Growing the Three Sisters Garden. Who are the three sisters? For many Native American communities, three seeds: corn, beans, and squash represent the most important crops. They complement each other in the garden as well as nutritionally. How do the three work together? Corn provides the tall stalks for the beans to climb; beans provide nitrogen to fertilize the soil while stabilizing the tall corn during heavy winds; and large squash leaves shade out weeds and help retain soil moisture.