Great question for the fall season. Enjoy your cannas until the first frost blackens the foliage then dig up the fat tubers, cut off the stem and leaves and place the bulbs in a garage or shed that is frost free. After a few days or when the tubers have dried out a bit place them into a paper bag with some dry peat moss or dry wood chips. The tubers need to be dry but not too dry.  Keep them in a cool, dry spot all winter. About six weeks before the last frost in your area you can pot up the bulbs but keep the containers indoors near a sunny window as any frost will damage the new growth. Once the soil is warm in June you should see foliage popping up. Your potted bulbs can go outdoors when there is no frost or you can replant the overwintered tubers into the ground in late spring. Just remember that these tropical tubers like warm soil and so don't set them out too early. Fertilize as soon as you see foliage.  Keep growing, Marianne Binetti