What are the cultivation methods for canna lilies?
The canna lily is native to tropical regions such as the Americas, India and the Malay Peninsula. It likes warmth, moisture and plenty of sunlight, and is not cold-tolerant; it fears strong winds and frost. It is not demanding about soil and can tolerate poor, thin soil, but grows best in fertile, moist, well-drained soil.
After the plants wither in late autumn, cut off the above-ground parts, dig up the rhizomes, dry them in the sun for 2-3 days, and bury them in sandy soil in a well-ventilated greenhouse. Do not water them, keep the temperature above 5°C, and they will safely overwinter. In areas south of the Yangtze River, the rhizomes can also be left in the ground over winter; simply cover them well with added soil, and they will still sprout again the following spring.
The canna lily is highly adaptable and fairly low-maintenance in terms of care; it is not delicate, and has very few pests and diseases. From May to August each year, watch out for leaf-rolling caterpillars, so that they do not damage the tender leaves and flower spikes. You can spray with 50% dichlorvos diluted 800 times, or 50% fenitrothion emulsifiable concentrate diluted 1000 times, to control them.
Canna lilies grown in the ground occasionally attract cutworms, which can be picked off by hand, or controlled by drenching the soil around the roots with trichlorfon diluted 600-800 times.
Propagation of the canna lily: canna lilies are mainly propagated by division, and can also be grown from seed.
Division is carried out in March-April. Dig up the old rhizomes and cut them into blocks, keeping 2-3 buds and some fibrous roots on each piece. Plant them about 10 cm deep in the soil, with a spacing of 40-50 cm between plants, and water them thoroughly. When the new shoots have grown 5-6 leaves, apply a dose of decomposed manure, and they will flower the same year.
Canna lilies are less commonly grown from seed; this method is used only when breeding new varieties or propagating on a large scale. Sowing is generally done in a greenhouse in March-April each year. Because the seed coat is hard, you should cut through the shell with a knife before sowing, soak the seeds in warm water at 25-30°C for one day, and then sow them, which makes sprouting easier. If the temperature is kept at around 22-25°C, they will sprout in one week; once the seedlings have grown 2-3 leaves, transplant them.