Different pollinators visit different flowers, depending on their size, the length of their tongue, their color vision, their sense of smell, and other factors. Therefore one of the most effective things you can do to promote healthy and diverse pollinator populations is provide a variety of flowering plants.
What to Plant
- Choose native species whenever possible. Some non-native garden plants and even common weeds are important foraging resources for generalist pollinators where natives are absent. But some pollinators feed only on specific native plants. And for overall ecosystem health, native plants have a much higher conservation value. According to the Metropolitan Flora Project, an initiative of the Brooklyn Botanic Garden, over 50 native plant species are locally extinct or nearing elimination from the New York metropolitan region. It is more important than ever to conserve native plants and their pollinators in urban areas.
- Plant large drifts or clumps of flowers of the same species rather than scattering them here and there throughout landscape. Most bees tend to forage on one species at a time — which is better for the plant, too, as it ensures that the pollen will be spread among plants of the same species. Keeping food resources close together also makes it easier for bees to find pollen and nectar and get back to provision their nest without expending energy traveling great distances, as does providing the flowers they need in close proximity to their nesting habitat.
- To ensure a steady food supply for resident and migrating pollinators, it’s also important to have plants in flower from April through October.
Bees can see a wide range of colors, but primarily those at the blue end of the spectrum, including ultraviolet. For this reason, the flowers they favor are typically shades of blue and purple, but also white or yellow. Bees can recognize pattern as well as color, and the flowers they visit frequently have “nectar guides” on their petals—radiating lines or concentric circles, often UV, that guide the insect into the flower. In addition, bee flowers are often sweetly fragrant.
Some flowers, like our native blue lupine, are particularly suited for pollination by bumble bees, with modified lower petals that serve as sturdy landing pads. Other bee plants native to the New York metropolitan region include blue lobelia, blueberries, sweet pepperbush, and blazing stars. For more plants, see the Xerces Society publications Northeast Native Plants for Bees and Mid-Atlantic Plants for Native Bees.
Although the vast majority of bees in the metropolitan area are generalists that feed on a wide variety of flowers, about 20 percent feed on species in only one plant family, or even a single species. For information on the plants favored by these specialist bees, see here.
Butterflies are attracted to many colors. The flowers they visit for nectar are usually found in clusters to provide a good landing platform for the butterflies, which walk around on the flower clusters probing for nectar with their strawlike tongues. Butterfly blooms have a floral tube that is tailored to the length of the particular species’ tongue.
Butterflies have a weak sense of smell, and the blooms they visit are typically odorless.
Native nectar plants for butterflies include New England aster, mountain mint, goldenrods, and joe-pye weed. For more nectar plants, see the Butterfly Site list, organized by the butterflies that use them. The North American Butterfly Association website has a list of native garden plants that are good for butterflies.
Nocturnal moths and other night-flying pollinators are attracted to white or pale-colored flowers that are visible in the dark; in fact, some of these blossoms open only at night. The flowers often have deep tubes to match the length of the moth’s tongue. Because the moths hover, the flowers they feed on have no landing platform.
Moths have a great sense of smell, so the flowers they favor have a strong, sweet scent, especially useful for luring pollinators at night.
Native plants in our region that are pollinated by moths include sacred datura and evening primrose.
Most birds can see the same colors as humans, but hummingbirds tend to favor red or orange blooms. The flowers are typically long and tubular, adapted for a hummingbird’s long, narrow bill and tongue, and they often (although not always) point downward so that the hovering hummingbirds have easy access.
Because hummingbirds, unlike many insects, have a poor sense of smell, the flowers they visit usually are not fragrant.
Wild columbine, cardinal flower, red bee balm, and coral honeysuckle are a few hummingbird-pollinated native plants. A longer list of plants is here.
Flies can see a wide range of colors, but primarily whites and yellows. Some, like syrphid flies, look a lot like bees and visit bee flowers. Other flies pollinate early spring wildflowers, fancying brown or purple blossoms that resemble rotting flesh and emit the essence of carrion or dung. Among the preferred flowers of these flies are the aptly named skunk cabbage, which has a mottled purple bract called a spathe that partially surrounds tiny flowers massed together along a fleshy pole called a spadix. Other arums such as jack-in-the-pulpit, red trillium (called “stinking Benjamin” by early naturalists), and pawpaw are also native fly-pollinated plants.
Special Food Resources
Some butterflies, such as commas and mourning cloaks, are attracted to rotting fruit and will feed on watermelon or banana pieces placed outside in summer. (This may also attract wasps.) See the NABA website link for details on butterfly feeders.
Many pollinators require water or mineral salts, so providing areas of moist soil can be beneficial. One easy way to do this is by placing a water-filled plastic gallon jug with pin pricks in bare soil.