Blue Salvia

Fantastic shade of blue.

How i love BLUE :D

Is this one hardy?

Sid, Read my blog here on plant hardiness if you will.
Salvia are herbaceous and if they have not been sitting in cold boggy ground all winter they will return. Usually. If early summer is 'cold' they will arrive later (we've had some nasty May's after warm April's recently). But I would not suggest they will survive ANY winter down to -10C for example. They do prefer a sunny spot that is not soggy all winter and they will prefer a spot out of the wind between a couple of shrubs for example.

I see why you mentioned Salvia when I was rhapsodizing about blue Lobelia. I find that often when a plant is labelled blue it is more of a purple than a true blue... but that is almost ultramarine...very nice.
perhaps I gave up on salvia too soon. Thank you Wellies.