By Susan Albert
Without realizing it, many of us already practice elements of “green” gardening. For example I have a compost heap, leave grass clippings on the lawn, and recycle and repurpose what I can. Others catch rain runoff in barrels, grow their own food, or use solar lighting in the yard instead of electric.
Another way to help conserve the environment is reduce or eliminate pesticides in the garden. And it’s easier than you might think. Let nature rid your garden of aphids, spider mites, leafhoppers and other undesirables by attracting beneficial insects to your yard.
For example I grow several varieties of milkweed to attract monarch butterflies. Tropical milkweed (Asclepias curassavica) attracts a lot of yellowish-orange aphids, but I just ignore them, and in a few days they are all gone. I never see which insects dined on the aphids, but I strongly believe they were ladybugs.
Beneficial insects, often referred to as “the good bugs,” are predators and parasitoids. Predators, such as lady beetles and their larvae (pictured), seek out and consume aphids, leafhoppers and spider mites. Parasitoids, which include tachinid flies or braconid wasps, lay eggs on insect hosts—often cutworms, armyworms, looper caterpillars or tomato hornworms—and, upon hatching, prey on them.
The best way to encourage natural predators is to create a hospitable environment, with a wide array of annuals, perennials, shrubs and trees, both deciduous and evergreen. Here are more tips to encourage beneficial insects in the garden:
Grow plants rich in pollen or nectar. These varieties, including natives, provide alternate food sources for the beneficials when insect populations are low. Favorites include gaillardia (pictured), coneflower, coreopsis, sweet alyssum, milkweed, marigold, aster, sunflower, fennel, dill, Queen Anne’s lace and mustards.
Avoid using insecticides to kill specific pests. Insecticides not only kill your intended pests but also the beneficial insects at work in the garden. If the pest numbers are out of control, consider low-impact insecticidal soaps or horticultural oils.
Find out who the pests really are before taking action. Pictured is a frequent caterpillar on fennel, parsley, rue and dill. But that is the larva of the beautiful Eastern Black Swallowtail butterfly. Consider planting extra herbs to share.
As an added bonus, providing nectar and pollen plants also attracts pollinators, such as bees and butterflies, not to mention acrobatic hummingbirds!