I'm sure Salvias would love your climate Nicola
Heres some info and tips on the RHS website:
http://www.rhsplants.co.uk/plants/_/salvia-amistad-pbr/classid.2000021328/It can grow to 1.2 metres and a spread of .5 meters so it needs a bit of space to show it iff.
I've grown that one before but it is now "expired"
I like the smaller Salvie x Jamensis varieties. I now keep some in pots and overwinter them fairly successfully in the old greenhouse.