Peter Schneider in his book, "Right Rose, Right Place", lists it as being hardy to Z5.

Available from - colchester

I am personally very fond of this rose. It is constantly blooming for me. My plant is own-root, but I'm going to have it budded on root stock to see how that changes its height and vigor. I'd very much hate to lose it, as it isn't easy to obtain. The blooms are long-lasting and full, and it's a very attractive plant.