I wonder if, like lavender, there may be many different types of Box. Some hardier than others. I have seen a couple posts lately from people who were talking specificly about these. One person had a big collection of them. Perhaps if you could find that poster they would know more about how to tell what kind and how hardy. I live in the Northern Willamette Valley, probably quite a bit warmer than you in the winter, but mine have lived through several ice storms with no harm. I have seen them get burned from too much intense hot sun though. This sounds like a question for "BBOY", if you cant find those other posters. He seems to know a tsunamie of stuff about plants and zones:)

I'd be inclined to think Zone 3 was too cold. Yes, there are many kinds of box. American Boxwood Society has published an entire encyclopedia of box.

Yep, I was right. Nice Tsunami, and gracious too... :)

It is my understanding that the Canadian hardiness zone system differs a bit from that of the USDA. Canadian zones are stated one zone lower than the corresponding US zone. Therefore, a Canadian zone 3a is comparable to a US zone 4a.

Zone 4 is generally considered the lower end of boxwoods' range of hardiness - at least for the very hardy Korean box - but individual microclimates may increase this slightly. But even the very hardiest of box (B. microphylla var. koreana or the 'Green" series of hybrids developed in Southern Ontario) can be expected to experience some dieback and the rather unpleasant bronzing or discoloration of foliage in that cold a climate.

Maybe try this one, if you haven't already.

Here is a link that might be useful: Gardening in Canada

Thanks everyone for the suggestions and info.

I guess the boxwoods will just be a bit of an experiment for us...too bad because they really are a nice looking plant.

J.