The Three Vegetable Sisters

This month it is time to plant three favorite summer vegetables—corn, squash, and beans. There are more, of course, but these three have a long association. Early Indian and Spanish farmers throughout southern and central America grew these staple crops, taking advantage of each species’ unique characteristics. They referred to them as the three sisters. Beans are twining vines that need a support, corn grows as a tall single stalk, and squash plants sprawl across the ground. As an added benefit, blue-green bacteria in symbiosis with the roots of beans pull nitrogen from the air and feed it to the plant. Some is also released into the soil to feed other roots, in this case corn and squash. All grow in the heat of the summer, so now is the perfect time to plant them.

It is pretty widely accepted now that the edible squashes were domesticated in Central America, possibly as early as 8,000 years ago. They traveled north into Mexico, where they sustained generations of people before the advent of European explorers. The corn, bean, and squash varieties that the Indians and early settlers grew were for winter storage. Native corn was ground into meal, beans were left to dry on the vine and then shelled, and hard squashes were also stored for cooking later. Eventually, more tender varieties of summer squash were selected and sweet corn and fresh green beans began to make their appearance, as well. It is interesting to note that one of the earliest of the summer squashes made its way to the old country and was given the name zucchino in Italy. What’s also interesting is that even though California had been colonized by the Mexicans for several centuries, it was an Italian, Francesco Franceschi, who introduced zucchini to the Santa Barbara region sometime in his short stay between 1894 and 1914.

It is still possible, and maybe advantageous, to plant these species together. Prepare the soil by digging deeply, amend with compost, and mound into flat-topped hills, three feet or more in diameter and six inches high. Space hills with about a foot between their edges. Plant corn seed on top of the mound, and once they emerge, thin to three plants spaced about a foot apart. For each corn plant, plant two or three pole bean seeds. As the corn grows, the beans will twine up them. Plant one or two squash seeds (or substitute with pumpkins seeds here) on the mound. Legendary wisdom was that each mound would also have a fish buried beneath it, but to deter raccoons, dogs, and any other critters that might find that a reason to dig up the garden, another source of less fragrant fertilizer may be advisable. Mulch well and water deeply, as corn roots are known to penetrate up to five feet into the soil.

Within a couple of months, fresh beans and squash will be ripe for the picking. These two crops will continue to produce over the long summer months if they are regularly harvested. Corn is pretty much a one-crop wonder, but it is oh, so, worth it. Or do like the originals did and plant varieties that store well and harvest late in the season to feast on through the colder months.