I was rather excited to hear about cold hardy herbs but looking at your location I guess I can see why. We have a few (haven't discovered which yet other than mint which is invasive) and I want to start an herb garden that will winter over here. I think in the ground would work better here. It takes a while for the snow to build up enough to bury the raised beds I have so until then there would be cold surrounding the boxes and roots therein.
