*Lakota greeting*
Hello, my name is Tada Vargas and I'm an intern with the National Laboratory
for Genetic Resources Preservation. NLGRP is located here in Fort Collins, Colorado--ancestral
homelands to the Arapaho, Cheyenne, Ute, and Oceti Sakowin. Today we will be discussing
three sisters agriculture which involves corn, beans, and squash. Three sisters agriculture
is an Indigenous historical practice and a great example of companion planting.
Have you ever heard of three sisters gardening? This practice is a historic gardening or
agricultural planting scheme in which certain crops are planted in close proximity to one
another. By planting in this way, the different crops not only improve their own health and yield
but also that of their companions or sisters. These benefits are not
only expressed in the current growing season, but in the next season as well.
Where did three sisters planting originate?
Three sisters gardening is a historic and traditional Indigenous agricultural
practice that originated in Central Mexico and spread throughout the Americas by 1000 CE.
Although this unique gardening practice is typically synonymous with the Northeastern tribes,
many indigenous groups across North America have utilized some version of this type of
companion agriculture. This map shows some of the regions where three sisters were planted together.
The dark blue region is the Haudenosaunee or Iroquois people;
the light blue are the Anishinaabe or Chippewa and Ojibwe tribes; the small pink is the Mandan;
the brown is the Ho Chunk tribe; the yellow is the Pawnee;
the orange are the Hopi and Dine or Navajo people; the purple is the Tarahumara people; and the green
are the Cherokee, Chickasaw, Choctaw, Creek, and Seminole tribes.
Who are the three sisters? The short answer is corn, beans,
and winter squash or pumpkin; however, particular varieties of each sister have been shown to relate
best with one another in a symbiotic relationship. Different tribes have their
own specific planting methods as well as unique varieties that worked best in their conditions.
Corn, also known as maize, is always planted first. As the eldest sister corn stalks provide a
strong, tall foundation for her other two sisters. Her stocks help reduce competition for sunlight
by creating a supportive vertical space for beans to grow upward, thus freeing the ground level for
squash to thrive horizontally. Corn's support extends below the surface as well. Her thick and
fibrous root system provides a dense foundation, giving the other sisters stability. Corn roots
utilize nutrients in more shallow levels of the soil profile compared to her sisters.
About two weeks after the corn has been planted or when she has emerged 4-6 inches above the soil
surface, the beans are planted. The bean variety needs to be a vining or pole bean
rather than a low growing bush bean. As the bean plant grows, she will wind her vines up
her elder sister's stalks. This symbiotic relationship provides a safe space for the
beans to climb and the intertwining bean vines stabilize and support corn's stalks. Beans also
assist both the corn and squash through their taproot system. The root system of the bean not
only grows in a downward direction so as to not take surface water away from the other sisters,
but it also has a unique capability to capture the essential nutrient nitrogen from the air.
Rod-shaped bacteria called rhizobia establish their symbiotic association with the beans by
forming root nodules--small growths in which the bacteria reside. Rhizobia are able to convert
nitrogen gas into ammonia, a form that can be used by plants to make amino acids, proteins,
DNA, and other essential compounds. In return the legume provides carbohydrates to the bacteria
as an energy source. Though the nitrogen obtained in this way is readily available to the beans,
a majority of the converted nitrogen will not be available to the maize and squash until the next
growing season. The legume root system will need to break down in order to release the nitrogen.
Last but not least, the squash is planted. The seed of the younger sister is sown at least one
week after the beans have been planted or after they have begun to emerge through the soil. Squash
grows in a sprawling manner, therefore her prickly vines and large, prickly leaves naturally protects
her sisters by inhibiting pests from coming near them. Also, her large leaf size helps suppress
weeds and retain moisture by shading the soil. As the squash vines sprawl in all directions they
sprout roots at points far away from the other sisters, thus reducing competition with them.
When do we begin planting and where?
Since the three sisters do not tolerate frost well, they are known as warm season crops.
Maize is typically planted in mid to late May in the Northeast when the ground is no longer
cold and wet. Traditionally the Haudenosaunee begin planting when the dogwood leaves are the
size of a squirrel's ear. The three general planting techniques are the mounding method,
the field method, and the landscape or rotational method.
The mounding method is typically used in regions where rainfall is abundant. In this
technique the three sisters are all grown in the same mound, generally with three or four
seeds each of corn and beans, and two seeds of squash. If multiple mounds are planted,
they should be spaced about three to four feet apart.
In the field method the sisters are grown in a square plot. The corn is planted in
the center in rows, and then the beans surround the corn in an outer square.
The squash is planted along one or two sides of the square plot.
The landscape or rotational method is typically used where precipitation is least abundant.
These sisters are planted in their own plots adjacent to each other.
After each season the crops are rotated to the right.
Since corn requires a high level of soil nitrogen, it is important that corn follows beans.
Why are these three crops significant? The three sisters complement each other
in their own special ways: corn creates a vertical growing space and structural support,
beans replenish the soil with essential nutrients, and squash wards off pest and helps retain water.
Research has shown that planting the sisters together results in
a yield increase of up to 30 percent compared to planting them separately.
Three sisters gardening also preserves traditional agricultural knowledge, reduces the dependence on
pesticides and synthetic fertilizers, and provides a hands-on relationship with food.
The three sisters were essential for the survival of Indigenous peoples and early European settlers.
Together they provide essential nutrients for meals to last through long, harsh winter
months. Maize is not only a carbohydrate source, but its high fiber content aids in digestion.
Also, it provides a source of B vitamins and minerals like zinc, copper, and manganese.
Beans are high in amino acids, which are the building blocks of proteins.
They are high in soluble fiber and provide other important vitamins and minerals like folate,
iron, potassium, and magnesium. Squash and pumpkin provide an abundance of antioxidants.
One serving of butternut squash provides more than 100 percent of the daily vitamin A
requirement and nearly 40 percent of the daily vitamin C requirement.
Historically, the three sisters were most likely dried for food storage and later prepared in
a soup. Society has become more creative in their three sisters dishes including burritos,
casseroles, stews, and stir fries. There are many communities which do not have easy access to
healthy foods, therefore three sisters gardening is returning as a heavily relied on practice
which can improve community nutritional status and aid in communal food sovereignty efforts.