Posted: 10/12/2013 at 17:35
Agree with fidget - they're best cut back and kept inside a sheltered porch or somewhere bright but where it won't freeze.
I leave mine in the garden (no sun in Winter, so can go down to -5 some days) but I cover them lightly with white carrier bags and chuck all the fallen leaves around the base. They are right next to a brick wall, planted in open soil, not pots. They overwinter fine. I tend to leave all the leaves on, as I find that as soon as they are cut, the water-filled stems will freeze very easily.
It may be too cold where you aren to do this though.