The majority of insects either have no effect on the garden or are actually beneficial, providing pollination or pest control services. For example, good "bugs" such as hoverflies, minute pirate bugs ladybugs, bigeyed bugs, lacewings and spiders dine voraciously on garden pests like aphids, thrips, mealybugs, flea beetles, gypsy moths, corn borers and coddling moths.
But beneficial insects, like other living things, need habitats as well as sources of food and water, throughout the course of their lives. By providing a diversity of plants to supply pollen, nectar, food and shelter over the growing season, we secure their expert pest-eating services.
Research shows that these useful predatory insects are especially attracted to common flowering plants, garden herbs and even some weeds. Cosmos, marigolds, sweet alyssum, yarrow and sunflowers encourage beneficial predatory insects. Herbs such as coriander, parsley, dill, fennel, and mustards as well as such so-called weeds as dandelions, clovers, Queen Anne's Lace and goldenrods also attract and nourish these good "bugs." Even buckwheat and winter rye cover crops can help eliminate pests while they control weeds and build soil. Leave these plants in the garden for a longer time without mowing or plowing them under so that the good insects can complete their life cycles.
Despite increasing evidence of the value of a diversity of plants, the current culture leans in the opposite direction with lawn and farm monocultures carefully maintained by mowing, plowing and the use of herbicides. Unfortunately, insecticides often kill off more good bugs than bad ones, leaving pesticide-resistant insects with no natural enemies to control them. Some pests are necessary to attract and feed the predators.
Of course, it always pays to take the basic steps to minimize pest pressure: create and maintain healthy soil, plant appropriate varieties at the right time, rotate crops and keep your eyes open for troublesome insects like the Colorado Potato and Japanese Beetles.
However, more and more organic gardeners and farmers find that by maintaining a diversity of plants in the vicinity of their crops, they have much less trouble with insect pests.
I'm Bill Duesing, Living on the Earth.
This page and its contents are copyright