When to Divide a Tree Lily Bulb
The best time to divide tree lily bulbs is in autumn, three to four weeks after blooming and, preferably, a few weeks before the first average frost date in your area, which allows time for the plant to establish healthy roots before the first cold snap. A cool, dry day is healthiest for the plant. Never divide lilies when the foliage is still green. As a general rule, divide tree lilies every two to three years to keep tree lily plants neat and healthy. Otherwise, tree lilies require very little care.
How to Divide Tree Lily Bulbs
Cut the stems down to 5 or 6 inches (13-15 cm.), then dig around the clump with a garden fork. Dig about 12 inches (31 cm.) down and 6 to 8 inches (15-20 cm.) from the clump to avoid damaging the bulbs. Brush off the dirt so you can see the divisions, then gently pull or twist the bulbs apart, untangling the roots as you work. Discard any rotted or soft bulbs. Cut the remaining stem just above the bulbs. Plant the tree lily bulbs immediately in a well-drained location. Allow 12 to 15 inches (31-38 cm.) between each bulb. If you aren’t ready to plant, store the tree lily bulbs in the refrigerator in a bag of moist vermiculite or peat moss.
