I would think that it probably is in zone 6. I tried it in zone 5 and it almost made it.....but not quite.

could someone tell me what zone 5 and 6 are or am i just stupid.[no dont answer that last bit please].i have a lithodora 'heavenly blue .

In the US and Canada the countries are mapped out into hardiness zones, also known as climate zones or growing zones. The countries are big enough that one area can have totally different weather and temperatures than another. The lower the USDA or Canadian Hardiness zone number, the colder and more severe the weather. Zones, as far as I know, range from 1 (the coldest) to 11 (the warmest) in North America.
I'm in zone 5 and we have winter temperatures -29 to -23 C (-20 to -10 F). Zone 6 would have winter temps -23 to -18 C (-10 to 0 F).
As far as I know, most of England is equivalent to a zone 7.
Hope this helps.

thanks for that gilli
i thought it must be something along those lines but wanted to check.
glad i live in the uk,i dont do cold very well.