Let’s suppose that you have done all your homework and are familiar with the cultural requirements of your favorite plants. You have started a garden and your plants are growing great. Then one morning, after six weeks of hard work, you go to water your vegetables and all the leaves are gone. What if it was a commercial crop and now you have nothing to sell? The protection of plants from hungry pests is an age-old problem. Integrated pest management (IPM) is a decision-making process that is used to manage organisms that are harmful to the garden and is based on a fundamental knowledge of ecology. It applies an integrated approach of chemical, biological, mechanical, and cultural controls.

Plants interact with insects, animals, microbes, and other plants. Some insects, animals, and microbes are beneficial to the garden and others are destructive. Nonbiological factors such as climate and soil conditions affect the ecological balance of the garden. For example, an unusually cold, wet summer can promote fungal infections in plants. Alternatively, dry and dusty conditions may contribute to outbreaks of destructive planteating mites. This topic introduces some of the beneficial and harmful aspects of the interactions that may occur between plants and other organisms in either the rhizosphere (below ground) or the phyllosphere (above ground).