IPM is a decision-making process that helps you determine whether, when, and how to treat a pest problem.

A major part of an IPM program is determining the number of pests that can be tolerated without causing unacceptable damage or annoyance. Pests are treated only when they reach that level. Then, many different treatment methods are mixed and matched (integrated) to produce the best results.

Is real damage taking place?
The problem of cosmetic blemishes on fruit caused by certain plant diseases is very different from damage done by termites chewing on rafters.

How many pests are present and will that number cause serious damage?
Many shade trees can support huge numbers of aphids without much damage other than a few yellowing leaves that drop prematurely. On the other hand, one flea on a highly allergic dog will cause great suffering.

In the garden, ask yourself if any natural enemies of the pest are present.
There are many kinds of beneficial insects, spiders, and other organisms that feed on pests and thus provide free pest control. Learn to recognize common predators such as ladybugs, syrphid flies, and lacewings. If you see them in abundance, you may want to postpone any treatments to see if these natural enemies will solve problems for you.

How many pests can you tolerate?
People differ in the number of pests they are willing to tolerate, and this tolerance level varies depending on the factors discussed above. IPM encourages people to think about their tolerance levels and experiment with tolerating a greater number of pests, especially in situations where damage is not serious.

For some pests, treatments must be timed to coincide with a period in their lives when they are most vulnerable to the treatment. Many scale insects can only be successfully controlled during the 'crawler' stage when the tiny, immature insects come out from under the hard, protective covering of the mother scale.

At first, using IPM methods may seem more difficult than just spraying a pesticide whenever you spot a pest. But as you become more familiar with IPM, the process will become easier and you can feel confident that you are creating and improving the natural balance in your garden and making your home and garden a safer place for the people and pets in your household.

Physical controls are barriers such as copper strips to keep slugs and snails away from plants, caulk to plug pest entry holes in buildings, or sticky barriers that keep ants out of hummingbird feeders. Fabric row covers exclude insects and birds from rows of vegetables, and special weed control fabric suppresses weeds. Your own hands are a physical control when you use them to squash bugs or pick snails off a plant. The humble vacuum has proved very useful in pest management. You can use it to capture white flies and other pests outdoors and ants, spiders, fleas, and cockroaches inside.

Cultural controls include designing the garden to minimize pest problems and doing routine maintenance in ways that keep plants as healthy as possible. For example, concrete mow strips between the lawn and a fence allow the mower to edge the grass, eliminating the need to use herbicides under the fence. Mowing your lawn at the proper height and fertilizing at the right times contribute to a more vigorous lawn that can out-compete weeds and resist pests. Cultural controls also include choosing plants that resist pests and that will grow well in the kind of soil in your garden and the amount of sunlight available. (See the Physical and Cultural Controls section for more details.)

Biological controls are used mainly in the garden and enlist other living creatures to attack pests. You can probably find many biological controls, such as ladybugs, spiders, and ground beetles, thriving naturally in your garden, but you can also buy a wide variety of beneficial organisms from special insectaries. (See the Buying and Using Beneficial Organisms section for more details).

Least-toxic chemical controls are usually the last-resort option. If you use chemicals, consider their safety for humans, pets, and the environment. Always read the label! Look for environmentally friendly products that, when used properly, are less disruptive to beneficial organisms and are less likely to cause water pollution. These include products such as insecticidal soaps and oils, desiccating dusts (diatomaceous earth and silica aerogel), boric acid and borates, and some botanical pesticides that are derived from plants.