I must say, I am more than a little shocked by this entire thread. I am in the first couple of seasons of building up my permaculture garden. Our winters are so extreme, and our growing season so short, that it would take me several more Springs to establish my garden if I didn't have a greenhouse to harden off plants. I lost several berry bushes and a fruit tree last year, in part because of the short season. My plants are all regional. My greenhouse is all recycled windows and wood and I hope to have a rocket stove heating it soon enough.