Confessions of a Liberal Puritan

Yep, middle Tennessee has a very long growing season, usually (as well as a very long air conditioning season, usually starting before the end of March, though I think I made it almost through April before having to turn it on this year).

To be on the safe side, I try to stick to plants that are hardy through zone 6, though I suspect that the sheltered nature of my backyard makes it more like zone 7 at times, but you're probably, what, zone 4 in Idaho (http://www.usna.usda.gov/Hardzone/hzm-nw1.html)? (Depending on where in the state you are -- at least, according to that national arboretum map, there's a lot more diversity in growing season in your state than I'd expected.)