I don't think it's possible to over water most canna. If you have a sandy soil, you will probally have to water daily. If you have pretty rich soil, maybe a deep watering once or twice a day. Mulch helps too! I do know that the more you water them, the more they grow.

Hey, thanks! I'm curious about this, though:

"If you have pretty rich soil, maybe a deep watering once or twice a day."

Once or twice a day?

(They'll probably get it once daily to start. New garden soil down this year (3 new inches).

Let me fix that! Once or twice a week. I'm sure the plants wouldn't mind twice a day, but you might when the water bill comes. :)