"Build a Keyhole Garden"

An article from Backwoods Home Magazine for those living in arid, rocky environments, or otherwise where there is poor soil.

A keyhole garden is basically an aboveground circle garden with a notch in it resembling a keyhole (hence the name) and a composter directly in the center to continuously feed the entire garden. The purpose of the notch is so you can reach the composter easily without having to step into the garden. A keyhole garden should be no larger than about six feet in diameter. Any bigger than that, and the water and nutrients will have a hard time reaching the edges of the garden. 

The keyhole garden was invented and used by missionaries in areas of frequent drought or natural desert conditions, mainly places such as Africa, where this style of garden is still being used today. These gardens give people a way to feed their families healthy, sustainable food even in the middle of a drought or economic trouble. A keyhole garden has the ability to use very little water (only a gallon a day in slightly cooler weather), especially if you make a cover for your composter. This prevents the water from evaporating as quickly. 

Keyhole gardens also provide a significant amount of food for such a small footprint. I experimented with my garden this year; half of it I planted with the "correct" amount of space between plants and on the other half I crowded them purposefully. The side that I crowded did significantly better due to the fact that the crowding allowed a natural shade and mulch environment which aided in water conservation for the plants.

Read the whole thing, including the instructions.