Sisterhood of the Trellising Plants: Corn, Beans & Squash

If you planted your summer garden early enough, it should be bursting to life right about now. You'll have rows of towering tomato plants, leafy basil perfuming the yard, and long green tendrils of cucumber plants reaching to latch on to just about anything. You may also have the trio of corn, beans and squash - which your nifty gardening how-to guide instructed you to plant together - but did you ever wonder why they grow so well together?

small flower on the squash plant

This garden trifecta is known as the Three Sisters, and is an example of companion farming in which different crops mutually benefit from each other when planted closely together. Because corn grows tall, the beanstalk is able to coil itself around as if it were a natural bean pole. The squash’s job is to deter both weeds and pests while locking in moisture near the base of the plants; which it does with the help of broad leaves and spiky, rough tendrils. Bacteria gathered at the bean’s roots fix nitrogen to the soil, which corn needs to grow and thrive. As an added bonus, the three plants differ enough that any major weather or pest conflict is unlikely to conquer all three. For example, a long, dry spell that wilts squash and bean suits corn just fine. The same wet, muggy season that beans can thrive in often causes corn and squash to produce weakly. Although it’s not ideal to lose any crops, it’s better to have something than nothing.

Sound revolutionary? Not so! People indigenous to North America were practicing this agricultural technique thousands of years before the Wikipedia page was published. In fact, the Three Sisters, who were also referred to as the “sustainers of life”, were essential to the society; interwoven into the wellbeing - both spiritual and physical - of its people. Not only do they provide a sustainable, reliable source of food, but a nutritionally balanced one. Beans are rich in protein, and carbohydrates from corn provide quick and long-lasting energy. Squash supplements the pair with vitamins, minerals and other phytonutrient compounds that have antioxidant and anti-inflammatory properties, as well as plant-based fats from the seeds.

sauteed squash being tossed in a hot pan

Healthy, happy plants, like the harmonious Three Sisters, are not only at the peak of nutrient density, but also flavor! Have you ever heard “what grows together goes together?” Succotash is a timeless southern classic that combines sweet corn and beans with some sort of rich fat, like butter or pork drippings. Other veggies, like tomatoes, sweet peppers, okra, and of course, squash, are always invited to liven up the party. Although it’s an inexpensive dish that’s historically gained popularity during times of hardship (like the Great Depression or World War II) succotash is delicious enough to be craveable year-round. For the record: corn, beans and squash don’t need each other to make a tasty dish! Each one is versatile enough to compliment a variety of recipes and preparations, so there’s something for everyone at the dinner table to enjoy.


This sweet and versatile grain that was first cultivated and domesticated over 10,000 years ago in Mexico, where it’s more often referred to as maize. The corn plant is a type of grass, related to wheat, rice, barley and sorghum, among others, and it’s a staple food in many regions around the world. The kernels can be eaten on or off the cob, in soups, salads or on their own. Soaking the kernels in lye, a process called nixtamalization, yields hominy, which can be dried and ground into masa harina (used to make tortillas, tamales, sopes and pupusas!). Corn is especially valuable in modern times as animal feed, and because it can be refined for the production of cornstarch, corn syrup, corn oil, grain alcohol, beer and even biofuel. Our favorite way to enjoy corn in the summer is probably the simplest; right off the cob, grilled and slathered with butter, salt and pepper... though it's worth noting that corn is also a deliciously crucial part to a Low Country Boil.

Whitney Otawka's Low Country Boil with Smoked Paprika Butter


The legume family consists of beans, peas and even peanuts, all of which offer a wallop of plant-based protein and fiber as well as other essential nutrients like iron, calcium, and B vitamins. They’re also relatively inexpensive and easily stored. The variety of bean used for a Three Sisters garden is flexible, but they must be a pole bean, not a bush bean. Butter beans (and lima beans) are one of our favorites for the summer. The name "butter bean" comes from the creamy "buttery" texture of the beans as they cook down, and the name "lima bean" relates to the fact the fact that when North America was first introduced to the beans, they were delivered in boxes labelled "Lima, Peru", a South American region that had been dining on the bean for centuries. Their smooth flavor enriches soups, salads and sides with ease.

Tomato Butter Bean Salad


Zucchini, yellow, and pattypan are all considered “summer squashes”, and are members of the curcubit family along with cucumber and watermelon. Unlike most winter squashes, all parts of the summer squash are edible, including the seeds, skin and even squash blossoms, which are a delicacy when stuffed with soft cheese like ricotta and then pan-fried! The skin of most summer squash varieties is rich in carotenoids like lutein, which acts as an antioxidant and supports the health of your eyes. The mineral content of summer squash is impressive; it’s a good source of magnesium, copper  and potassium and, to a lesser extent, iron and calcium. A small but significant amount of omega-3 fatty acids can be found in the seeds. Summer squash is mild and soft enough to be sliced and eaten raw in salads or slaw, but a simple saute causes concentrates their sweet flavor.

The benefit of using summer squash varieties in your Three Sisters garden is that you can harvest the delicious fruits of your labor early, but winter squashes and pumpkins will do just fine! They’ll be ready to harvest in the fall and can be store well so that you can enjoy them through the winter months. Butternut, acorn and delicata squashes are all rich in carotenoids, as well as vitamin C, potassium and folate. Unlike summer squash, the thicker skins should usually be peeled away, and you’ll scoop out the seeds - but don’t toss them as they’re a yummy crunchy snack when roasted! The flesh yields and develop a rich sweet flavor when roasted or simmered away on the stove.

Summer Squash Tartine with Arugula, Almonds & Honey Drizzle

Wanna party with the Three Sisters? Try these recipes: