The Iroquois tradition of a Three Sister’s garden (corn, beans, squash) is pretty common knowledge, so why, growing up, didn’t I see more people planting a three sister’s garden? Because the Iroquois are from further north than I am. I grew up in Virginia in USDA planting zone 7; the Iroquois are based out of upstate New York, which varies from planting zones 3 (up the mountains) to 5 (near the Pennsylvania border. My last frosts of the spring were a month earlier and my first frosts of the fall a month later.
While beans can be a little frost tender, finding a south facing spot protected by a wall isn’t too hard, so we’d push the beans into the ground a good week or two early, nearly April 1st. Corn, on the other hand, will need the breezes to pollinate, so protecting it with a wall is counter-productive. It also won’t put up with these frost shenanigans at all, so we didn’t bother pushing our luck. Plus, really good corn weather arrives soon enough, why plant it before June? The result: the beans are two feet high before the corn gets out of the ground.
In New York, however, summer arrives more abruptly, and the growing season is more condensed. The window for planting beans is nearly on top of the ideal window for planting corn, in which case, a good three sister’s planting makes a lot of sense.
To make this work, prep a few flat topped mounds, each two feet across. More than one mound is preferable and the mounds being 4 feet apart on center is preferable. (That’s a mound, a two foot wide path between them, and another mound.) There are two reasons for this: 1) corn is wind pollinated by corn within a 4 to 6 foot radius. You can’t put a tiny stand of corn on each side of your yard and expect them to help each other. (2) The squash plants will act as weed barriers. This will be more effective if the mounds are closer together, though too close will run you out of walking space.
About week before your ‘official’ last frost date, plant a ring of 6 to 8 kernels of corn in the center of each mound. Wait till the corn is about a hand high (a hand held sideways, fingers parallel to the ground, palm perpendicular) and then plant a ring of pole beans outside the ring of corn. When you plant the beans, take a minute to viciously rip out the weakest looking corn stalks. This is really hard for some gardeners. Steel yourself. Do it.
If you are direct sowing the squash, do that as soon as the beans germinate. If you are transplanting squash, take the ‘waiting for the beans’ into account when you calculate when to start your seedlings and give the beans a week or two to get going. Plant the ring of squash (summer, winter, pumpkin… it’s all good) just inside the edge of the mound.
In a week, come back and look for weak bean plants. Rip those out. As the beans grow, train the vines around the corn stalks. When the bean vines get to the top of the corn, pinch them off. As the squash grows, train it to spiral around the mound, but never into the middle. The leaves will be plenty huge enough to do the work of shading out weeds without the vines getting in the way of you stepping in to harvest beans.
And that’s it. You’ve planted a three sister’s garden! Remember to say thanks when you harvest.
<i>(Illustration from the CCE Native American Wiki. There are a lot of very cool illustrations of various cultural traditions at this site.)</i>