enjoying this discussion. . . I'm finding this discussion very satisfying. Amongst permaculture practitioners, so it should be. As for taking a PDC course, the policy of 'buyer be aware' is solid. And people are living' growing, maybe not growing, and changing too, so it is good to do some research. I have found an online course offered through Oregon State University, by Andrew Millison. It is an Advanced PDC and OSU calls it Hort 485.