Chemical warfare is not the answer to the tiny invaders of your garden


May 13, 1992|By Susan McGrath | Susan McGrath,Los Angeles Times Syndicate

Some years ago, when I was living in a garret in Washington, D.C., I had a yen to do a little gardening. So I scratched out a small plot in the parking lot and planted the one vegetable you simply couldn't find in edible form in any grocery store in the District of Columbia -- spinach.

Pretty soon, my spinach plants broke ground and unfurled their heavenly leaves, so green and fresh you were tempted to lie down in the garden and eat them on the spot.

Well, I didn't eat them, but something else did: loathsome fat white larva. They tunneled through my beautiful green leaves, then departed, leaving me with the sick feeling of someone whose apartment has been burgled.

Not knowing, in those days, whom to call for a house fire, let alone loathsome spinach-eating larva, I called the U.S. Department of Agriculture. Myriad phone transfers later, a laconic bureaucrat drawled "Diazinon."

"What's that?" I asked.

"A pesticide that'll kill those leaf miners," he said.

"A pesticide?" I warbled. "On my spinach? But is that safe?"

"Well, I wouldn't eat the spinach right away. I'd give it a few days."

"What about birds, and other insects and earthworms?"

"It'll kill 'em."

My spinach-growing days were over. I didn't know much about pesticides, but I knew I didn't want to spray diazinon on my spinach.

Today, I know a little more about pesticides. I know that diazinon has been banned from golf courses and sod farms because so many geese and ducks -- thousands -- have keeled over while grazing on the sprayed grass. I also know that you are still free to fling the stuff around on your own yard. Wildfowl aren't likely to land on it, but any unlucky songbirds passing through will bite the dust. So will the bees that pollinate your plants, the earthworms that turn your soil, the lacewings that eat your aphids and the tiny wasps that wipe out your yucky hornworms and ear worms.

Here are three other things I know about garden chemicals:

* Of the 34 chemicals most widely used in pesticides, only two have been completely cleared by the Environmental Protection Agency, according to the General Accounting Office.

* In a study published last September, the National Cancer Institute reported that dogs were twice as likely to get cancer if their owners used a common lawn herbicide four or more times a year.

* A 1987 study by scientists at the University of Southern California found that children whose parents regularly used home and garden pesticides were 6.5 times as likely to develop leukemia.

In retrospect, I'm glad I let those leaf miners have the spinach. If I had known what I was doing, though, I might not have gotten leaf miners to begin with.

A growing number of home gardeners, professional landscapers, city park departments and even the National Park Service are adopting a least-toxic approach to pest control, and they are finding that they can save money and still have healthy plants.

And so can we. If you use pesticides in your garden, consider phasing them out. You just don't need them.

This column can't convey everything you need to know to switch to a least-toxic pest control strategy, but it can give you an overview and get you started thinking -- and gardening -- along the right lines.

In general, the trick to keeping down pests and diseases is to promote a healthy garden. That means:

* putting the right plant in the right place. Shade-loving plants should be planted in the shade. Plants that like their feet dry should be planted where there is good drainage, and so on.

* choosing species or cultivars that are hardy and pest-resistant in your climate.

* planting a variety of plants in order to attract a variety of insects.

* planting vegetables at the right time. For example, only a fool would plant spinach in June in Washington, D.C. The way to get a spinach crop there is to plant in early spring, before the leaf miners are on the prowl, and again in early fall, when they've retired for the year.

Once you have the right combinations of plants in the right places, monitor the pests in your garden. There are a variety of tricks in the non-toxic arsenal that you can resort to as needed. For example, physical barriers, such as netting and copper collars, work for some kinds of pests. Others, such as Japanese beetles, can be trapped in gadgets you can buy at a garden store. You can also buy predatory organisms, such as ladybugs and nematodes, to prey on your pests.

There are also a number of products that are technically insecticides but aren't hideously toxic and break down very quickly. Insecticidal soaps and botanicals -- insecticides made from natural plant products -- fall into this category. Botanicals, however, are extremely toxic to fish. Never use them anywhere near the water. The most important weapons in your least-toxic arsenal, however, are the home reference books you can quickly turn to if a plague of loathsome, garden-eating insects descends on you overnight.

Sharon Taylor, of the California-based Environmental Health Coalition, recommends these two: "Tiny Game Hunting," by Klein and Wenner, and "Common Sense Pest Control," by Olkowski, Daar and Olkowski. Both books address home as well as garden pests, and both are available in bookstores. Buy one now, before those bugs send you screaming for pesticides.

(Feeling environmentally incorrect? Write a letter to Ms. Household Environmentalist -- on recycled, unbleached paper, of course, using soy-based ink -- and send it to P.O. Box 121, 1463 E. Republican St., Seattle, Wash. 98112.)

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