By simply being nearby, one vegetable crop will also aid the growth of another vegetable crop. Lettuce and spinach, for example, thrive in the shadow of a taller vine. Companion planting is the practice of growing two or more crops in close proximity for mutual benefit.
Crop, beans, and squash are a classic trio of garden companions. The Three Sisters is a Native American name for this intertwined trio of plants. Grow corn and pole beans on a mound or small hill; then, at the base of the mound, plant squash or pumpkin vines.
For the beans to ascend, the corn will serve like a living pole or stake. The beans would aid corn growth by drawing nitrogen from the air and “fixing” or adding it to the soil. Corn and beans would be protected from animal crop invaders by prickly squash vines emerging at the base of the mound. In a small garden, planting The Three Sisters is an outstanding use of land.
Choosing the Right Three Sisters Varieties:
Here are criteria to consider when selecting crop varieties for a three sisters garden:
- Squash:
The only stipulation is that you use a winter squash variety that grows on vines that span the ground. These ripen in the fall, but they're called winter squash because of their hard outer rind, which helps them to last all winter. Summer squash varieties would not function because they emerge in single clumps instead of spreading as a groundcover.
- Beans:
Beans in a three-sisters garden are traditionally dried and prepared for later use, but green beans for fresh eating are also available. Modern "bush" beans are not capable of scaling cornstalks, so they must be "pole" beans (vine-type).
- Corn:
Grain corn was traditionally used, but sweet corn may also be used in three sisters planting. Because some modern corn varieties are short, the bean vines can easily overwhelm the stalks, choose a variety that matures to at least six feet in height, the taller the better.
Planting a Three-Sisters Garden:
There is no one-size-fits-all method for planting three sisters. To refine a method that fits with your environment and with the varieties you want to use, you'll definitely need to do some trial and error over many seasons.
- Make a 5 foot-diameter circular mound of soil and rake the top into a smooth planting field with tapered edges (the finished bed should be at least 6 inches tall). As required, incorporate compost and soil amendments into the soil.
- So that the corn has a head start, plant it first. On top of the bed, sow the seed eight inches apart in a 3-foot diameter circle.
- Place the bean and squash seeds once the cornstalks are 6 to 8 inches tall. The bean seeds are planted within the corn circle, one seed about 3 inches from each cornstalk. The squash seeds go near the edge of the bed, beyond the circle of corn; they should be about 12 inches from the nearest cornstalks, but spaced thinly, with about 24 inches between them.
- Guide the bean vines toward the closest cornstalk as they grow; you can bind them to the stalk with twine so they clamber upwards rather than along the bottom.
- Build as many circular mounds as you can, but leave plenty of room between them since the squash can easily expand beyond its bed to cover an area of around 10 feet in diameter.
- Water and weed the beds as required.
- The beans and corn would be the first to mature. Harvest the squash vines as they ripen, taking care not to step on them.
