We planted this polyculture in a 10′x3′ ground raised bed. The sweet potato transplants and bush bean seeds were planted in a somewhat hexagonal spacing technique similar to what is describe in the Biointensive gardening method. Our garden beds are no-till. A top layer of compost was added to the bed a week before planting. Both sweet potato and bush bean seeds were planted at the same on May 8th. We started harvesting beans in early summer through fall, though as the sweet potato vines began to take over towards the end of the summer chocking out some of the bush beans.
Sweet Potato, Bush Bean, volunteer beneficial polyculture by mid summer
In late spring a layer of grassing clipping were added to the bed for mulch which lasted most of the growing season. All of the flowering plants in the polyculture came up as volunteers.
“What if we could blend the best qualities of interplanting and companion planting? Interplanting combines crops that minimize competition for sun and nutrients. Companion planting blends varieties that enhance each other. Natural plant communities, tuned by billions of years of evolution, do both. Why not emulate these plant communities in our gardens?” – Toby Hemenway, Gaia’s Garden
While not as complex as some polycultures, the sweet potato/bush bean/wildflowers (in my opinion) go beyond companion planting and interplanting. The sweet potato vines provide a living mulch that suppresses weeds and protects the soil from erosion and the sun (conserves moisture). The bush beans are legumes and are able to provide nitrogen to the soil. The wildflowers found in this bed are cleome (spider flower), garden balsam, and rose moss. All of these come up as volunteers all throughout our gardens. All three are excellent at attracting beneficial insects that will act as pollinators and predators to help balance pest problems. Rose moss also can be an excellent ground cover, though the sweet potato vines already do an excellent job in this bed. Garden balsam is also edible and has medicinal value.