My old contraption completely disintegrated. I bought these plane simple boxes from Office Max or something. They were inexpensive. However, after a couple of years under the sun the plastic became completely brittle.
Enter EarthBox. I found it while searching for the new planting ideas. It claimed to be made from better UV resistant plastics. It also has a water reservoir under the layer of soil. It should keep the plants more hydrated and thus produce better results. There are many DIY EarthBox-like designs – essentially get two plastic boxes and some PVC pipes and you are done. But I figured that factoring work and the materials needing replacement in a couple of years I won’t save much.