Looks like a gonner Sunshines. The red and variegated Cordies are even more sensitive to a bad winter than the green ones and I lost 5 in winter 2009/10 despite fleecing. There is a faint (very faint I am afraid) possibility that if the roots aren't damaged that a new growth will appear over the summer. If you want to try, and I don't hold out much hope, then you should cut it back after the last frost. The dead growth does provide just a little protection until then, and feed it a little. I am not organic so use superphosphate to encourage root growth but a good all round fertiliser would do.

Personally though I would dig them up and, if we are going to continue to get winters like the last 2 (and I bet we will) replace them with Phormium which, whilst having the bladed leaf growth, are far hardier. Or keep new ones in pots for over-wintering under glass.

hi sarraceniac thanks for your advice i will replace it with a phormium many thanks

I may be a bit late, but my red cordyline suffered the same fate last year, so I pulled up the rotten leaves in a tidying spree. Then I found a load of new shoots coming up from the base a couple of months later. Mind you mine weren't in pots, But Where I am they shouldn't really survive anyhow. May be worth a try.