Canna plants, tropical perennials more commonly known as canna lilies, produce large, attractive blooms in shades of pink, yellow, orange and red during midsummer to early fall. Canna lilies also produce large, ornamental leaves that resemble those of banana plants. Winter hardy in USDA zones 8 through 10, canna rhizomes may remain in the ground all year in these areas with proper mulching. In cooler zones, the rhizomes require lifting and overwintering indoors, or they may perform as annuals. Valued for their hardiness and tropical appeal, canna plants will grow in most areas of the country with only minimal care.
Plant canna plants during mid- to late spring after the risk of frost has passed. Choose a planting site that consists of well-drained, moist soil and receives full sunlight. Spread a 3-inch layer of peat moss over the planting site and use a garden tiller to incorporate the material into the soil prior to planting.
Dig a hole at the planting site about 3 to 4 inches in depth. Insert the canna rhizome into the hole and gently backfill the hole with soil. Water lightly to compact the soil around the rhizome. Space canna plants at least 18 to 36 inches apart to allow adequate room for mature growth.
Water canna plants once every week during the first year of growth to help establish the planting. Decrease the frequency of watering thereafter to once every 10 to 14 days, or once per week during periods of extreme heat or drought. Soak the soil to a depth of 6 inches to ensure the rhizome absorbs enough moisture.
Feed plants once per month using a balanced 10-10-10 NPK garden fertilizer. Apply the fertilizer according to the manufacturer's instructions for the best results. Water lightly prior to each application to prevent root burn.
Dig up canna rhizomes during fall after the first hard frost of the year. Store the rhizomes in an open container filled with peat moss in a well-ventilated, warm room for the duration of winter. Replant the rhizome the following spring after the danger of frost has passed and resume regular care.