A practical guide to planting corn, beans and squash in a supportive ecosystem

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The “Three Sisters” is an agricultural system developed by Indigenous communities of North America and refined over centuries through observation, experimentation and cultural knowledge. Today, it is widely used in permaculture because it demonstrates how plants can cooperate to create a small, self-supporting ecosystem that improves soil fertility and increases resilience.

This method combines corn, beans, and squash on the same plot of land. Each plant contributes something essential: structure, nutrition, or protection. When grown together, they create higher yields, healthier soil, and more biodiversity than when grown alone. Studies—including recent trials in the permaculture community — show that Three Sisters plots often maintain soil nitrogen better and use water more efficiently than monocultures.

Why These Three Plants Work Together?

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Corn: grows tall and stiff, providing a living pole for the beans to climb. Without corn, beans would need artificial support structures.

Beans: climbing beans convert atmospheric nitrogen into a form the soil and neighbouring plants can use. This naturally fertilizes the corn and the squash, reducing the need for added compost.

Squash: with wide leaves and a spreading growth pattern, squash functions like a living mulch. It shades the soil, reduces evaporation, suppresses weeds, and creates a cooler, moister microclimate that supports all three plants.

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Research from Indigenous agriculture archives and modern permaculture trials (such as the 2019 Permaculture Association experiment) shows that this combination increases overall productivity per square meter and builds long-term soil health.