GARDENING : Natural Ways to Keep Pests at Bay

When it comes to weed control, a healthy, well-aerated, dethatched and nutrient-rich turf will choke out all but the most stubborn invaders. The rest can often be managed by hand weeding and mowing.

Pest management is really a matter of numbers. A few pests won’t make that big a difference and may even signal a healthy lawn. When your lawn is naturally disease- and insect-resistant, and is kept healthy using the methods discussed above, the degree of damage is often acceptable.

The natural approach pays the biggest dividends in the area of insect and blight control. Natural insect control takes two primary forms. You can use natural substances that attack the body of the insect directly, or release disease-causing microorganisms (fungi, nematodes) that burrow into the target insect, killing it in the process.

Here’s a brief look at some of the products with a record of success. These products are offered by a variety of firms, the Ringer Corp. being the most prominent. Ringer also markets the Safer line.

A word of caution is in order, however. Insecticides of any kind should be used sparingly and only as a means of last resort. Some beneficial insects will be killed in the process, no matter what you use.

One of the most effective, broad-spectrum insecticides is extracted from the seeds of the African and Southeast Asian neem tree. The active ingredient, azadirachtin, is a growth regulator, which is to say that it causes death. The Ringer Corp. markets this extract under the BioNeem trademark.

It’s effective on a variety of common pests, including aphids, gypsy moths and webworms. Though BioNeem has very low toxicity, it does have a two- to seven-day residual.

Insecticidal soap is another proven insect killer. It’s made from fatty acid salts derived from animal fat and plant oils. When sprayed on soft-bodied insects, it kills them by breaking down their cell wall membranes. Insecticidal soap works well on sod webworms.

For effective control of hard-bodied insects, such as June bugs and Japanese beetles, pyrethrum, an extract from the chrysanthemum flower, works well.

To treat infestations of subsurface grubs, you might try mail-order nematodes, which kill grubs from within, or milky-spore disease (bacillus popillae), a fungus that attacks grubs and other soft-bodied subsurface pests.

Once established, milky-spore disease remains effective for years. For treatment of billbug larvae, diatomaceous earth works. Diatomaceous earth is a sediment taken from the sea floor and is made up of millions of dead, single-cell creatures that dehydrate soft-bodied insects on contact.