If a bloom fades earlier in the season than the flowers 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. Remove spent blooms all the way to the stems to prevent seeding and encourage more blooms later on.

Nip off the long stems.

Cut back about a third of the branches. Apr 28, Doing an Annual Pruning 1. Cut fresh flowers in the spring. When lilac flowers reach their peak and are just this side of fading out, cutting 2. Nip off the long stems. Take a look at your lilac bush or tree and assess whether there are any extra-long but 3. Thin the lilac. Search for dead or 75%(4). Jun 02, How to Prune Lilac Bushes.

When pruning lilac bushes, you want the bush to be about feet high, but don’t just start lopping off the top of the bush! It’s best to cut the full stem, all the way down to the bottom. This will allow you to have a mix of new branches and older, blooming branches, and will keep your lilac bush happy and bushnotch.bars: 2.