Caring for Canna Plants
- Cannas are prized for their large, colorful flowers.canna flower image by Alison Bowden from Fotolia.com
Cannas need a rich soil with plenty of organic material. Before planting the rhizomes, work about 2 inches of well-rotted manure into the soil. This will enrich the soil with enough nutrients for the growing season, and it will also help the soil hold moisture. If this is not practical, use a good bulb fertilizer monthly beginning early in spring. - Plant cannas where they will receive lots of water.canna indica image by J??rgen Hust from Fotolia.com
Cannas need a lot of moisture, and they do well planted around garden ponds and in low, damp parts of the garden. They also do well in borders as long as they get enough moisture. Water cannas planted in borders twice weekly when it does not rain. A layer of mulch will help the soil retain moisture. - To keep cannas blooming through the season, cut off the portion of stem that holds faded flowers. If these flowers are not removed, the plant will put all of its energy into making seeds rather than flowers. Once all the buds on a stem have bloomed, cut the stem and surrounding leaves down to ground level. This will allow other flower-bearing stems on the same clump to get more light, and will reduce crowding and competition for nutrients.
- Growing cannas in containers is a good solution in areas where it is impractical to amend a poor soil, or where there are problems with soil-borne insects or diseases. Use a plastic 5-gal. pot similar to those in which potted shrubs are sold. Bury the pot filled with soil in the flowerbed with about an inch of the top exposed, and then cover the exposed top with mulch.
Growing plants in containers helps conserve water because you will be watering only the plant, and not the surrounding soil. When using a bulb fertilizer, follow the label instructions for container-grown plants. - At the end of the season, dig up the clumps to prepare the rhizomes for winter storage. Although cannas grown in USDA zones 10 and warmer can be left in the ground over winter, it is a good idea to dig up the clumps anyway to rejuvenate the plants and keep them from becoming overcrowded.
Discard old rhizomes that do not have any eyes. Clean off the remaining rhizomes and rinse them in a solution of one part household bleach to nine parts water to kill any diseases they are harboring. In areas that do not experience a hard freeze over winter, the rhizomes can be replanted right away. In colder areas they should be spread out in a cool, dark place to dry for a week or so. Once they are dry, remove any remaining roots, place them in a flat box, and cover them with peat moss. Store the rhizomes at temperatures above 45 degrees.
