How to Attract Beneficial Insects to Your Garden

Beneficial insects can help control the harmful insect population in your garden. Some, like trichogramma wasps that attack such pests as cutworms and cabbage loopers and nematodes that go after root weevils and white grubs, can be purchased from nurseries and gardening catalogs [See Beneficial Insects to Buy for Your Garden.] to be released into your garden. You can, however, forego purchasing bugs by gardening in such a way as to attract beneficial insects to your garden. Following are some methods that you can implement to encourage more of the good bugs to visit your garden.

Grow plants that will attract beneficials to your garden.
Beneficial insects like pollen and nectar, which they feed on until it is time to dine on the harmful insects, which is when those insects arrive in your garden and/or their young hatch. Herbs will really lure the beneficials to your garden. The good bugs particularly like caraway, dill, fennel, lemon balm, and spearmint. (In fact, I have found that all mints in general are great for attracting the beneficial insects while repelling the pests. In fact, whenever I find some bad bugs trying to take hold in one of my gardens, I place a pot of mint in that garden, which more often than not solves the problem.) Another herb that will draw beneficials, especially lady bugs, to your garden is tansy. [For additional information, see The Herb Tansy.] Even some plants generally considered to be weeds, such as dandelions, are good for attracting beneficials. (Plant the dandelions around your fruit trees. See: Dandelion: Herb or Weed?)

Many other flowering plants are also good for attracting the good bugs. Most wildflowers make good choices. Yarrow is good for attracting lacewings, ladybugs, hoverflies, and many others. Cosmos (specifically the white version called Cosmos pinnatus) and zinnias are also good choices, as are bee balm, chrysanthemums, sedums, and rudbeckia. Clovers and other legumes are also particularly attractive to beneficials. Whatever flowers that you choose to plant to attract the good insects, you should try to choose plants that bloom at different times so that you will have something blooming throughout the season.

Supply your beneficial insects with a water supply
You may not think of insects drinking water, but they do. For example, the wasps use the birdbaths around my yard as much as the birds. You can also just put out a small saucer filled with decorative rocks and water. Ponds or water features in the yard can also be a source of water for your good bugs.

Provide shelter
Insects need shelter from high winds and rain, as well as a place to spend the winter. Planting tall perennials and such tall annuals as sunflowers can provide a type of windbreak. In addition, perennials can not only provide food for your beneficial insects but also shelter from the elements and a place to spend the colder months.

Avoid using pesticides
The first impulse that many gardeners have when they are plagued by pests in the garden is to grab the pesticides. Spraying pesticides all over the place can actually do more harm than good. Most such pesticides will indeed rid your garden of the bugs -- both good and bad. The problem is that probably 50% or less of the beneficial insects will return while almost all of the harmful pests will be back. If you must use pesticides, you should try to use those that do as little harm as possible to the beneficial insects.

I use absolutely no chemicals in my yard. Instead, I incorporate the first three practices that I have discussed in this article. As a result, I have noticed a decline in the pest population in my gardens. (This really became apparent when I did some work for a woman in her gardens and was eaten alive by numerous evil bugs that do not plague me in my own yard.) It is much easier -- and more cost-effective -- to get nature to work with you.

References:
Marinelli, Janet, ed. Natural Insect Control: The Ecological Gardener's Guide to Foiling Pests. Brooklyn, NY: Brooklyn Botanic Garden, Inc., 1994.

Rodale, J.I., ed. The Organic Way to Plant Protection. Emmaus, PA: Rodale Press, Inc., 1966.

For lists of more plants to include in your garden, see:
Farmer Fred. Plants That Attract Beneficial Insects.