I have created several square foot garden plots, and even started all of my plants from seeds! (thecountrychiccottage.net)
For one 4 x 4 foot garden box with 6 inch sides, you will need 8 cubic feet of soil mix. (wellnessmama.com)
I've gotten into the habit of growing my own produce via a square - foot garden at my dad's house and joining a community garden as well. (greenjuiceaday.com)