Several cordyline australis "red star" in my back garden have
snuffed it. The bark has died and fallen away in places from the
base of the stem and the root has what looks like woodworm holes in
it. Any ideas how I can prevent this happening in the future?
Also for the second year running due to bad weather my musa basjoo
has been cut right down to the ground, only this year I can't see
any signs of life. Is it possible that the second harsh winter in
succession has done it in?

Thanks.