Three sisters - beans, squash and corn in clever intercropping

To practice companion planting with vegetables is a great way to save space, but most importantly, plants with different characteristics can benefit from each other - especially beans, squash, and corn. The Inca people in North America already cultivated these vegetables together, calling them the three sisters. Here we will tell you more about this cultivation technique.

There is a lot to gain from intercropping corn, squash, and beans. The squash covers the ground with its large leaves and prevents weeds from establishing, the beans in turn fix nitrogen in the soil, providing nourishment for the others, and the corn acts as a support for the beans as they climb upward.

This is how you cultivate the three sisters

Squash, corn, and beans grow quickly and can be successfully pre-cultivated in May in most places. They will be ready to plant outside once the risk of frost has passed. The sisters thrive best in nutrient-rich soil and in a sunny, warm location. It's a good idea to cover the plants with fleece for a couple of weeks after planting them out, allowing them to gradually acclimatize to outdoor conditions in a gentle way.

Corn

Corn should be planted in rows to be well pollinated by the wind. If you live in any of the milder hardiness zones, you can directly sow some seeds on small mounds (30 cm wide and 5 cm high), but if you live in colder areas, it is best to pre-cultivate small plants indoors. The plants should be pre-cultivated in deep pots and not sown too early, as corn does not like to stay in pots for too long. Choose a tall-growing variety that grows quickly, and do not plant other corn varieties nearby, as it may disrupt pollination. If the roots stick out at the base, you can cover them with soil, otherwise there is a risk that growth will stop. Tips! If you are not a fan of corn, you can replace it with sunflowers, which provide food for hungry birds in the fall.

Beans

Climbing beans or pole beans are sown in a circle around the corn on the mounds. Beans can be pre-cultivated indoors, but can also be directly sown at the same time as you plant the corn and squash - beans thrive outdoors only when the soil has warmed up properly. It is also possible to sow the beans a little later than the other sisters, so that the corn gets a head start and becomes a better support for the beans. If the beans grow too fast, you can give them temporary support poles until the corn has caught up with them. Harvest the beans regularly as soon as they are ready, so the plant sets new flowers that produce more pods.

Squash (Zuccini)

Plant squash between the small mounds of corn and beans, with a distance of about one meter. The Inca people probably mostly used winter squash for companion planting, but you can use any type of squash. Squash grows quickly, so there's no need to start cultivating it too early; in most places, it's enough to start in May or sow directly outdoors. Make sure the plants get plenty of nutrients and light so they become robust and healthy. When the squash has grown large, you can remove dead leaves and leaves at the bottom near the soil surface, making it more airy and providing more space for the fruits. Squash is a thirsty plant and needs regular watering; it also loves nutrients, and despite the beans providing nitrogen to the soil, the three sisters may need fertilizer a couple of times during the summer.

Tip! If you find yourself with a lot of squash (which can happen quickly), check out our 8 tips on how to use and store squash.