Special to the OBSERVER
We can thank pollinators for one in three mouthfuls of food and drink everything from coffee and chocolate to most fruits and many vegetables - in our diet. Pollination is also critical for many of the animal products we consume, including dairy products, beef, pork and poultry. These animals consume insect-pollinated legumes such as alfalfa and clover at some time during their growth. When we start to think about what we ate yesterday for breakfast, lunch, and dinner, we start to understand the importance of pollinators in our own diets.
Pollination is the transfer of pollen from anthers to stigma. Many plants need pollen from a different plant of the same species for fertilization to take place. Pollination is a symbiotic relationship. Both the plant and the pollinator benefit from the arrangement. The plant gains the service of the pollinator to move pollen from one flower to another flower of the same species. The flower provides a food source to the visiting pollinator as nectar or pollen.
Many animals serve important roles as pollinators. In some habitats, bats and other small mammals, birds, reptiles and even larger mammals serve as pollinators. The insect world has many diverse groups of pollinators, including butterflies, flies, moths, wasps, beetles, and bees. Flowers and insects have co-evolved to facilitate pollination. Flowers have evolved colors, scents, shapes and patterns to attract insect pollinators.
Pollinators are under threat from a variety of stresses (including habitat loss, pests, pesticides and climate change), but gardeners can make a difference in their own gardens. With a bit of knowledge and effort, gardeners can select practices that help pollinators.
Insect pollinators, like all living organisms, have basic needs for food, water, shelter (cover) for nesting and overwintering, travel corridors, safety, and space in a suitable arrangement. Consider a plant's attractiveness to bees as well as the beauty it brings to the garden when selecting garden additions.
To keep pollinators in the landscape:
Offer a continual source of food flowers throughout the season. Bees benefit from early blooming flowers to provide a food source in spring, just when they emerge from a long winter. Maple and willow can provide an important early source of food. Mid-summer can be another time with fewer flowers in bloom, so consider garden plants that can provide a food source in the heat of summer. Late season flowers such as asters and goldenrod offer food to help pollinators make a healthy transition to winter.
Bold masses of color can help pollinators find the garden. Research suggests that planting in clumps of at least 3 feet are more attractive to pollinators than randomly dispersed, smaller clumps and pollinators use less energy foraging when many flowers are close together.
An abundance of different kinds of flowers will appeal to a variety of pollinators, and to the gardener! Bee and butterfly diversity is maximized when 15 to 25 flower species are present.
Many native shrubs provide a good food source for pollinators and deserve a spot in the garden. Experiment with some of these, but remember to put the "right plant in the right place" to keep plants healthy and help them resist pest problems.
Butterflies and other insects may be less likely to visit the garden in a windy, exposed site. Use plantings or structures such as fences and windbreaks to make the garden more appealing.
Having a simple water source, such as a bird bath, shallow bowl or dripping fountain provides an important resource for many garden visitors, not just insects.
Pesticides can impact bee populations in a variety of ways. They can kill bees directly, or change their behavior or reproductive potential. Some chemicals make bees more susceptible to viruses. These effects can be caused by fungicides or herbicides, not just insecticides. Chemical additives to pesticide products can also negatively affect bee biology. Consider bee health when deciding if a pesticide is necessary.
One of the additional benefits of pollinator conservation is that many of the same pollen and nectar sources that support native bees also support many predatory and parasitoid insects. Plants in the carrot, aster, mustard and legume family are particularly attractive to beneficial insects, including cilantro, cosmos, alyssum and vetch.
To encourage wood-nesting, ground and bumble bees:
Leave or add snags, stumps and brush piles.
Plant shrubs with hollow or pithy stems, such as cane fruit and elderberry.
Consider adding artificial nests to provide habitat.
Bumble bees tend to prefer to nest in undisturbed areas, which are often rather messy (brush piles, compost piles, unmown grassy areas). Include some undisturbed areas in an out-of-the-way part of the yard for bumble bees.
Recognize that existing natural patches of bare ground may be valuable to native ground bees. Provide habitat by allowing some areas with bare soil, especially on sandy, south-facing sites.
Thank a pollinator this week by selecting and planting a species they love, for a great list go online to "Selecting Plants for Pollinators."
Cornell University Cooperative Extension Colleen Cavagna, Community Educator