The Three Sisters
By Catherine Dougherty
In Native gardening, there are three sisters: corn beans and squash. They are not just plants, as if there is such a thing as "just a plant". When you grow a good strong tall corn, not like sweet corn or popcorn, she acts as though she is a post for beans to climb and be shaded from excess of sunlight.
The beans planted at her feet provide an even more valuable service in return, giving the corn the benefit of her nitrogen fixing colonies of fungus, symbiologically noded in her roots. They provide nitrogen fertilizer absorbed from the air not only just when the roots and vines return to the soil, but also all throughout the growing season when water leaches it into the soil.
Thirdly, the squash, who is shaded enough by the two other sisters, covers the rest of the hill with wide leaves, protecting the roots and the hill from excess sunlight and evaporating, becoming a living mulch that keeps the soil moist and cool. sun exposed soils release carbon more readily, making them decrease in water retention and fertility even greater than the effects of evaporation alone. Covered soils have fewer weed seeds germinate, and few out compete squash. Squash with her prickly spiny leaves and stems, deters the soft little hands of corn hungry raccoons!
What a marvelous plan!