Do you think this would make a solid foundation (I'm in the same climate as you)? I'm also considering just doing Stanchions on the North wall that is to be 12' tall with larger support trianangles (roughly 6-7 feet). Then burying posts per your recommendation but adding anchor triangles to their backsides on the remaining sides. There will be horizontal cross supports that span the width of the greenhouse as well at 8' height. Any thoughts?
I read recently in "Biolshelter Market Garden" by Darrell Frey (great book!) they used a mixture of beeswax and turpentine painted on as a wood preservation. In your greenhouse book you don't talk about rotting as a large issue if you use the PSP method. Have you really had no issues with rot? Anyone have experience with homemade and non-toxic wood preservation?
I have been considering adding drain tile around the shoring to eliminate water issues but don't have the appropriate slope to "daylight" the pipe. I plan to angle the soil away from the greenhouse, and do the V shape mound on the North to divert surface water. Any suggestions for draining ground water away from structure?
Do you know any polycarbonate dealers in the North Idaho area or should I just order from Sundance? Anybody want to get in on an order from Sundance to cut shipping costs?