Kelton, we've been pretty close to zone 8 for a while here in Knoxville. Surrounding areas probably fall more solidly into zone 7, but near downtown you'd be pretty close to the zone 7/8 border.

The problem with our weather though is not so much about what the average minimum temperature is, but more about the pattern of the weather warming up mid-winter and then snapping back to cold. I've heard predictions that that may become more and more common for us, but I'm not sure of the details about why. It sure doesn't sound fun.

To find your official zone info, just look at the USDA's map, HOWEVER their designation for near downtown is much more conservative than the real numbers suggest (if you use the old formulation, which they don't now).

Here is a link that might be useful: USDA Hardiness Map