This document is a weekly news column on companion planting from Thomas Clark, a master gardener. It discusses the concepts of companion planting and allelopathy, where certain plants stimulate or inhibit the growth of nearby plants through biochemical interactions. Companion planting involves arranging plants together that have symbiotic relationships, such as the "three sisters" of corn, beans, and squash grown by Native Americans. It can help pest management by using trap crops or attracting beneficial insects. The column recommends researching compatible plant combinations and keeping records when experimenting to develop a garden layout that stimulates plant growth while reducing pests.