Native Americans often planted three main plants together in a technique known as the Three Sisters. The three plants were corn, beans, and squash. Corn provided a sturdy structure for the bean vines to climb up while also providing food for the inhabitants. Beans provided nitrogen-fixing properties which helped to replenish soil nutrients that had been lost due to heavy harvesting of corn and squash. Squash was grown on the ground, acting both as protection from weeds and pests and providing nutrition with its edible fruit. This system ensured that all three crops could be harvested at once when they ripened in late summer or fall, giving Native Americans an easy way to provide reliable sustenance throughout each year.