When people in South America began to farm corn and beans and squash, they worked out a system for growing all three plants in the same field that was good for all of the plants and made them grow better than they would have on their own.
Women planted the corn first, in the center of a garden circle.
Two or three weeks later, women planted the beans, all around the little corn plants in a larger circle. As the beans grew, they could wind their stems around the strong corn plants, and be lifted off the ground so their beans wouldn’t rot. At the same time, the beans added nitrogen to the soil, which helped the corn to grow.
In and around the corn, women planted squash like summer squash, or pumpkins, and the low leaves of these squash plants spread out and covered the ground, keeping the water from evaporating, so that the corn could drink it, and keeping weeds from growing up and choking the corn and the beans.
And to make this Three Sisters arrangement even better, when you eat corn, beans, and squash together (which North American people called succotash), they give you all the different kinds of vitamins and proteins that you need to be healthy.
People told a lot of stories about how the Three Sisters got together. You can read one of those stories here.