Most people who garden have heard of the Three Sisters grown by Native Americans long before Europeans arrived on the landscape. Corn, beans, and squash, usually pumpkins, are grown together. Each grows better with the other two than it would alone. The details are usually a little vague on when to plant what, however.
Corn is planted first. It is a heavy feeder and is often fertilized with fish meal when planted. As the corn germinates and begins to grow, the beans and squash are planted. The beans are planted next to the corn. This allows the beans to use the corn stalk for support. In return, the beans fix nitrogen in the soil and give the corn more nutrients with which to grow.
The squash, often pumpkins, grow in the space between the rows of corn. The corn and beans, but especially the corn, shade the squash from the worst of the sun while letting in enough sunlight to allow the squash to grow. In return, the squash crowds out the numerous weeds that would take food from the corn if the squash was not there.
If you want to plant the Three Sisters the way it was done in the past, you can make low mounds about three inches high and two feet in diameter. You plant five or six kernels of corn in the middle of the mound. When the corn comes up, you plant beans in a circle around the corn. Finally, after the beans come up, you plant squash in the side of the mound. You will have to thin the corn down to two or three of the strongest stalks. The beans will have to be guided onto the corn stalks.
You plant many mounds about three feet apart so that your corn can pollinate properly. This method is a lot of work, but seems to produce well. Good luck with it.
