I raised chiles and tomatoes in two square foot gardens (raised beds 4'x4') last summer. I did as instructed and marked off 16 square foot "plots" in each bed and planted one plant per square. They flourished and are so easy to keep weed free because you can walk all the way around them. You never compact the soil by walking on it. Don't think you could plant them much closer than that as they got really big and leafy but also produced loads of peppers. The tomatoes didn't fare as well...got some sort of blight that took all the leaves off mid-season and left these naked plants with the tomatoes hanging on them....weird! SandyO CH #1146 of the moderate persuasion, growing only moderate chile plants of course!