Although the term “biodiversity” wasn’t originally used to describe long-standing cropping methodology in the “New World,” the practice called “Three Sisters” clearly earns that title. The Native American culture of “Three Sisters” greeted the earliest arriving European settlers.
Here’s what these Old World visitors were welcomed with: In a technique known as companion planting, corn (or maize, Zea mays), beans (Phaseolus genus) and squash (Cucurbita genus) were planted close together. The maize and climbing beans were often planted together in mounds formed by hilling soil around the base of the plants each year; then squash was planted between the mounds. In the Northeast, this practice increased soil temperature in the mound and improved drainage, both of which benefited maize planted in spring.
Each mound was about 12 inches high and 20 inches wide. Several maize seeds were planted close together in the center of each mound; in parts of the Atlantic Northeast, rotten fish or eels were buried in the mound with the maize seeds, providing additional fertilizer benefit where the soil was poor. In Iroquois farming, the fields were not tilled, enhancing soil fertility and the sustainability of the cropping system by limiting soil erosion and oxidation of soil organic matter.
The three crops benefited each other by being grown together. The cornstalk served as a trellis for the beans to climb, the beans fixed nitrogen in the soil and their twining vines stabilized the corn in high winds. The wide leaves of the squash plant shaded the ground, keeping the soil moist and helping to prevent the establishment of weeds. The prickly hairs of some squash varieties also deterred pests, such as deer and raccoons.
European records from the 17th century described highly productive indigenous agriculture based on cultivation of the Three Sisters throughout what are now the Eastern U.S. and Canada. Geographer Carl O. Sauer described the Three Sisters as “a symbiotic plant complex of North and Central America without an equal elsewhere.” Agronomists and horticulturalists generally agree that the Three Sisters mound system “enhances the soil physical and biochemical environment, minimizes soil erosion, improves soil tilth, manages plant population and spacing, provides for plant nutrients in appropriate quantities, and at the time needed, and controls weeds.”
Nutritionally, the combination of corn, beans and squash contain all nine essential amino acids as well as complex carbohydrates and essential fatty acids. The protein from corn is further enhanced by protein contributions from beans and pumpkin seeds (pumpkin flesh provides large amounts of vitamin A). With Three Sisters, farmers harvest about the same amount of energy as from corn monoculture, but get more protein yield from the inter-planted bean and pumpkin.
The underlying concept here is symbiosis (mentioned earlier). This concept largely explains the value of the Three Sisters over monoculture cropping, as the system yields large amounts of energy and at the same time increases protein yields. This polyculture system (growing three or more crops) yielded more food and supported more people per acre compared to monocultures of the individual crops or mixtures of monocultures.
Here’s anecdotal history supporting Three Sisters. It comes from descriptions of the First Thanksgiving. I’ll start by trying to answer the question “What was on the menu at that famous banquet, four centuries ago?” While no records exist of the exact bill of fare, the Pilgrim chronicler Edward Winslow noted in his journal that the colony’s governor, William Bradford, sent four men on a “fowling” mission, preparing for the three-day event. Wild turkey was plentiful in the region and a common food source for both English settlers and Native Americans. But it is just as likely that the fowling party returned with other birds such as ducks, geese and swans. Instead of bread-based stuffing, herbs, onions or nuts might have been added to the birds for extra flavor.
Whether or not turkey was served at the first Thanksgiving remains debatable, but one way or another, attendees got their fill of meat. Winslow wrote that the Wampanoag guests (members of the local Indian tribe) arrived with an offering of five deer. Culinary historians speculate that the deer was roasted on a spit over a smoldering fire and that the colonists might have used some of the venison to whip up a hearty stew.
The 1621 Thanksgiving celebration marked the Pilgrims’ first autumn harvest, so it’s likely that the colonists feasted on the bounty they had reaped with the help of their Native American neighbors. Local vegetables that likely appeared on the table include onions, beans, lettuce, spinach, cabbage, carrots and perhaps peas. Corn, which records show was plentiful at the first harvest, might also have been served, but not in the way most people enjoy it now. In those days, the corn would have been removed from the cob and turned into cornmeal, which was then boiled and pounded into a thick corn mush or porridge that was occasionally sweetened with molasses.
As part of the first Thanksgiving, I have mentioned two of the Three Sisters, corn and climbing beans. Now for the last sister, the Cucurbita genus, which includes squashes and pumpkins. Both the Pilgrims and the Wampanoag ate pumpkins and other squashes indigenous to New England – possibly even during the harvest festival – but the fledgling colony lacked the butter and wheat flour necessary for making pie crust. Moreover, settlers hadn’t yet constructed an oven for baking. According to some accounts, early English settlers in North America improvised by hollowing out pumpkins, filling the shells with milk, honey and spices to make a custard, then roasting the gourds whole in hot ashes.
Over the centuries, American agriculture has drifted away from the Three Sisters toward monoculture – and the accompanying unhealthy soils. Degraded soil health is believed to have intensified the ongoing drought destruction in the Mississippi Basin.