As with hanging gardens and vertical gardening, these methods allow food to be produced on top of contaminated soil, or where permanent hard surfaces have been laid, paved areas, disused parking lots, building sites, tennis courts, rocky sites, tops of building, balconies etc.
It also allows people with physical disabilities to participate in gardening, as they do not have to bend down.
Keyhole gardening is a self-feeding system: the compost tube in the middle allows the nutrients to leach into the root system around it, and also allows easy access from all sides. They can be made from alien timber, waste wood, stones or any other available material. They are an ideal system for restaurants, homes and institutions to recycle compostable material and develop food and herb gardens, limiting the amount of waste going to landfills.
The CWBR is on a program to develop these in Stellenbosch, Paarl and Franschhoek.