The organization Send A Cow based in the U.K. has helped African families develop a unique way of growing a large amount of vegetables in quite a small area- essentially a large bag! The Bag Garden uses one large bag with compost and soil placed around a center column of rocks and stones. The vegetables are then planted around the edges and can fit up to 50 different plants. When water is poured down the center column it is then distributed evenly throughout the bag and not wasted, especially important in extremely dry environments. Unfortunately the kits can only be sent to U.K. addresses, but I think it's an easy enough design that you could duplicate it in your own backyard or apartment.