The Three Sisters—or Is it Four?

(An excerpt from Gaia's Garden)

Let's begin our exploration of guilds (communities of plants for the garden) with a very simple example that illustrates some essential principles. Then we can proceed to more complex guilds—ones that go beyond vegetables.

Familiar to many gardeners is the Native American triad of corn, beans, and squash, a combination often called the Three Sisters. The trio qualifies as a guild because each of these plants supports and benefits the others. The cornstalks form a trellis for the bean vines to climb. The beans, in turn, draw nitrogen from the air, and via symbiotic bacteria convert the nitrogen to plant-available form. These nitrogen-fixing bacteria, scientists have recently learned, are fed by special sugars that ooze from the corn roots. The rambling squash, with its broad leaves, forms a living parasol that densely covers the ground, inhibiting weeds and keeping the soil cool and moist. Together the Three Sisters produce more food, with less water and fertilizer, than a similar area planted to any one of these three crops in isolation. Jane Mt. Pleasant, an agronomist at Cornell University who has blended her Iroquois heritage with her research, has shown that yields of this guild, measured in calories, are about 20 percent higher than corn grown alone in an equal-sized plot.

Look at how many interconnections this guild bears. Beans furnish nitrogenous fertility for themselves, corn, and squash; squash shades soil for the benefit of all three; corn feeds the bean-hugging bacterial nodules and creates a trellis for the beans. Three plants, weaving at least eight connections. The Three Sisters guild is a perfect place to begin creating a richly connected garden.

In the Southwest, a fourth "sister" is found in this guild: Rocky Mountain bee plant (Cleome serrulata). Often growing near former Anasazi settlements—it's virtually an indicator plant for ancient ruins—this 2- to 5-foot tall, pink-flowered cleome is a powerful attractant for beneficial insects that pollinate beans and squash. The young leaves, flowers, and seed pods of bee plant are edible, and native people boiled and ate them, or made a paste from the plant for later use. Bee plant also accumulates iron, and thus is the source of a deep-hued paint used to create the characteristic black designs on Anasazi pottery. Songs and blessings of New Mexico's Tewa people mention corn, beans, squash, and bee plant, indicating that this multi-functional flower is an integral member of a sacred plant pantheon.

I was pleased to learn of this fourth sister, as it connects the web of this guild's beneficial interactions with the

Just out! The revised, expanded, all-color Second Edition!
Gaia's Garden: A Guide to
Home-Scale Permaculture

by Toby Hemenway

Chelsea Green, 2009.

“The world didn’t come with an operating manual, so it’s a good thing that some wise people have from time to time written them. Gaia’s Garden is one of the more important, a book that will be absolutely necessary in the world ahead.”

—Bill McKibben, author of Deep Economy and Hope, Human and Wild