If you told most dirt gardeners that you could grow corn, tomatoes and hot peppers in 2.5 cubic foot boxes on a concrete patio, they wouldn’t believe you.
These photos from the Picasa album of JHWMSU tell the story. The concrete patio “gardens” are EarthBoxs or sub-irrigated planters (SIPs, aka self-watering). Locate them anywhere in the city where there is adequate sunlight and security.
You can buy SIPs like the EarthBox, Tomato Success Kit, Garden Patch Grow Box or make them yourself from water tight containers such as utility buckets and tote boxes. All of them employ a very basic system of reservoirs and capillary action wicks.
The best way that I know to learn how SIPs work is to grow some windowsill plants (herbs for example) in recycled pop/soda bottle planters. They are a great teaching aid because unlike clay pots everything is visible.
The hundreds of photos in my pending file clearly show the significantly more widespread use of SIPs in the summer of 2009. Thanks to the Internet and bloggers, the growth in this market is exponential.