I have asked this question before, but here goes again -- I have been told Spring, Early Summer, Fall. Our new landscaper says Fall, he means early Fall I believe, and stressed doing it when it cools off a bit. It's very hot in Victoria BC right now -- Saanich, actually. He think they will be heat-shocked. This is a question relevant to stratas, which often have quite a lot of cedar hedging. We hate to leave it looking so hairy at the moment, but want to follow his advice. I have consulted web pages and gardening books and they all say different things, I suppose for different climates.