Beans, sweet corn and squash - these are the three sisters. Corn provides support for beans, beans bring nitrogen to the soil, and sprawling squash shade out weeds. The association provides carbohydate and protein (beans with corn), plus veg. It's a traditional growing system from Mexico way. Runner beans are from Central America where apparently they grow wild, ramping up through the trees. In my patch I grew red and white flowered runners. I added some stout upward bean poles (not teepee'd or in rows) because in our temperate climate the corn won't be tall and strong enough til at least mid-summer. I also added Thithonia rotundifolia, an annual also of Mexican origin, for some mid-height colour (1.2m), and for bees and butterflies. I'll show you know how it works out!