By Alton Sparks
University of Georgia

Controlling insects in your vegetable garden can be a challenge. From strictly nonchemical to "washday" applications of insecticides, the approaches to insect control are as varied as the people who garden.

Volume XXXI Number 1 Page 8

Many homeowners accept some insect damage, while others will tolerate none. The level of damage you deem acceptable largely determines the level of control required and can limit your options.

You have five basic options for controlling insects. Besides sanitation, there are cultural, mechanical (or physical), biological and chemical control.

Sanitation

With the loss of Dursban and Diazinon, home gardeners have no legal insecticides to control soil pests like white grubs and wireworms. Good sanitation is the first approach for controlling these pests and will help with others, too.

Remove all vegetation, including weeds, from your garden site when it's not in use. This makes the garden less hospitable for these insects. If these pests move into the garden after the plants are well established, damage is much less severe.

Cultural

These controls include selecting plants that resist or tolerate certain insects. And planting transplants, rather than seeds, avoids several pests that can attack germinating seeds and young seedlings.

Early transplanting and finishing the crop earlier in the year avoids pest buildup in late spring and summer. If you direct-seed, it may be better to delay planting so that seeds germinate and grow fast, shortening the time they're susceptible to seedling pests.

Mechanical

These are often the simplest and most overlooked controls. Physical barriers can prevent pests from reaching the crop until it's large enough to resist significant damage.

In a small garden, or if pest populations are low, just pick pests off plants and squash them. It's a simple, excellent approach for many home gardens.

Biological

Beneficial insects can provide efficient control. They feed on the insects that cause plant damage. But manipulating the beneficial insects can be tough. Both pests and beneficials readily move.

The most common and best approach to biological control is simply managing pests in a way that protects naturally occurring beneficial insects. If you see pests in the garden, check to see if anything is attacking them. Sometimes, all that's needed is a little time for nature to bring a pest population under control.

Chemical

Insecticidal control is still one of the quickest, easiest ways to control insects. But use it only when necessary.

Sticking to a strict spray schedule is a waste of money in most cases. It may actually create pest problems by killing beneficials. And it's generally not good for the environment.

Read and follow the label of each pesticide you use. Pay close attention to the crops a pesticide can and can't be used on and the amount of time required between the last application and harvest.

How all of these approaches can best be integrated into your final insect management program depends on your needs for pest control, crop quality and overall safety.

Gardeners willing to tolerate some insect damage can generally grow their plants with minimal use of insecticides. Those who require pest-free plants are often limited to a heavy reliance on pesticides.

(Alton Sparks is a Cooperative Extension entomologist with the University of Georgia College of Agricultural and Environmental Sciences.)