I got mine from High Country Gardens, and they said its hardy to zone 5. This is its first year in my garden, and I was growing it in our areas rock and clay soil with no problem. The only problem I had is that it was at the front of my border, and was the ugliest looking plant I had ever seen. I put it in a tall pot towards the back of my border, in Gardeners Gold potting soil. It is doing fine, but my hummer is ignoring it so far. Hope that helps a little, even though I don't know yet if it will survive the winter!

Thanks Judy.
Maybe it wasn't the growing conditions but digging rodents that got it - we have a lot of them. I may try some gravel in the planting hole.

I have grown it in the past with some success. Apparently it does require good drainage. Although I no longer have any, I believe that it makes an excellent hanging basket. The hummers loved it, especially in early spring. I would guess that it is too humid for it here in Georgia. I hope to try it again in the future.