In three of my gardens I use a Native American technique known as the three sisters. It was a form of companion gardening and crop rotation where corn, squash, and beans are planted together. The beans add nitrogen to the soil while the corn and pumpkins use nitrogen. The idea is to use pole beans which will use the corn plant as a pole, the beans can also help anchor the corn down! The pumpkins grow and their leaves form a natural mulch that both shades out weeds and the ground from the hot sun thereby helping with soil retention.