This document provides an introduction and overview of companion planting. It discusses how companion planting works by creating diversity in the garden and using plant combinations that attract beneficial insects, repel pest insects, enrich the soil, or act as trap crops. The document then provides tips for getting started with companion planting and growing a companion garden. It concludes with a plant-by-plant guide that provides allies, enemies, and growing guidelines for various plants commonly used in companion planting, such as asparagus, basil, beans, and beets.