Posted: 15/11/2016 at 15:47
I live in the south west as well and I grow my cannas in large tubs and bring them in, I store them nearly dry in the pots in the summer house. I did leave some in the ground to see if they would over winter but no success so be sure and bring them in.
Dahalias I leave in the ground with a thick mulch on them, I feel they make better plants if you don't keep lifting them.
Im on free draining soil if your soil is clay you will proberly have to lift your dahlias they will rot if they are standing in water.