Do you mean Canna’s or Calla’s (Zantedeschia). Both are perennial but are generally not hardy in the UK, and need protection from frost. I keep ours in pots in our unheated greenhouse over Winter.
Cannas are perennial, but half-hardy, which means they only survive temperatures above freezing. It is not practical to collect seed as it is very slow to grow and genetically unstable. What I do is; every year when frost is forecast, lift a good plant and cut off the new side growth,then pot itup and keep it in a warm, sunny place over winter. As soon as it warms up again ( April or May, depending which part of the country you are in) you can plant it out. Remember Cannas are very greedy and need lots of warmth, water, sun and fertilizer. Good luck!
Posts
When you don't even know who's in the team
S.Yorkshire/Derbyshire border