Apr 18, Chop your entire lilac bush down to 6–8 inches (15–20 cm) if necessary. If your bush is severely overgrown or if it is not flowering properly, you may need to do a more severe pruning. Cut the entire bush down to 6–8 inches (15–20 cm) high%(7).
After your lilac bush has finished blooming, spread some lime and well-rotted manure around the base. Trim the bush to shape it, and remove suckers at the same time. Pruning Lilacs. Lilacs bloom on old wood, so it’s critical to prune in the spring right after they bloom. If you prune later in the summer, you may be removing the bushtrim.buzz Type: Trees, Shrubs, and Vine. May 10, Of significantly larger stature is the Japanese tree lilac, S. reticulata, growing 20 to 25 feet high at maturity.
This is a pest free, low maintenance tree that grows more attractive with the years. The cultivar ‘Ivory Silk’ features a profusion of upright panicles of Estimated Reading Time: 3 mins. Lilac Pruning. Pruning is an essential part of lilac care. The key is to prune them after flowering, since next year’s flowers are produced in the summer. Older, leggy stalks can be cut to the bottom of the plant, while younger shoots should be cut back by approximately half.