Asiatic lilies have large, dominant flowers that grow from scaly, underground bulbs. They are heat-tolerant, but dry seasons induce dormancy. Prune your Asiatic lilies carefully and frequently to ensure future blooming. To do so, you need clean, disinfected pruners and 20 minutes to an hour, depending on the number of plants.
Pinch off the flowers
Deadheading, or removing the dead flower, encourages the plant to bloom more when done during blooming season. Perform this action at the end of the season, as soon as the flower fades, to stop seeding and initiate dormancy.
Leave green foliage
When entering dormancy, Asiatic lilies use the energy from late season photosynthesis. Prune leaves as soon as they turn. Wait until the stems are brown before you cut them, and sever the stem at its base, close to the ground. Cut non-blooming plants when they yellow, and expect buds the following year.
Divide the bulbs
Perform bulb division every two to four years or when the beds become overcrowded and under-producing. Dig up the bulbs after the fall pruning and separate those that have attached. Replant the bulbs 18 inches apart in well-draining soil. Water them year-round to have flourishing and healthy flowers again.