Every new gardener who cares enough to research gardening, companion planting, or any assortment of fun garden blogs has heard of the famed 3 Sisters Garden. The system uses corn as a trellis for beans, and squash to shade out weeds. There are several stories about the three sisters, and they captivate the audience with ease, and are able to be traced back to Mesoamerica. The Tewa people are known for adding a fourth sister that attracted pollinators to the patch to ensure productive crops.
Due to the rampant internet stories mentioning the Three Sisters Method, the details often are glossed over, and this results in failure. I've seen it plenty of times, a new gardener posts about the method, several people confirm the greatness, and another handful of naysayers chimes in with "total failure, do not recommend," and "crops were too dense and I couldn't get into the patch to harvest, so it all rotted," and that's simply a disservice built on ignorance.
First, you can't really do a real Three Sisters garden in a small space. Each of these crops requires quite a bit of real estate to shine. Plant a single corn stalk and your corn will look like a 6 year old's tooth gap grin. The recommended space for a single Three Sisters setup is a 25ft circle. For the exact specifications, you can reference this awesome guide.
Once you know your space requirements, it's time to pick out the crops. Just grab some corn, beans, and squash, right? Not quite! Sweet corn, bush beans, and standard summer squash have no place here, banish those into the regularly harvested isles of the main garden. Three Sisters is here for the long game. Choose a corn that is meant to dry in the field, such as dent, popping, or flint. My favorite varieties are Bloody Butcher and Painted Mountain, the later of which is pictured here:
Next, choose a pole or tepary bean. A great source is here. My favorite is a little greasy bean that we added into the Appalachian Seed Story Project a few years ago, pictured below.
Finally, pick your squash! You need a winter squash that needs all season to produce a hefty yield on vigorous sprawling vines. A traditional choice in our farm's region is Seminole Pumpkin, which we are trying this year. In previous years I grew Jarrahdale(below) and Thai Kang. I try to choose C. Moschata for thier vine borer resistance.
Once you've got everything picked out, refer back to that PDF above for a planting schedule, and dive in! As the season goes on, you may have to do some basic maintenance and pest control to do, but the system is otherwise fairly easy to manage. Be sure to record your process and share with us! Happy growing.