Canna lilies

I adore canna lilies and have others in pots which have excelled in what has been a very odd year in the garden. This plant was a star pupil last year so we overwintered it in a black bucket in a shed not really expecting it to survive the tundra blasts we had in February this year.
Surprise, surprise - it did and other than a visit from a very hungry caterpillar on one of the leaves it has flowered non-stop since June. We had an air frost Friday night/Saturday morning but not even that could knock its exuberance.