Three Sisters (agriculture)

The Three Sisters are the three main agricultural crops of various Indigenous peoples of North America: squash, maize ("corn"), and climbing beans (typically tepary beans or common beans). In a technique known as companion planting, the maize and beans are often planted together in mounds formed by hilling soil around the base of the plants each year; squash is typically planted between the mounds. The cornstalk serves as a trellis for climbing beans, the beans fix nitrogen in their root nodules and stabilize the maize in high winds, and the wide leaves of the squash plant shade the ground, keeping the soil moist and helping prevent the establishment of weeds. Indigenous peoples throughout North America cultivated different varieties of the Three Sisters, adapted to varying local environments. The individual crops and their use in polyculture originated in Mesoamerica; where squash was domesticated first, followed by maize and then beans, over a period of 5,000–6,500 years. European records from the sixteenth century describe highly productive Indigenous agriculture based on cultivation of the Three Sisters throughout what are now the Eastern United States and Canada, where the crops were used for both food and trade. Geographer Carl O. Sauer described the Three Sisters as "a symbiotic plant complex of North and Central America without an equal elsewhere". Agricultural history in the Americas differed from the Old World in that the Americas lacked large-seeded, easily domesticated grains (such as wheat and barley) and large domesticated animals that could be used for agricultural labor. At the time of first contact between the Europeans and the Americans, Carlos Sempat Assadourian writes that Europeans practiced "extensive agriculture, based on the plough and draught animals" while the Indigenous peoples of the Americas practiced "intensive agriculture, based on human labour". In Indigenous American companion planting, maize (Zea mays), beans (Phaseolus and Vicia spp.), and squash (Cucurbita pepo) are planted close together.