Congrats on your can-do canna - such a great foliage plant for adding drama to the summer garden. You can wait until a light frost damages the leaves of your canna or you can get snippy with the plant at the end of September and use the leaves you cut down for indoor enjoyment. Either way, cut the stem to ground level, dig up the tuber and let it dry for a few days indoors. Then place it in a paper bag with some peat moss or a bit of damp wood shavings. You want to keep the tuber from freezing and from drying out but too much moisture will rot the bulb. Some gardeners store the canna tubers on a tray and just mist them every month of so over the winter when they start to shrivel. Replant into potting soil around April but do not set outdoors until all danger of frost is past. Enjoy another summer of tropical delight. Keep growing, Marianne Binetti