Jane Says: Make Your Garden a Sanctuary for Bees
The mysterious, widespread outbreak of what is called colony collapse disorder (CCD) has been a source of grave concern to scientists, beekeepers, and commercial farmers since 2006, when worker bees started abandoning their queens and hives in record numbers.
Researchers estimate that almost one-third of all honeybee colonies in the United States have disappeared, and we all know why this situation has catastrophic consequences: Honeybees are commercial agriculture’s default pollinator. Almost all flowering plants require animals for pollination, and even self-pollinating crops, such as tomatoes, peppers, and eggplants (which all happen to be nightshades), generally produce higher-quality fruit when cross-pollinated by bees, which journey from farm to farm, and region to region in trucks, contributing more than $15 billion to crop production in the U.S.
The precise cause of CCD is difficult to nail down amid preexisting stressors, including parasites (such as the varroa mite), sublethal effects of pesticides (such as neonicotinoids), viral diseases, malnutrition, and the ever-increasing loss of habitat to housing and monoculture. Of potential significance is last year’s discovery, by researchers from the USDA Research Service and China's Academy of Agricultural Science and recently published in the American Society for Microbiology's open-access journal, mBio, that tobacco ringspot virus, a pathogen that typically infects plants, is now spreading inside bees.
In other words, bees need TLC, not TRSV, and making your garden a bee-friendly one is a great way to do your bit; even a modest patch or container garden will provide important habitat for pollinators. Although the European honeybee (Apis mellifera) and bumblebee (Bombus spp.) are what most of us conjure when we think of bees, there are about 4,000 species native to the U.S.; you’ll find 1,500 species in California alone, according to Scott Hoffman Black, executive director of the Xerces Society, an invertebrate conservation organization based in Portland, Ore.
Choose the Right Plants
Bees eat nectar (which is loaded with sugar and thus is bees’ main source of energy) and pollen (which provides protein and fats). To provide food for bees for most of the year, plant an array of species that will bloom in succession from early spring, when bees first emerge from their nests, until they return to them in late fall. Because bee species have different tongue lengths (adaptations to different flowers), a variety of flower shapes will attract the greatest diversity of bees. There’s a helpful chart of what plants attract long-tongued and short-tongued bees (as well as other good information) at the University of Illinois Beespotter website.
They also need to be the right color. “Bees are attracted to white, yellow, blue or purple flowers,” wrote Renae Anderson in a USDA blog post. “Bees also need a variety of sizes, ranging from big sturdy flowers for the bumble bees to small delicate ones for the sweat bees.”
As a general rule, native plants are better at attracting native bees, but older flowers and herbs (when blooming) such as cosmos, sunflowers, hollyhocks, astors, zinnias, daisies, cornflowers, dahlias, calendulas, coneflowers (echinacea), lavender, rosemary, thyme, mint, basil, borage, marjoram, chives, and lemon balm are also good bee attractors. Avoid new hybrids that are bred for their showy looks at the expense of nectar or pollen.
If you’re wondering about planting an exotic butterfly bush (Buddleia davidii, Buddleja davidii), you should know that even though it produces lots of nectar, it often can’t produce enough for the entire life cycle of butterflies and bees. And if you already have one, you should cut it close to the ground in late winter or early spring. Buddleia blooms on new wood, and even if a winter is mild enough for the stems to survive, prune it drastically anyway to stimulate abundant growth and flowering. For more on the planting and care of buddleia—or just about any other plant you’re interested in—pay a virtual visit to the Missouri Botanical Garden, a world-class resource for gardeners.
Vegetables that attract bees when flowering include melons, cucumbers, onions, squash, and pumpkins. To help determine what flowering plants will flourish in your garden and what the timing of their blooming will be, consult the USDA plant hardiness zone map, published by the National Arboretum. And Botanical Interests, a purveyor of organic and heirloom seeds, suggests you contact your local nursery or independent garden center, your state's native plant society, or your local cooperative extension office for a list of native plants in your area.
Buy Organic or Untreated Seeds
Grow your plants from untreated seeds in organic potting soil, or purchase organic plant starts. The Friends of the Earth conducted a pilot study to determine the extent of neonicotinoid contamination of common nursery plants purchased at retail garden centers (including Home Depot, Lowe’s, and Orchard Supply Hardware) in cities across the U.S. It concluded, “The findings indicate that bee-friendly nursery plants sold at U.S. retailers may contain systemic pesticides at levels that are high enough to cause adverse effects on bees and other pollinators—with no warning to consumers.” That said, it’s worth noting that it isn’t clear how big a part neonics play in CCD. Although the EU has banned the use of those pesticides on crops attractive to bees, when the U.K.’s Department for Environment, Food and Rural Affairs reevaluated three recent studies, it found that much of the lab-based data was based on doses and application methods that farmers don’t use.
Seed purveyor Botanical Interests advises planting flowers in clusters, because “larger groupings of flowers (instead of sporadically spaced single plants) attract more bees.” Planting in sunny areas is key, as “bees prefer to forage in sunny, protected areas where they won't be bombarded by wind. Sunny spots produce the most prolific flowers as well.”
“If you intersperse some flowers that bees love with your veggies,” according to Botanical Interests, “it will help increase pollination of your vegetables for a better crop.” Another tip I haven’t seen elsewhere is to allow some vegetables and herbs to bolt in the fall, thus providing late-season food for bees. If you’re a gardener who inadvertently lets the basil or chives go to seed, then stop feeling guilty and bask instead in a virtuous glow.
Lastly, try not to put bee-friendly plants in high-traffic areas, and (duh) wear shoes.
Create Nest Sites
A little untidiness goes a long way in helping bees flourish. If you can keep a wild space—where grasses and weeds remain undisturbed all year long—along a border or near the garden, that will provide nesting material and shelter to wild bees. And instead of cultivating every inch of garden space, leave one patch of soil alone and uncovered with mulch. About 60 percent of native bees, which are solitary creatures, nest in the ground, about a foot under the soil. Other species nest in old wood and cavities. Visit the Xerces Society for a thorough discussion of how to add nest sites to any type of green space.
And like all living creatures, bees need a source of freshwater, but according to the Vancouver-based David Suzuki Foundation, most can’t land in a conventional birdbath without crashing. Instead, line a shallow bowl or plate with rocks. Add water, but leave the rocks exposed to serve as landing pads. Then place the bath at ground level in the garden. “Put it near ‘problem plants’—those that get aphids, for example—and the beneficial insects that come to drink will look after them. Refresh the water daily, adding just enough to evaporate by day’s end.”
This sounds like a no-brainer until a swarm of yellow jackets, for instance, takes over your patio and terrorizes you or your children. They’re far more easily provoked than bees; they can also sting more than once. If you must spray, practicing integrated pest management is the way to go. Most important, as any horticulturalist will tell you, read the label and follow the directions to the letter.
Books and Websites to Take You Further
Attracting Native Pollinators: Protecting North America’s Bees and Butterflies, by Eric Mader, Matthew Shepherd, Mace Vaughan, and Scott Black (all staff members of the Xerces Society) in collaboration with Gretchen LeBuhn, a San Francisco State University botanist and director of the Great Sunflower Project (Storey Publishing, 2011).
A Sting in the Tale: My Adventures With Bumblebees, by Dave Goulson, one of Britain’s most respected bee conservationists (Jonathan Cape, 2013).
Bumble Bee Watch: At this website, citizen scientists can help build a comprehensive picture of where bumble bees—pollinators extraordinaire because they are so big and hairy—are thriving and where they need help.