If You Encourage Them, They Will Come!
By now we’ve all heard the news: pollinators are in trouble. The White House has established a Pollinator Health Task Force to integrate the needs of bees and butterflies into land management plans. The Department of Transportation is seeking to increase pollinator habitat along highways.
When it comes to the built-up cities, it’s up to urban residents to provide nectar, pollen, and nesting options. Every person with access to a sunny fire escape, patio or tiny backyard plot can make a difference.
Nearly 75% of all plants on earth require animals for pollination.
The Xerces Society
The Good News is . . .
A study by Rosemary Malfi, University of Virginia, and Neal Williams, UC Davis, showed that native bumblebees, which are among our most important pollinators, thrive in urban and suburban environments. In fact, their abundance has been shown to actually increase with increased development. Besides the ubiquitous bumblebee, researchers counted around 50 other types of bees in a five-year survey of community gardens in New York City. Carpenter bees, leaf cutters, borer bees, mason bees, sweat bees and others were drawn by the flowers and shrubs planted by urban gardeners.
The flip side of this, however, is the relative lack of abundance of some other wild bee species, particularly those that depend on early spring bloomers, or nest in bare soil.
Pots for Pollinators
Plant flowers in raised beds and containers throughout your own urban garden, and pollinators will find them. This has been proved in the Battery Rooftop Garden, a 35th floor New York garden that is isolated from life on the ground and pummeled by harsh winds. Despite the extreme altitude the garden is inhabited by a diversity of pollinators and other beneficial insects, an abundance that has been attributed to high floral diversity. If they can make it there, they can make it anywhere!
If we’re to support urban agriculture, we must support urban bees!
The Xerces Society
1. Be Prepared for Pollinators in Spring.
It’s especially important to plant spring-blooming flowers if there are no fruit trees or early-blooming shrubs in the vicinity of your urban garden. Columbine, California poppies, sweet alyssum, larkspur, bachelor’s buttons, clarkia, cerinthe, and cilantro will sustain bumblebees, miner bees, and other native pollinators until summer nectar and pollen sources become plentiful.
2. Plants Flowers in Summer
Group plants of the same species in clusters, and provide a diversity of species in your garden. Zinnias, coreopsis, cosmos, sunflowers, tithonia, cchinacea, and herbs that flower, such as thyme, basil, oregano, and arugula will keep bees busy through the summer and into fall.
3. Avoid Pesticides
Handpick pests or use non-toxic products such as horticultural oils or soap sprays. Particularly avoid broad-spectrum pesticides, even organic ones such as pyrethrin.
4. Offer Water and Nesting Options
Bumblebees often build nests in abandoned rodent nests. Other cavity nesters prefer rotting logs or stumps, or the soft pithy centers of elderberry trees or sunflower stems. This means “neatening up” can deprive bees of prime nesting sites! (Read Don’t Clean Up Your Garden in the Fall to understand why that is so very bad for the environment.)
Bees also need access to clean, shallow water.
5. Leave Spots of Undisturbed Soil
Bees with the fewer housing opportunities in the urban garden are ground-nesting native bees. Set aside an area of the garden where you will not cultivate the soil, as bees need direct access to the soil surface to construct their underground tunnels. Six to 36-plus inches (15 to 90 cm) under the surface, these narrow tunnels lead to small chambers (brood cells) where next year’s bees will develop.
Frequent Fliers in the Urban Garden
Planting colorful flowers such as zinnias, scarlet runner beans and cosmos will attract pollinators to your garden. Studies have shown that they will stay and pollinate your crops also, ensuring a good harvest.
Most pollinators commonly seen in the urban garden are cavity nesters and many are solitary bees rather than hive dwellers. Some can be mistaken for wasps or flies.
Don’t forget the hover flies!
I will encourage all bees and pollinators, except the Carpenter Bees. They have bored many holes in our deck and do a lot of damage!