Archive for Sunday, April 29, 2001

It’s easy to be green

Alternative pesticides are kind to the environment

April 29, 2001


Having a "green thumb" has taken on new meaning. For a long time, the phrase was used to describe people who had a way with plants, who could grow wonderful gardens no matter the methods they used.

But that has changed in light of the Environmental Protection Agency's recent ban on Dursban and the phasing out of Diazinon the two most popular chemical pesticides in the United States.

Today, having a green thumb might well mean growing a garden without benefit of artificial chemicals for pest control and fertilization.

To market, to market

Many alternatives to chemical pesticides are making their way to the marketplace.

Gardens Alive!, a proponent for biological control of garden pests and natural gardening practices for 20 years, has an array of products that offer alternatives to chemical pest control. Intagra Inc./Necessary Organics has also been in the business of natural pest-control products for more than two decades.

These companies, and others like them, manufacture products with natural, active ingredients such as chrysanthemum flowers, eggs, boric acid, fossilized remains of aquatic plants, pepper and mustard extracts, and seed and plant oils.

For example, Pyola Insecticidal Spray from Garden Alive! combines pyrethrin a natural insecticide derived from chrysanthemum flowers with canola oil extracted from rapeseed.

This powerful spray reportedly kills insects in all life stages, from eggs to adults. It is effective against vegetable and fruit tree pests like cucumber beetles, whiteflies, leafhoppers, Japanese beetles and caterpillars.

Another product, Neem-Away Insect Spray, is made from the extract of the neem tree seed, which has been used for centuries for insecticidal purposes.

Neem-Away is said to be effective against pests including aphids, caterpillars, gypsy moth larvae, webworms, mealybugs, squash bugs and Japanese beetles. It works by suppressing the insect's desire to feed and disrupts its hormonal balance so it dies before it molts.

Intagra Inc./Necessary Organics has a product called Concern Citrus Home Pest Control whose active ingredient is orange peels. Concern Citrus can be used to kill ants, roaches and crickets. A study done by Granovsky and Associates found that Concern Citrus Home Pest Control had a higher kill and residual control rate for cockroaches than Dursban over a 27-day period.

Though less toxic than chemical pesticides, these alternative products are potent and may destroy beneficial insects as well as pests. They require precautions during use.

As always, follow label directions carefully. Wear gloves and protective clothing when applying any kind of insecticide.

Use the products after honeybees have returned to their hives. Avoid spraying on windy days, always wear a mask and remove contact lenses when applying dusts.

Biology 101

Many effective biological pest controls have become available during the past 20 years. A common biological control is Bacillus thuringiensis (Bt), a bacterium that kills many kinds of insect larvae by paralyzing the digestive system. Bt is sold as a dust or liquid under trade names including Dipel and Thuricide.

Some gardeners have found pest-control success with Diatomaceous Earth (DE), produced from the fossilized skeletons of marine creatures known as diatoms. Razor-sharp particles puncture the soft bodies of slugs, beetles, aphids and other pests, killing the insect through dehydration. (Beneficial insects, such as ladybug larvae, may also fall victim to DE.)

Insecticidal soaps, made from potassium salts of fatty acids, also induce dehydration. Because some plants may be sensitive to insecticidal soaps, it is advisable to test a small area first. Soaps should not be sprayed on hot, sunny days.

Some gardeners use specially made garden barriers, beer baths and other unique methods to keep pests from chewing on tender plants.

For the purists, natural pest control means handpicking pests off plants and destroying the critters. Others encourage snakes, bats, frogs and toads to take up residence in the garden and feast on the undesirable insects.

It's also true that gardeners are by nature pretty generous. Most gardeners find that a few bugs chewing on a plant is a small price to pay for a garden that is chemical-free.

Healthy gardens are definitely possible without the use of chemical pesticides. And we will all be better off for it.

Carol Boncella is education coordinator at Lawrence Memorial Hospital and garden writer for the Journal-World.

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