Homemade Sub-Irrigation Planter Like The EarthBox and Grow Box

Last summer, at a farmers market, I met a photographer who was telling me about what it was like to be a professional photographer. As a gardener, his most interesting story was about traveling with a rock band ( I forget which one) that was socially conscious and liked to fund agriculture products in developing countries. They would start gardens in an Earthbox and auction them off at their concert stops. I'd heard about the EarthBox before and even the Grow Box before but the thought of these rockers starting gardens in them made them more appealing.