I have had Fagus sylvatica 'Dawyck Purple' for 3 years in my zone USDA zone 4a garden. Last year I had one branch die back a little, but last winter was really, really tough on woody plants.

If I remember correctly, the US and Canadian zones are not the same. Canadian zone 4 is equal to USDA zone 5, so you should be OK if you plant a copper beech ***in a protected spot*** in Canadian zone 3. Copper beech is normally rated for USDA zone 5.
Good luck,
Mike

We are looking for a copper beech to plant here in Northern Ohio. Any leads out there as to where to find a good sized (2-3 inch) tree with an Ohio climate in mind? Also, we are looking for a leatherwood bush...Dirca palustris... any ideas where to find that?

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 Âbe on the safe sideÂ

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, IÂve always wanted to try a tri-colored beech.

Glen