Sharing your vegetables, flowers, trees, shrubs, and lawn with insects is a balancing act. On the one hand, you want a safe, attractive landscape and bountiful, pesticide-free harvest. On the other hand, armies of marauding insects and other pests may seem intent on destroying your dreams. What’s an organic gardener to do?

The answer is integrated pest management, called IPM for short. Success with IPM depends on careful and regular observation of your plants, the weather, soil conditions, and other factors that influence plant and insect growth. You also have to get very familiar with each important pest. Here’s what you need to know:

• Pest identification: You have to know exactly which insect(s) you’re dealing with. Capture a few in a jar to get a good look at them. Use a magnifying lens for small pests. Ask your local extension office for a color guide to common pests and their symptoms for your particular crop or ornamental plants. Extension entomologists (people who study insects) can also identify pests for you.
• Understand the pest: Learn as much as possible about when the pest appears, on which plants, what factors contribute to its abundance, what kind of damage it does, at what life stage it is easiest to control, where it lives when it’s not on your plants, and what controls it naturally (beneficial insects or disease, for example).
• Population size: Knowing whether you have just a few aphids or a cast of thousands makes a difference in how you deal with them. After you spot a particular pest or symptoms of its damage, examine as many similar plants in your garden as you can to determine the extent of the population and its distribution. Traps can help you evaluate the population of some pests.

Deciding whether to control the pest or let it be

After you identify and profile a pest, you have a choice about how to control it — and whether to control it at all. Consider the following factors when making your decision:

• Crop value: Are you looking at a small planting of annual zinnias or your family’s strawberry patch? Obviously, a valuable fruit crop warrants more intervention than an easily replaced ornamental.
• Extent of the damage: Is the pest confined to a single plant, to the one end of one row, or to the entire crop? Is the damage mostly cosmetic, will you lose a significant percent of the harvest, or will the tree’s or shrub’s health be significantly reduced?
• Your tolerance threshold: Can your family live with blemished apples, using them for sauce and cider? Or do you plan to sell them for fresh eating at a roadside stand? Are your roses going to be entered in a contest, or will they simply grace your own house and garden?

You have many control methods from which to choose. Organic gardeners choose the least invasive and least toxic methods first and graduate to harsher steps as necessary.

Making the garden less inviting to pests

Your garden may be unintentionally rolling out the red carpet for insect pests. Bugs are opportunists that take advantage of weak or stressed plants. They also take up residence where the eating is easy. Keep pests at bay with the following prevention strategies:

• Give plants the advantage. Choose the right location for each plant, taking into account its particular needs for water, sunlight, and nutrients. When plants don’t get their needs met, they become stressed, and the longer the stressful situation continues, the greater the decline in plant health. Think of insects as opportunists waiting for a weakened plant host to hang out the welcome mat. Of course, even a healthy plant can fall prey to insects and diseases, but it will be better able to survive the attack than will a plant that’s already weakened.
  
  Damaged bark or leaves are ideal entryways for insects and diseases. You can’t lessen the ravages of weather, but you can protect plants from mechanical damage from lawn mowers, trimmers, and rotary tillers. Encircle trees, shrubs, and perennial beds with a wide band of mulch to keep equipment away from plants.  ....read more