A Three Sisters Garden is the historical practice of planting corn, pole beans and squash together.
These three plants grown together complement each other and are a great use of space. Said to be a perfectly balanced harvest that makes the most of the growing space.
The corn plants are a living support system for the pole beans. The squash plants grow along the ground sheltering the roots of the beans and corn aiding in retaining moisture. The beans grow up the stalk, strengthening the plant and puts nitrogen back into the soil.
Planning Ahead for you Three Sisters Garden
Hardening Off Indoor Started Plants
We suggest both options for inground started seeds as well as discuss starting seeds indoors for this companion planting set up.
Any plants started indoors must be hardened off before being planted outdoors. This period takes around 2 weeks for the plants to acclimate to the outdoor weather conditions.
Once the days are warm, set the seedlings outside in a sunny, wind protected location. Start with having them outside a few hours a day. Over two weeks, extend the time they are left outside by an hour or 2 every day. By the end of the second week, they can safely be transplanted into the garden provided the weather is warm and all chances of frost have passed.
Picking A Planting Design – A Three Sisters Garden
There are a few design options when planning your garden design. Depending on where you decide to grow the Three Sisters will determine the design. Planting in blocks makes it easy to maintain and harvest throughout the season.
The idea is to plant the corn seeds or seedlings first. You can plant the corn in staggered rows or plant 5 -7 plants in the center of a 3 foot x 3 foot mound having numerous mounds throughout the garden. Once the corn is 4 – 5 inches tall you can plant the beans. They should be placed an inch away from the base of the corn plants. Plant 2 -3 bean plants per stalk of corn. When the beans start to grow vines you can help them by leaning them towards the corn plants and if long enough wrap the bean vines around the corn. The climbing nature of pole beans will continue to grow up the stalk of corn.
The squash can then be planted along the base of the staggered rows or around the mounds. The vines will eventually spread as they grow to protect the root area of corn and bean plants.
We have included diagrams of the various planting designs below. Feel free to use the methods below as a starting guide to designing the best setup for your particular garden location.
Choose a garden location that receives 6 – 8 hours of direct sunlight a day.
The Three Sisters in a Three Sisters Garden
The type of corn grown in a Three Sisters Garden should be a variety that grows tall and strong. As the garden grows the vines of the pole beans use the corn stalks as a support system.
Corn does best in hot growing locations, place your Three Sisters Garden in the warmest location in the garden. Select a type of corn that will finish in your growing zone and consider starting your seeds indoors a few weeks before the final frost in your area. Corn is the first sister of a Three Sisters Garden that gets planted, and the 2 other sisters are planted accordingly.
Work the ground well at the selected growing location. It is important to add amendments like compost, peat moss and sand if your growing location has heavy soil. Peat moss lightens up the soil which encourages strong root growth. Sand aides in the drainage of the soil which is important, especially during wetter seasons.
Corn plants require pollination for the kernels to form in the cob. This happens when the wind blows and the pollen falls from the tassels at the top of the plants downwards onto the silk below. Because of this, it is a good idea to plant corn in blocks rather than rows.
Starting Corn Indoors
In growing zones that are hot with long growing seasons, corn can be directly seeded in the ground. In cooler locations it can be beneficial to start the corn indoors a bit earlier in the season. This gives you a head start on the garden which in cooler growing zones assures for the successful harvest.
Start the corn in trays using a seed starting mix or potting soil. These are available year-round at hardware stores with garden centers. Plant one seed per cell and water well. Cover the tray and place it somewhere warm and sunny as heat quickens germination. The corn should start to sprout between 7 – 10 days. Once the corn sprouts, remove the lid and place the tray in a sunny window or under fluorescent lights if you have them available. Be sure to water regularly, not allowing the seedlings to dry out.
Harden off the corn for a period of two weeks before planting it in the garden. Plants can be moved outdoors permanently once all chances of frost have passed.
Corn is the base feature of the Three Sisters Garden and should be planted first.
Direct Seeding Corn in the garden
Once the planting site has been worked well and all chances of frost have passed you can plant the corn seed in the garden.
As the cobs mature the silk turns from white to brown, the ears will fill out and become quite round. Corn is ripe anywhere from 15 – 23 days after silking. To test corn, peel back part of the husk revealing the kernels. Pierce a kernel, if the liquid is white or milky the corn is ready to be harvested. Pull the ear downwards and twist to remove it from the stalk.
You will be looking for a pole type bean when choosing a bean variety for your Three Sisters Garden. They come in a variety of colours and all will work well in this garden. You can mix things up by using a few different varieties of pole beans. Green and yellow pole beans are readily available and are very common. Or you can go with Scarlet Runner beans or some beautiful purple hued beans that grow on vines.
The beans are placed near the base of the corn. If you plan on direct seeding the beans, plant the corn first as their position in the garden dictates where we will plant the pole beans.
The beans can be both directly seeded in the ground or started indoors. Most growing zones in Canada allow for successful harvests from inground started seeds. You can start beans indoors in planting trays. Place one bean seed per cell and water well. Cover the tray and place it is a warm location. Beans can begin sprouting in as early as 4 days. Once the beans have sprouted remove the cover and place the tray in a sunny location or under grow lights if you have them available. Hardened off the beans before being planted in the garden.
You can begin harvesting the beans when they are 3 inches long. You can pull the beans off the vines by pulling down on the bean. If it gives too much resistance, hold the vine with the opposite hand to avoid damaging the growing vine. The plants will continue flowering giving you many weeks of harvestable beans.
When selecting a squash variety for the Three Sisters Garden choose one that grows on vines. Butternut, spaghetti squash, pumpkins or any type of winter squash are all great options in a Three Sisters Garden. Grow one or a combination of your favourites.
The purpose of the squash in this garden setting is to create shade for the pole beans and corn. The vines of the squash plants grow along the ground between the corn plants. This aids in moisture retention and acts as a living mulch to help reduce weeds.
Starting Squash Indoors
Squash can be started both directly in the garden or indoors a few weeks before the final frost of the season.
Plant the squash seeds in plantings trays using seed starter mix or potting soil. Place one seed per cell and water well. Cover the tray and place it somewhere warm. The seeds should begin germinating in 7 – 10 days. Once the seeds have sprouted remove the cover from the tray and place it in a sunny location or under fluorescent grow lights. Like the corn and beans, the plants need to be hardened off for 2 weeks before being planted in the garden.
The type of squash you are growing will determine when it is ready to be harvested. Some require staying on the vines to mature while others can be harvested and moved to an indoor location to finish ripening.
The easiest way to harvest squash is to cut the stem using a knife giving a good 2 inch handle on the squash.
For a deep dive into growing squash, we have a How to Grow featuring Butternut Squash.
Planting Methods in a Three Sisters Garden
The traditional planting method of a Three Sisters Garden. You will notice the addition of sunflowers at the back of the garden. These were often planted on the edge of a Three Sisters Garden to attract pollinators and at times would be a replacement for the corn. Often used in areas where there is a lot of rain.
Another traditional planting method in a Three Sisters Garden, the Hidatas method, is good for all gardening areas. Plants staggered through the garden.
This design is planted in a large square, often split into individual square plantings. The gardening method is used to preserve water and works well in dry areas.
Go with one of the designs above or create one that fits your garden location. Have fun and mix the varieties of beans and squash for a bountiful varied harvest.