https://en.wikipedia.org/wiki/Three_Sisters_(agriculture)

The Three Sisters […] are the three main agricultural crops of various indigenous people of Central and North America: squash, maize (“corn”), and climbing beans […]. […] In a technique known as companion planting, the maize and beans are often planted together in mounds […]; 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.