Sold as an annual or technically a "temperennial" here and unlikely to be considered winter hardy below a zone 9 (30F or 1.7C) and even that is pushing it. I know lots of things will grow in Cornwall that won't elsewhere in the UK so may be possible but the plant is not really frost hardy.

I was just wondering, as it is a beautiful plant. In its first year it flowers, but the second year it is much more floriferous.

By the way, your zone 9. 30F or 1.7C, cannot be right. 30F = -1.1C. and 1.7C = 35F

:-))))))

Got those figures off the USDA zone map so feel free to argue with them :-)