By creating a garden that attracts a range of pollinators, students can provide vital oases amidst seas of buildings and concrete. They can, in turn, use these living laboratories to explore plants, animal visitors, and the ways in which the threads of life connect. Here are some general guidelines for cultivating gardens that appeal to these important plant partners.
Plant plenty of nectar- and pollen-rich flowers. Use as many native plants as possible, since local plants and pollinators are more likely to be adapted to one another. Also shoot for old-fashioned varieties. Although hybrid flowers are bred to look or smell nice for humans, they often don't provide much accessible nectar or pollen for animal partners.
Include a variety of flowers that bloom throughout the season. By doing so, you will accommodate different pollinators' preferences and provide a sequence of pollen and nectar sources throughout different stages of the life cycle.
Try to get flowers with a range of shapes and sizes. Trumpet or cup-shaped flowers, such as cardinal flower, honeysuckle, and bee balm, attract a wide range of pollinators. Pollinators with shorter tongues, such as small native bees and wasps, feed on tightly packed clusters of small flowers, such as those found on milkweed, zinnia, phlox, and mint. Hummingbirds feed on red, purple, or orange flowers with lots of nectar, such as bee balm, fuschia, sage, and nasturtium.
Include food sources (host plants) and overwintering places for eggs and larvae. Allow a section of your schoolyard to revert to wild grasses, weeds, and wildflowers (e.g., milkweed and Queen Anne's lace), and plant dill and parsley for larvae.
Provide water. Pollinators such as butterflies can gather and sip at shallow pools, mud puddles, and birdbaths, and bees and wasps to build nests.
Avoid using pesticides and herbicides. Many can be harmful to pollinators as well as pests. Herbicides may wipe out key plants (weeds) that are important for pollinators' food mix. If you feel that you must control pests, judiciously use homemade remedies such as garlic spray, or pesticides derived from plants or microbes. Apply them only after sundown, when most pollinators have stopped their rounds.
Provide nesting sites and materials. Leave cut plant stems exposed, turn flowerpots with bottom holes upside down, leave twigs and brush in small piles, create mud puddles, or put out pieces of string or other light fibers.
Butterfly gardens are a favorite and enticing schoolyard theme, but these winged beauties, who help move pollen from male to female flowers so fertilization and seed production can occur, are hardly the only such partners. In fact, thousands of different animal species help pollinate plants, including bees of all sizes, tiny wasps, moths, flies, bats, and hummingbirds.
The role of pollinators is often taken for granted, but it is more important than many of us recognize. These creatures are vital to a healthy ecosystem and to production of many of the crops that feed, clothe, and otherwise support human existence. Without them, most flowering plants wouldn't be able to produce fruits and seeds to create the next generation. Some plants, like daisies and other Composite flowers, offer lots of easily accessible nectar that attracts a wide range of pollinators. Other plants, such as certain orchid species, may depend on a single pollinator. If a plant is dependent on a single or limited number of pollinators whose numbers dwindle, the plant's future will be in jeopardy. The same is true of pollinators dependent on a limited number of plant types. Plant scientists are concerned about humans' role in weakening pollinator/plant relationships. The overuse of pesticides, which often kill beneficial pollinators as well as intended pests, is one factor. Another factor, particularly serious for migrating pollinators such as monarch butterflies, is land fragmentation that results largely from development. Isolated plants can't attract a variety of pollinators or visitors frequent enough to sustain the plants and ultimately their partners.