Alan Gabriel wrote:

I leave mine outside planted in large eathernware clay pots with Hostas
amongst them. Stood on the patio where I can keep an eye on them they do
well and I find here in North Bucks they grow very well

They have been ouside for over two years now and are bulking up nicely. I
must empty the pots, next Spring, when the hostas start to show. They are
getting overcrowed and the quality of the Cannas is suffereing. I'll thin
them out and replant some of then in the garden, others I'll in pots with
plenty of slow release fertilizer next
Spring. and use spares as dot plants when the bedding is starting to go
over.

I grow mine in earthenware pots. In the winter I move them into a cold
greenhouse and give them minimum water. I split them every spring,
giving the new plants to friends, family, neighbours etc. Last winter my
son left his pot of cannas out in a sheltered part of the garden
unprotected - they survived but were a bit late flowering. We are both
in North Bucks as well.

Keith