I tried square foot gardening back in the 80's and it was great fun. I liked the idea that you didn't compress the ground at all, and that the plots were such a manageable size for bug and weed control. I was all about hand weeding and insect control. I would still use the method if the deer would just stop eating everything in sight.
Quote: I'm 5'0, if you have access from 3 sides the 4 ft mark is good (you only need to reach in 24 inches). If I'm going along a fence, I do 3 feet deep, because I can't walk to the back side to pick. Than again I'm unusually short.
I don't use the official "Square Foot Gardening" mix of ingredents for the soil but I do use raised beds (this year I've gotten some Earth Mover tires, big suckers!!!) My mix is a combination of chicken poop, potting mix, compost and good ol' North Carolina red clay. The only problem with red clay is come August when we are in the hottest part of the summer, even the soil that has been tilled deeply will get rock hard if it isn't watered just as deeply once a week. Once the top crust hardens, any heavy rain is going to run right off and not be able to soak in. (Rambling)
I have never followed the "rules" of planting on that comes on the back of a packet of seeds. Has never made sense to me. As long as you have room enough for light and water to get in your plants will grown. Tomatoes grown up and down, as do peppers, corn, carrots, potatoes. So you can plant them closer together. Plants like squash and bush beans grow out. They are going to need more room to spread.
I'm going crazy because the weather has turned a bit warm but here in Carolina, I know I can't plant anything until late April. Phewy!
If you go to the gardners.com website there is a garden planning tool that lets you plan each square foot and it tells you how many of each plant to plant into a sq ft. I found it pretty helpful since I am trying a lot of things this year that I haven't grown in the past.