How Many Times Will a Lilac Bush Bloom?

Superba

• Superba littleleaf lilac (Syringa pubescens, ssp. microphylla "Superba") can grow to be a shrub 6 feet high and 10 feet wide. It has rose-pink flowers in mid spring and, under the right conditions, blooms again in late summer. It is best to remove spent flower heads immediately to encourage new flowers. It grows from U.S. Department of Agriculture planting zone 4 to zone 7, but summer blooms are sporadic to non-existent where summers are hot. It is the oldest reliable reblooming lilac.

Josee

• The Josee lilac (Syringa "Josee") is a dwarf lilac, growing from 4 to 6 feet tall, with very fragrant lavender-pink flowers. It was developed in France in the 1970s and grows and reblooms as much as four times in the cool weather of the Pacific Northwest and Canada. Where summers are hot and muggy it rarely has enough flowers in summer or fall to be showy. The flower heads need to be removed for it to rebloom.

Penda

• Tom Wood developed Bloomerang (Syringa "Penda") for the Proven Winners Brand in 2009 and it does seem to be an improvement over other reblooming lilacs. It is small, 4 to 5 feet tall and 3 to 4 feet wide, and has its first flowers in late spring. It can start blooming again in midsummer and may bloom until the first frost. Hot summers may mean it blooms later but it should still rebloom when the weather cools off.

Encouraging Reblooming

• Lilacs can grow in partial shade, but flower best in full sun. They prefer a loamy neutral to slightly acid soil for the best flowers. If the shrub needs to be pruned it should be done immediately after the spring flowering to avoid removing new flower buds. A small amount of slow release fertilizer can be applied in the spring. Do not fertilize after early summer as it may encourage tender growth that will freeze in winter.