A perennial polyculture is an arrangement of three or more species of plants – that live more than one season, often many – growing together. They are selected for maximum cooperation for mutual benefit.
Perennial food plants are high in proteins, fats and carbohydrates, are not destroyed by harvest, yield for multiple years and require no tilling. They provide many ecosystem services, including sequestration of carbon, stabilization of slopes, regeneration of soils; resistance to extreme weather, and resilience.
Perennial crops are long lived and require little maintenance. Indeed, no one waters, prunes, mows, weeds or fertilizes a forest. Ecosystems self-organize to provide these and other functions necessary for the entire community to thrive.