Most will winter over indoors as house plants if given adequate light. Place all other pots well below the freezing level for the winter. A bird bath deicer may be used to keep whiskey barrels from freezing in the winter, and will act as a bird bath at the same time. It is all right to trim off any dead or dying leaves for the winter except for some marginal uprights, especially cattail . For adequate aeration of the rhizome, cattails, Arundo , canna, and water chestnut should have their old growth left intact until new growth has come up the following spring.
True cannas do best if cut back and overwintered out of water in a frost-free place like a garage.
They are unobtrusive and work quite well. You can put it on a timer or photo-sensitive cell to work only at night. Ponds 3 or more feet deep with straight sides are some protection against raccoons and fish-eating birds.