They claim to currently have the largest crater garden in North America, at 22,796 square feet.
The garden follows the meta-pattern of ‘Concentric Circles.’ The lowest circle, at the bottom, will act as a pond in the wet season. Water will be able to ‘wick’ upwards to feed the roots of plants in the higher levels of the crater. As trees and plants mature, micro-climates form within the crater, allowing for the planting of shade/sun loving plants and/or wet/dry loving plants in distinct areas.
They also claim that Crater Gardens are an ‘Area Force-Multiplier,’ and that by adding multiple layers into an otherwise flat area of land we are able to grow, “Massive quantities of food because of a multi-layered growing space.”
This also follows the permaculture design principle of ‘maximizing edge.’
See more on Sepp Holzer here: http://www.holzerpermaculture.us/