■ Propagation from seed is very slow: the seeds take months to germinate and the seedlings are slow to mature into flowering plants.
■ Division of the rhizomes is easier and quicker, as well as more reliable.
■ The best times to divide plants are spring, soon after flowering, and autumn.
■ Choose the healthiest, strongest pieces from the edge of a clump, and replant promptly after splitting, to avoid drying out.
Replant divided rhizomes as soon as possible