hollow stems, or other crevices in your garden. They are docile and hardly ever sting. Although they don’t make honey, they are terrific pollinators because they’ve evolved alongside the flowers that they pollinate. But wild bees’ numbers have been dropping, too. Some bumble bee species are on the verge of extinction.
What has gone wrong?
Over the last 50 years, almost every change we have made as a society to how we live and how we farm has been unfriendly to bees. We have more concrete, more lawns, more pesticides, and more giant farms growing corn and soybeans. We have fewer weeds and fewer flowers. As individuals who care about the health of bees, there are some things we can’t do much about (bee diseases, bee genetics) but as gardeners we have a powerful tool: that little piece of ground we call our own back yard. Make some simple changes, and then persuade your neighbor and their neighbor to do the same. It will make a difference.
What you can do
- Minimize your pesticide use. Learn to accept imperfection. Hand pull unwanted plants. Think of the “weeds” in your lawn (clover, chickweed, violets) as “grass companions.” Read about integrated pest management.
- Plant flowers that appeal to bees: flowers with landing platforms, single flowers, particularly in white, yellow, or blue. (Bees see in the ultraviolet range, which means they don’t see red.) Be slow to deadhead because fading blooms still have nectar. Plant in clumps.
- Plant natives. This is an important one. Studies of bumble bees show that they prefer natives 4:1 over introduced plants. Dense stands of native flowers give “more bang for the buzz.”
- Plant for succession (this is good for you as well as the bees). Try to have at least three things flowering in your garden at all times; critical times are early spring and late fall, think squill and crocuses, goldenrod and asters. Plan your yard vertically (canopy, understory, shrubs, ground layer) to fit in more plants. Reduce or get rid of your lawn.
- Include some nesting space for wild bees. Sixty to seventy percent are ground nesters; just leave an area of exposed, undisturbed soil. No mulch, sorry. Thirty to forty percent of native bees are cavity nesters; except for the carpenter bees, native bees can’t excavate their own holes, so they need ready-made tunnels. Consider a bee house made of either an untreated, drilled wood block or hollow sticks. Leave rotting dead wood in your yard.
- Read. Educate yourself. Educate your neighbor (if your neighbor is using pesticides, they’re ending up in your yard).
- Consider becoming a beekeeper. Really, why not? Find information at www.beesquad.umn.edu.
- Support local research. As gardeners, we are lucky to have a world class bee lab on the Saint Paul campus of the University of Minnesota, where the goal is to “get bees back on their own six feet.” Run by Marla Spivak, a MacArthur fellow and professor of Entomology at the U, the bee lab runs classes, does research, works with beekeepers, and has big plans for the future.
What About Wasps?
Wasps are different from bees. Most wasps are meat-eating predators that feed on insects, making them beneficial in the garden. They have little to do with pollination (one notable exception: the tiny fig wasp which is the sole pollinator of some kinds of figs).
Another note about wasps: Paper wasps, yellow jackets and hornets are types of wasps. If you have ever been stung at a picnic, it was probably by a wasp, not a bee. Bees rarely sting people when foraging on flowers, but yellow jackets in August—watch out!
www.beelab.umn.edu—Researchers from the U of M will be on hand in the Garden Fair to answer questions about bees and plants for bee habitat. See page 4 of the catalog for schedule.
www.queenofthesun.com—a documentary film about bee colony collapse disorder
Planting for Bees
Native Wild Flowers
Joe Pye Weed—Eupatorium
Purple Prairie Clover—Dalea
Saint John’s Wort—Hypericum
Poppies—Papaver (not red)
Once started, most annuals will contine blooming until frost.
Baby Blue Eyes—Nemophila
Bee’s Friend—Phacelia (Seed Savers)
Sunflower—Helianthus (Seed Savers)
Shrubs and Trees
Dogwood—Cornus (Cornelian Cherry*, Pagoda and Red Twig)
Dandelions and crocus are also great early flowers for bees.