Canna plants are popular in many gardens due to their large green leaves and showy flowers in vivid colours. Cannas grow quite fast and can cover a garden area quite rapidly. Canna plants are the only plant in the Cannaceae family but are closely related to the Ginger and Banana families.
Canna bulbs or a rhizome, which is the technical name of the bulb, can be cultivated from other growing plants. Many people will thin out their present canna bulbs and either start a new planting area or give the bulbs to friends and family. The bulb is a large tubular root with smaller roots growing off it. One bulb can multiply and produce several plants after the first year.
Zone 7-10 Planting
It is important to consult the planting zones for Cannas. The United States and Canada have planting zones from 1-10, with the lower numbers in Canada and the Northern United States. Zone number 7 begins the areas where there is not as much freeze so the likelihood of ground freezing is not as great.
The best time for planting is in the fall. Plant the bulbs in the ground approximately 2 inches deep in the fall before the first frost for zones 7-10. Cover the bulbs with mulch to protect the ground from hard freezing. They will lay dormant until early spring when they will start growing. Allowing the bulb an early growing start by planting them in the fall will cause them to bloom early and will continue blooming throughout the spring and summer.
Zone 1-6 Planting
For zones 1-6, only plant cannas in the ground after the last freeze in the spring or start the bulbs indoors. Plant the bulbs in pots indoors approximately 8 weeks before the last frost and place them in a sunny location on a deck or sitting on the ground in the garden. This may delay blooming time as they will have a shorter growing season.
In zones 1-6, the canna bulbs will need to be dug from the ground with a hand shovel or brought indoors if in a pot before the first freeze. To store the bulbs for the next spring, wash all the bulbs, separate them into additional bulbs if desired, and place them in a plastic bag with peat moss. Puncture the bag several times with a fork or knife to create air holes so the bulb can receive oxygen. Place the bag with the bulbs in a cool, dark location for the winter.