| This gets confusing, but I believe there are generally two schools of thought on the Canadian zone ratings versus USA zone ratings. The first is that the zone ratings are different, but not to a huge degree. That is, Canadian zone 4 is roughly equivalent to USA zone 4. I find this rule to be the easiest to follow and for a lot of plants it seems to work. The second school of thought is that there is a difference, but I thought it was the opposite. That is, Cdn zone 5 equals USA zone 4. Unless I'm not thinking correctly. That is, if you live in zone 5 Canada and want to buy a shrub using the USDA ratings, look for one's hardy to zone 4. Maybe this is just meant to ‘be on the safe side’ Of course, all is not an exact science so, the only way to know for sure is to try the plant in question. Trees that are hardy to one zone don't necessarily automatically die just because they are placed in a colder zone. They may suffer more dieback. If dieback is severe, they may grow more shrub like than tree like. Or if really severe it might kill them eventually. If you have the time and patience, starting from seed might be a cheap way to experiment. I know Angelgrove tree seeds in Newfoundland has beech seeds (www.trees-seeds.com) Personally, I’ve always wanted to try a tri-colored beech. Glen | 
