Canna lilies grow from rhizomes that spread underground. The plants grow from eyes on the rhizomes, with each eye capable of producing a new plant. The most common propagation method involves dividing the rhizome into pieces. Canna lilies also grow from seed, but this method is used less often because of the ease of dividing the rhizomes.
Propagation of Canna Lilies by Division
Dig up the canna rhizomes in the fall after a damaging frost. Cut the plants back and dig up the rhizomes. Shake off excess soil or gently wash soil away with a garden hose.
Hold the rhizome in high humidity for a few days to cure the root and avoid drying.
Place the rhizomes in a box of moist sphagnum moss or vermiculite and store in a cool place until spring.
Divide the rhizomes in the spring, before planting. Each tuber contains a clump of rhizomes with several eyes. Break the rhizome into sections, leaving one to three eyes per piece.
Plant the rhizomes 12 to 18 inches apart and 5 inches deep. Start pieces containing only one eye in a small pot and transplant them to the garden when the plant is established.
Growing Canna Lilies from Seed
Collect seed from spent flowers. Soak the seeds for one to two days. Nick the soaked seed with a file or knife edge to speed up germination.
Plant the seeds in peat pots or small pots with seed starter mix. Keep the soil moist. Seeds germinate in one to two weeks.
Transplant the canna lilies to the garden in the spring.