When pruning a lilac after it flowers, do I need to cut off.
Jul 08, How to Prune Lilac Bushes Regular Maintenance Pruning. The general shrub pruning rule is to cut no more than a third of the stems each year.
2 Rejuvenation Pruning. Older lilacs can have stems as thick as small trees and will flower only on. Apr 02, How to Prune Lilac Bushes. When pruning lilacs, cutting back the tops of overgrown stems is oftentimes not enough. It is generally better to cut the entire stem.
Trimming lilacs is best accomplished using clippers.
Left on their stems, the flowers will die but continue sapping energy that could be spent on new growth.
Remove spent blooms all the way to the stems to prevent seeding and encourage more blooms later on. Cut back about a third of the branches.