Cannas are exotic plants with flowers of varying colors including red, yellow, orange and pink. Their foliage (leaves) are broad like banana leaves and often have a striped or marble pattern. Cannas grow to between 5 and 8 feet tall, and are a dramatic addition to most home gardens. Cannas have rhizomes as their roots (similar to bulbs) and can grow new plants each year. However you may have to take extra care of the rhizomes in order for them to survive the winter and come back in the spring.
Bring cannas planted in containers indoors before the first killing frost. Check the plants for any insects so you don't bring those inside as well. Remove the insects by hand, or spray with a pesticide before proceeding. Wait for the foliage to finish turning brown and die off. Cut it all off right above the soil. Place the pot in a cool, dry location such as your garage or attic.
Cut off the foliage of cannas planted in the garden. Wait as long as possible to do this, but definitely before the first freezing frost. Leave a couple inches on each plant still intact. If you live in an area with mild winters, covering the area with several inches of mulch may keep the rhizomes warm until spring.
Dig up the rhizomes in areas with extremely cold winters. With a spade or shovel, dig into your soil several inches away from each of the remaining plants. Dig about 8 inches deep and form a circle around the plants. Then carefully pull the shovel handle toward you. Do this around the perimeter of each plant until the rhizome is lifted out of the ground.
Shake off and remove extra dirt. Do not wash or scrub or you may damage the rhizomes. Lay the rhizomes onto some newspaper in a warm and dry location, such as in your home. Leave them out for a day or two to dry.
Place the rhizomes in a brown paper bag, mesh bag or in a container with a small amount of moist peat moss. Store them in a dark cool place, such as in your garage.
Check on the canna rhizomes every few weeks during the winter to be sure they are not drying out. If so, mix in another handful of moist peat moss. If you notice any rhizomes rotting or getting soft, throw them out.