In this video, Daniel Catalaa of San Francisco explains the design for a planting pot which combines the benefits of self-watering and self-feeding in a single unit. This is not a new idea, but a combination of two existing ideas into a single unit. It has a large water storing capacity and uses earthworms to create and spread compost in situ.
It will take roughly about six hours to build it at an approximate cost of 100 dollars. The benefits of this design are free fertilization, plants stay watered when you are away and the device produces excellent yields.