Companion Planting
Many plants have known beneficial or harmful interactions with other plants. These relationships can effect the flavor of neighboring plants, nitrogen levels in the soil (which each plants has preferences regarding), distribute nutrients throughout the soil by utilizing the root systems of different plants, deter pests from neighboring plants, host insects (plants can attract beneficial insects), provide protective shelter for neighboring plants, attract pests away from other plants, and because of the diversity inherent in companion planting, pests or disease cannot devour entire crops as they might with monocultural crops (planting only one kind of plant in large scale). When those relationships are understood and incorporated into a garden design it removes the need for pesticides, fertilizers, etc. It restores the natural balance and diversity of nature. Companion planting is one of the many integral aspects of intelligent design.