Cannas are tuberous rooted perennials that are native to the tropics. There are dwarf varieties that grow about two feet tall, and tall varieties that grow 3-6 feet tall. Cannas are quite tender and you should dig and store the roots after the foliage withers and dies back. Shake the excess soil off the roots and store them in dry sand, peat moss or sawdust. The roots will be dormant and won’t require water, but should be protected from complete desiccation. Check the stored roots during the winter and add a little moisture to the peat moss if the roots begin to shrink or shrivel up.
You can store canna in a garage or cool, dark basement. Wherever the temperature is above freezing, but below average household temperatures. Plant them in rich, moist soil in the spring for bloom by early summer.