Cannas, also known as canna lilies, grow natively in tropical areas of the Americas. Gardeners value the plants for their ease of care, bold foliage and colorful blossoms that appear in mid-summer through fall in shades of orange, red, yellow and pink. Cannas reach up to 10 feet in height in the home garden, depending on the variety. Hardy in USDA zones 8 through 12 only, canna rhizomes must be lifted from the ground during winter in all other areas of the country. The tropical plants require warm temperatures to thrive and cannot tolerate freezing, but are otherwise undemanding.
Plant cannas during spring as soon as the soil has warmed and all danger of frost has passed. Choose a planting site that receives six to eight hours of full sunlight and consists of fertile, well-drained soil.
Use a shovel to dig a hole for the canna rhizome about 3 to 5 inches deep. Insert the rhizome into the hole and gently cover with soil. Water immediately to collapse any air pockets in the soil. Space cannas 1-1/2 to 3 feet apart.
Water cannas once every 10 days during spring, summer and fall to prevent the soil from drying out completely. Increase watering frequency to once each week during periods of extreme heat and drought.
Feed twice each year, once during spring and again in mid-summer, using a balanced 10-10-10 NPK fertilizer. Water cannas both before and after applying the fertilizer to prevent nitrogen burn. Apply according to the manufacturer's instructions.
Dig up canna rhizomes during fall, just before the first frost of the season. Cut back the stems to 2 to 3 inches, remove the rhizomes and allow them to dry at room temperature for one to two days. Store in a box in a cool, dark location with temperatures between 40 and 50 degrees Fahrenheit. Replant during spring the following year.