Hibiscus Rosa-Sinensis (rose of china)

[sawfish]

Can anyone tell me if it would be possible to grow these outside in Glasgow? Or is that a ridiculous idea.

I've read the plant is hardy to -6C, does this mean it could be overwintered outside in a mild winter?

[sawfish]

[Ceratonia]

They're tropical plants - find it hard to believe they'd survive any frost, let alone -6C. There are plenty of other hibiscus which are much hardier, but nowhere near as showy.

I tried over-wintering a couple in the (heated slightly) greenhouse but neither made it and I reckon Glasgow's probably a bit colder & darker in winter than here.

Seems like some people do keep them in greenhouses though - see

http://www.trop-hibiscus.com/gindr.html

[sawfish]

well found Ceratonia

[Barnowl]

I've seen Hibiscus against house walls in London but we don't usually get much below freezing here. I would think up North you'd need to bring it inside for the winter.