Milpa is a technique to adopt in the vegetable garden, and for consumers of squash, beans and corn. Originally used in North and Central America, particularly Mexico, it is still used in Latin America.
The corn plants serve as tutors for the beans, which capture nitrogen from the air, which the corn needs for its growth. The squash foliage acts as a living mulch, covering the soil, thereby retaining humidity. Finally, the “thorns” of the stems prevent herbivores from coming into the planting area and snacking on the other two crops.