Please can anyone give me any guidance as to how hardy or otherwise
Tibouchina is?
I have one about 2 feet tall. I have brought it into a bedroom.
A friend who has a sheltered walled garden in Bristol left hers out
all last winter, and has not done more than cover it with fleece in
this recent cold spell.
I do have the offer of an unheated greenhouse. Which would be better?

Pam in Bristol