|A well-managed garden has little need for chemicals.|
Many gardeners are quick to act when their garden is threatened and in the process of dealing with a pest they unknowingly create more problems. In an effort to kill an insect that is chewing leaves they may inadvertently kill ladybugs or honey bees that are beneficial to plants. By trying to poison gophers or mice they may harm pets or children. Eradicating weeds with herbicides may hinder the growth of the very plants they're trying to protect.
Integrated Pest Management (or IPM) is a common sense approach to dealing with pests through economical and appropriate responses. IPM is safe, effective, and scientific. It's a way of looking at your gardening decisions by thinking beyond the immediate threat and considering how your actions will affect your entire garden.
The U.S. Environmental Protection Agency (www.EPA.gov) identifies a four-step IPM process when dealing with pests.
The first step is to Set Action Thresholds. This means you should determine the point at which the pest becomes a problem and you need to act. Not every pest requires immediate action. Spotting a single Tobacco Hornworm on your tomato plant, accompanied by a few chewed leaves, is cause for some concern, but not enough to hire an exterminator to spray your entire garden with pesticides. When plants are defoliated you've waited too long. You have to determine when it's appropriate to deal with a pest.
The second step is to Monitor and Identify Pests. Not every insect is a bad one. And even the bad ones may have natural enemies looking for lunch. A few Tobacco Hornworms can be knocked off by you, your chickens, wild birds, or certain wasps. The reason to monitor and identify pests is for you to slow down and think about appropriate control before jumping too quickly to a decision of using pesticides or herbicides. There are many insects that may seem threatening at first, but after identification turn out to be beneficial bugs.
An important aspect of IPM is Prevention. This is the first-line of defense against pests. This requires some education on your part so you understand potential pests and how they can be deterred. If Tobacco Hornworms are a problem for your tomatoes, learning about wasp parasitoids is important. They naturally kill the Hornworm larvae and you constructing wasp shelters and nesting boxes may be worth the effort; the adult moths can be trapped in light traps. For other pests, rotating crops, mulching, fencing, choosing appropriate plant varieties, and encouraging beneficial predators are all possible actions in your garden. Chemicals are rarely a preventative measure.
Control is the final step of IPM. If prevention isn't working or isn't available, and if the problem has exceeded your Action Threshold, it's time to deal with the pest directly. If your hornworms are multiplying and causing excessive damage it's time to attack the culprit, but you should take proper control action. Try the least risky option first; broadcast spraying of pesticides is a last resort. You and your army of kids can march into your tomato plants to pluck off the caterpillars and scrape off the eggs. Try a bacterial control like Bacillus thuringiensis before insecticides; it won't harm most beneficial insects. If you opt for a chemical insecticide, use it only on the plants that are affected, not your entire garden.
The idea behind Integrated Pest Management is is continually monitor your garden through all four steps and act appropriately. Specific pests require specific prevention and control. There is no single solution to deal with all pests, all of the time. You want to minimize pest damage while minimizing environmental damage.
|Moths and butterflies are nice to look at but their caterpillars may be harmful.|
There are many control actions for different pests. Mechanical control is you taking physical action: plucking off that hornworm; pulling a weed; pruning off a diseased branch. Cultural control is the way you prevent pests: putting up a fence to keep rabbits out; pruning branches to increase airflow and decrease powdery mildew; planting disease-resistant varieties. Biological control is using natural predators: encouraging ladybugs to eat aphids; letting your chickens forage for grubs and larvae; allowing birds in your garden to eat caterpillars. Chemical control is selecting appropriate chemicals for pests: spraying glyphosate (usually Roundup) on perennial weeds at the proper time of year; applying a fungicide when cultural practice was insufficient; not applying pesticides by the calendar, but only when needed.
|Proper pruning lets in air and light and reduces fungal disease.|
The concept of Integrated Pest management may sound daunting, but it is simple in practice. Educate yourself about how different insects, plants, and animals react to each other in regard to your garden. Try to avoid reaching for a chemical spray and think about natural or cultural alternatives to pest control. This isn't organic gardening, but an approach to using appropriate measures for specific problems.
Commercial growers are learning that IPM is a cost-effective way to manage pests. You can find that the same cost-effective principles will work in your garden. They do in mine.