Canna lily bulbs, or rhizomes, are an easy addition to most bulb gardens. A perennial flower, the canna hails from the tropics and is not cold hardy. You must dig up the bulbs each fall in areas that have freezing winter temperatures and replant them again in the spring after all danger of frost has passed. In areas with mild winters they are left in the ground year around and may reach their full height of 5 feet or more, though in most climates 1 to 2 feet is more common.
Prepare a well-drained garden bed that receives morning sun. Lay a 2-inch to 3-inch layer of mature compost over the planting bed and till it in to an 8-inch depth to provide organic matter and nutrients to the canna plants.
Dig planting holes 4 inches deep and space each hole 1-1/2 to 3 feet apart. Set a single rhizome in each planting hole with the buds facing upward, then refill with soil and lightly tamp it in place.
Water the bed thoroughly immediately after planting so it is evenly moist throughout. Continue to water the canna bed weekly, providing 2 inches of water per plant.
Fertilize once a month with a low-nitrogen fertilizer. Follow label instructions for exact application amounts.
Allow canna to die back naturally in the fall. Cut back the stems to 3 inches once the foliage turns black and dies, usually after the first frost. Dig up the rhizomes and store inside at 40 to 50 degrees until spring replanting time returns.