May 20, New lilac bushes don't require maintenance pruning until they are about 6 - 8' tall. The time to prune mature lilac plants is just after the flowers have faded.
They set the next season's flower buds almost immediately, so late pruning will mean sacrificing next year's flowers. Mar 26, When's the best time to trim lilac bushes? Answer + 3. Answered 6 answers. True, pruning early-flowering deciduous shrubs at this time will reduce or eliminate blossoming in spring that year, but the trade-off is in gaining healthier shrubs that will bloom more vigorously for the long run. Rejuvenation pruning is commonly done on overgrown lilac shrubs. They are one of the shrubs that respond well to this kind of pruning.
Jan 31, Plants; By Ret Asked on Jan 31, When is the best time to trim Lilac bushes?? Answer + 4.
Jun 23, When plants grow too big for their location, pruning can be an alternative to removal. Every rule has exceptions, but some basic principles apply that help simplify the pruning process: Early-blooming shrubs tend to set flowers on last year’s growth; these should be pruned as soon as their flowering finishes.