We gardeners are by nature control freaks, determined to impose our will on our gardens.
We´re always messing around; rarely content to leave nature alone, we scurry here and there, staking, weeding, spraying, watering, fertilizing.
Insects trigger many a gardener´s control efforts. According to Eric Grissell in his book Insects and Gardens, In Pursuit of A Garden Ecology, insects worldwide weigh in at an estimated 27 billion tons, outweighing the human population by about six times. Obviously, insects outnumber us by vastly greater numbers yet. No wonder we gardeners sometimes feel put upon.
ALL NATURE IS INTERCONNECTED. Troublesome or not, insects are truly an essential part of a garden´s structure. “Insects are the little things that run the word,” according to well-known entomologist, Edward Wilson.
Unfortunately the diversity of insects and other creepy crawlies we commonly call bugs suffers as meadows, forests, and small farms give way to paved roads and housing developments. Acre upon acre of single crops grow in today´s large agricultural tracts, further reducing insect diversity.
To make matters worse, pesticide use has skyrocketed creating further trouble in the bug world. Insecticides can breed resistance in the very bugs we are trying to eliminate. And, insecticides often kill the so-called “good bugs” that prey on garden pests, giving “bad bugs” the opportunity to rebound in even greater numbers. Herbicides and fertilizers can have a similar effect on ground dwelling insects, worms, and other soil life.
IT´S A BUG EAT BUG WORLD. To try to banish insects and other garden bugs is to “begin a skirmish that leads to incessant warfare…unwise, unwinnable, and virtually unnecessary,” warns Dr. Grissell. Gardens depend on bugs to feed upon each other; to pollinate flowers and crops; to nourish birds, bats, frogs, lizards, and other garden creatures; to scavenge garden wastes; and to aerate and replenish the soil. Without bugs, our gardens would come to a near standstill.
Most gardeners are familiar with a few beneficial insects—the honeybee, lady beetle (ladybug), and perhaps lace wings or soldier beetles. Actually, a huge number of bugs are pollinators and/or predators or parasites of numerous other garden bugs. Some, like praying mantids and various spiders, chow down on many different victims, while certain tiny parasitic wasps stick to a very limited menu.
REBUGGING YOUR YARD. By becoming more permissive, less controlling of our gardens and our bugs, we have a much better chance of a balanced, naturalistic garden. Rebugging is good not only for our yards but reduces headaches for the gardener too.
Arriving at a natural balance between beneficials and pests doesn´t happen overnight; you might not see the full effect for several years since you must first build up a reservoir of beneficial insects and other creatures.
To start, use the least pesticides possible. Beneficials can be especially vulnerable to chemical assault. Often the best approach is simply to leave the pests alone and let nature deal with them.
Consider choosing a plant, or better yet a group of plants, on which you use no chemicals at all to give beneficials a chance to build up. In the remainder of your yard, identify pest problems before you act; no shotgun treatments! Then choose the least toxic treatment to do the job. (This is called Integrated Pest Management.) If you need help identifying the problem or the treatment, call the Master Gardener office at 209-533-9696 or visit University of California´s Pest Notes: http://www.ipm.ucdavis.edumegarden.html.
Once you have identified your target, here are some less toxic approaches to try. You can squash aphids on new growth and on rose buds by gently pinching and rubbing the affected area. A hard spray of water, including under the leaves, will discourage aphids, white flies, and spider mites. Spraying with horticultural soap deters aphids, white flies, spider mites, mealy bugs, and a few other pests. Zap caterpillars, including tomato hornworms, with Bacillus thuringiensis (Bt) available in garden centers. Repeat as needed. (Note: Bt will kill ALL caterpillars, including butterfly larvae. A community member brought in willow twigs and leaves thick with “worms,” wanting to know if they were “bad” and how to get rid of them. Upon identification, they were discovered to be the larvae of the darkly beautiful Mourning Cloak butterfly. Once again, know your target.)
Don´t use ant spray even though ants will protect sweet honeydew-producing pests like aphids, scale, and mealy bugs. Instead target ants only by placing ant traps near their trails; if ineffective, try a bait with a different active ingredient. Build up your soil and reduce herbicides by using an organic mulch like compost, aged barnyard manure, or shredded leaves.
Next, work toward a diversity of plants that supports different kinds of insects. Consider replacing your most troublesome plants with tougher candidates including some California natives. Natives have survived though the centuries and often are more supportive of beneficial insects and other wildlife. Also attract beneficials with simple, cottage garden flowers like sweet alyssum, cosmos, black-eyed Susans, sunflowers, fennel, yarrow, and tansy.
Perhaps we can all take life a little easier; become a little less controlling in our yards; and help bridge the gap between our gardens and nature.
Master Gardener Vera Strader has practiced Integrated Pest Management in her Sonora garden for eight years. Each year more and more wildlife makes a home in her yard.