Bill Mollison from Tasmania, Australia, is a researcher, author, scientist, teacher and naturalist. He is considered to be the 'father of permaculture'.
He takes us on a tour of his garden here and explains that permaculture is a way to develop a system that can go on forever. "Your work in planting is done after a year or so, and basically after that you become a forager."
Doesn't that sound great? He says: "Nature doesn't contain such a garden. It's incredibly rich in functional plants and in yields- higher than a monoculture system or nature itself."
"There is always something to eat, any time of year" he says, hand picking his next salad. Of course he is in a tropical climate- but growing food with these principles, on any scale, in any climate is well worth learning more about.