This is just a peek at these beta test planters located at Liberty Sunset Garden Center in Red Hook, Brooklyn. There will be more photos to come, but you can easily understand the method from just this look.
Those are sections of 4" diameter corrugated high-density polyethylene (HDPE) drain pipe wedged down at the bottom of the planter boxes, which are lined with sheet plastic. The sheet plastic will line the planter all the way to the top on the next planters. What was done here was the result of a miscommunication with the planter builder.
There are slots around the periphery of the drain pipe that provide for both air and water flow. The drain pipes form instant water reservoirs and air chambers. The fill pipe in the corner is made from recycled water bottles. There is an overflow drain hole not shown in the photo.
All you need to do is add the media, plants, sunlight and nutrients. This method can be used in any watertight container including tote boxes.
It has the potential to revolutionize home and community gardening. Sub-irrigated planters (SIPs) will out produce any other method, including in-ground growing, while saving water and time. They also overcome the widespread and often undetected problem of contaminated city soil.