Cannas are tropical plants that grow from bulbs, or rhizomes. Canna flowers come in many colors, including orange, red and yellow tones. Cannas grow lush leaves, with some varieties having striking variegated leaves and others featuring deep green leaves. Although some dwarf varieties exist, most cannas grow to between 2 and 3 feet tall.
In zone 6 and colder, plant your canna bulbs in the spring after all risk of frost has passed. When planting the bulbs, use care not to damage them. First, loosen the soil to a depth of between 12 and 15 inches. Add a couple of inches of compost. Carefully dig a hole 4 to 5 inches deep slightly larger than the bulb. Lay the bulb on its side in the hole and cover it. Plant your bulbs between 1 and 5 feet apart, depending on the variety. Water thoroughly.
After planting your canna bulbs, care for them primarily by not allowing them to dry out. Once your cannas have sprouted, add 2-4 inches of mulch to help the soil retain moisture. How often and how much water your cannas need depends on your climate. In semi-arid climates, you may need to give your cannas a couple inches of water every day or two. In wetter climates, water less. Feel the soil with your finger. If the soil feels dry more than 1/4 inch deep, water your bulbs.
Caring for your bulbs in summer is similar to spring care. Keep the ground moist and mulched. As the flowers fade, remove them before they completely die. As summer temperatures increase, you may need to give your cannas more water.
How you care for your cannas in the fall will depend on your climate zone. In zones 7 and warmer, you can winter your cannas over in the ground. However, in zones 6 and colder, dig the bulbs and winter them over inside. In zones 6 and colder, cut back the foliage after it has been killed by light early frosts.
Loosen the soil around the bulb. Be careful not to damage the bulb with the shovel. Try to remove the bulb with protective dirt around it. Rinse the bulb and place it in a dark, dry 60-65 degree F room for 2 to 3 days. Store the bulbs in paper sacks.
Store your bulbs over the winter in paper bags. Keep the bulbs in a dry environment that is between 50 and 70 degrees F. Keep the bulbs in as little humidity as possible. Towards the end of winter, cull your bulbs by removing unusually small bulbs and bulbs that feel too soft. After culling, your bulbs will be ready for spring planting after the risk of frost has passed.