Several thousand years ago, corn, beans, and squash grew together in the wild in Mesoamerica, near what is now Oaxaca, Mexico. The Haudenosaunee (Iroquois) called this planting combination The Three Sisters.
They planted these three plants together because they supported one another, helped one another to thrive through the combination of their different strengths - much like three Indigenous sisters might live together.
The Three Sisters: Corn, Beans, and Squash
The spiritual significance of Three Sisters
These three plants were considered precious gifts from the Great Spirit, and the growing season was marked at planting and harvest by ceremonies and rituals to honour the three Sustainer spirits that watched over them. 
“For many tribes, each plant was assigned a specific spiritual role, and each part of the plant (the roots, stems, leaves and flowers, as well as the fruits) was imbued with deep meaning and a role in native healing practices.” 
The story of the Three Sisters became legend and the plants (and seeds) were considered sacred - they were grown together, eaten together, and celebrated together and knowledge of growing, cooking, and preserving them was passed down many generations through storytelling and ceremony.
Ernest Smith, "The Three Sisters and the Jo'ka:o' Turning the Squash to Ripen", watercolour, 1937, from the collections of the Rochester Museum & Science Center, Rochester, NY [image source]
A Sustainable Polyculture
The Three Sisters Garden is a perfect example of successful companion planting.
Corn being the eldest sister, at the centre, the corn offers beans needed support.
Beans are the giving sister, pulling nitrogen from the air into the soil, to benefit all three. As the beans grow up towards the sun, curling around the stalks and vines, they pull the sisters close together.
Squash, with its large leaves and sprawling vines, protect the three by shading and cooling the soil, keeping it moist and preventing weeds. The spiky leaves also deter predators.
Together, all three come together in a sustainable polyculture, building soil fertility and providing nutritious food.
When European settlers arrived in North America in early 1600s, the Iroquois had been growing these plants together for centuries. The European settlers, learning from the Iroquois, reproduced these growing methods and thus were able to feed themselves and survive in this new place.
The three crops together provided complete nutrition for the Iroquois, which is reflected in many traditional recipes, such as succotash. Corn provides carbohydrates, beans offer protein and amino acids, and squash provides vitamins and minerals.
Devastatingly, due to colonization and cultural genocide, the spiritual and cultural significance of ancient growing methods and the stories that surround them have been lost. Furthermore, in the last century, commercial agriculture, the prevalence of monoculture, genetic modification, and so on, have displaced polyculture, heirloom seeds, seed saving, etc and caused irreversible damage to Earth’s biodiversity.
Tips for growing the Three Sisters garden
Choose Heirloom Seeds
- Preserving these heirloom varieties is important to the preservation of indigenous culture and heritage as well as biodiversity.
- Different heirlooms were grown for specific purposes: cooking fresh, drying, seed oil, or long term storage
- Heirloom varieties are adapted to specific climates - heartier, more drought-resistant and adaptable for example - than modern-day industrial varieties
- Choosing the right corn variety is important, since it serves as the main structure of the planting
- The prevalence of GMO corn in particular has been very damaging. It has transformed this sustaining, culturally significant “mother” into an industrial commodity
Planting & Growing
Timing, seed spacing, soil fertility, the environment, and varieties are all important factors that come into play - paying attention to all of these factors are important, bringing us in a closer relationship with the earth and the plants.
- Choose a site in full sun
- Choose a corn variety that grows tall to support climbing pole beans. Oaxacan Green Dent, Black Aztek, Glass Gem, Bear Paw, Country Gentlemen, and Stowell’s Evergreen Sweet are all tall growing varieties.
- Amend the soil with plenty of manure, since corn is a heavy feeder - fish fertilizer and wood ash are good choices.
- Mound the soil about one foot high and four feet around to improve drainage and improve soil warmth
- Form a bit of a lip around the top of a mound. This lip will catch water and bring it straight down into the mound for thirsty roots. It will also prevent the sides of the mound from eroding because it doesn't let it all run down the sides.
- Planting should be done in a block and not a wide row, to ensure good pollination for the corn.
- For a bigger harvest, you can plant several of these mounds in staggered rows, spaced 4 feet apart in all directions
“Many Six Nations people honour the tradition of giving thanks to the Four Directions by orienting the corn seeds to the north, south, east and west.” 
- When your last frost date arrives, plant six corn seeds an inch deep and about ten inches apart in a circle of about 2 feet in diameter.
- When the corn is about 5 inches tall, plant four bean seeds, evenly spaced, around each stalk. About a week later, plant six squash seeds, evenly spaced, around the perimeter of the mound.
- Pull weeds at first and thin your plantings to provide enough space - as things grow, weeds will naturally be suppressed.
- You can also grow a sunflower in the middle of the corn planting for additional support (and beauty)
- Large, vigorous pumpkins are best planted in a separate space, as they could try to climb the corn and pull it down.
- At the end of the season, plant material (if not diseased) can be incorporated back into the soil to build up organic matter and improve soil structure.
For Seed Saving
- If you plan to save seed for next year, choose one variety of corn to grow at a time in a given area to prevent cross-pollination
- Read about the incredible history of Glass Gem corn in this article on Reconnecting With a Lost Heritage Through Rare Corn
Drying Beans & Corn
- Three Sisters gardening is a super low maintenance growing method for drying beans & corn
- Corn varieties best suited to drying: Oaxacan Green Dent, Black Aztek, Glass Gem
- Pole Bean varieties best suited to drying: Arikara Pole Bean, Hidatsa Pole Bean, Turkey Craw Pole Bean, Rattlesnake Pole Bean
Planting a Three Sisters Garden - a wonderful family activity
As one of three human sisters, I can say that this relationship is truly something special!
Have you ever grown a Three Sisters Garden? Do you have any tips or stories to share? Leave a comment below!
 Renee’s Garden “Celebrate the Three Sisters Corn Beans and Squash.”
 Indigenous garden traditions by Food historian William Woys Weaver in Mother Earth News.
 How to grow a three sisters garden in CBC Parents
Three Sisters: Exploring an Iroquois Garden from Cornell University