This year at the Derwood Demo Garden we acquired some new planting space, which I decided to use for a growing technique we just haven’t had the square footage for in many years: a Three Sisters garden. Growing corn, beans, and squash together in this symbiotic way is an innovation of several Native American peoples, particularly the Haudenosaunee or Iroquois. Each of the sisters has a role: the corn, grown in small groups in separate hills, creates a tall structure; the beans twine up the corn and stay high up for picking; the squash spreads out to suppress weeds and deter animals.
The process we used as a model is explained here and you can read more information here.
Here are some things we learned from growing the Three Sisters this year:
- We followed the instruction to wait until the corn is four inches high before planting the beans, and then to wait till the beans sprout to plant the squash (and watermelon, because four sisters are even better). With hindsight, I think I’d plant the squash at the same time as the beans, especially since our squash planting ended up happening just before a dry period which delayed germination. It’s doing fine now, but took long enough to get started that it didn’t perform its weed-suppression role while the corn was producing.
- Tradition (and common sense) advise using field corn, dry beans, and winter squash, so that you don’t need to go into your planting after the early weeding stages until the fall harvest. We decided to grow sweet corn (because we love those food bank donations) and harvest our pole beans green. Since our cucurbits were slow to get going, we had no problem harvesting the corn. What we didn’t anticipate was that the cornstalks weren’t strong enough for the bean vines – we had several corn collapses! So, either grow a corn variety with stronger stalks, or add a stake to each hill to tie up the corn.
- Sweet corn is one of the more problematic crops to grow when you only harvest once a week. I don’t think we hit the harvest date quite perfectly, but the ears were neither vastly undermature nor overmature.
We got a sizable corn harvest out of our six hills of ‘Incredible’ (forgot to weigh it separately, but it was part of our largest ever weekly donation of 216 pounds), are still picking beans (about five different types), and are watching the squash (butternut and other varieties) and watermelons grow. All in all it’s been a worthy project and we’ll probably do it again.
By Erica Smith, Montgomery County Master Gardener
What varieties of corn, beans, and squash did you use? I have a packet of Silver Queen seeds I want to try this with.
To be honest I can’t remember at this point about most of them – I mentioned ‘Incredible’ corn above and I see a label for Missouri Wonder beans, but those were probably just the seeds we had. Just about any type will work – just be careful not to let the beans overwhelm the corn as we experienced, maybe even adding some stakes if necessary. For the squash you want to avoid bush or compact types, obviously – the ramblier the better. We also grew some watermelons. Good luck to you!