Native American traditions consider intergrowing crops as beneficial for fruit production, pest control and, in many cases, for improving flavors of vegetables. Commonly called "companion planting," intergrowing was regularly used by the Iroquois Nation as a means to plant vegetables such as corn, beans and squash together.
Mix 2 to 4 four inches of composted materials into the garden soil using a shovel, then rake it smooth. Soil makes a big difference in the outcome of any garden and should be rich and loamy for best results.
Plan the garden by drawing out where each plant will be and at what time. Intergrowing is not only good for crops that can be harvested together but also an efficient way to use the garden space. For example, plant scallions next to carrots that are a couple of weeks away from harvesting so the scallions can take over the space left by the carrots.
Plant tomato seedlings approximately 2 1/2 feet from one other and interplant lettuce seeds between each tomato plant. This will allow the lettuce to grow and be harvested while the tomato plants help to shade them. By the time the tomato plants get large enough to crowd out the lettuce, it will be time to harvest the leaves.
Plant corn in 3X3-foot squares. Set seeds approximately 2 feet apart, and between each seed interplant bean seeds. Plant squash around the outside of the square. The growing corn will be strong enough for the beans to climb on by the time the beans need support. The squash will grow and intermingle with the corn, shading the roots of the corn and the beans, and help protect them from weed growth.
Interplant marigold or nasturtium with beans to help deter bean beetles. Marigold is also good to plant around squash to retard squash beetles and around tomatoes to keep the nematodes and hornworms at bay.
End each gardening season with a cover crop of alfalfa, soybeans or other legumes, which absorb nitrogen to store in the plants. When these crops are finished, chop and till them into the soil to add nutrients, preparing the garden for next season.