Question: I have two lilac bushes; both are about three-years-old.

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. Cut back about a third of the branches. Jul 08, The general shrub pruning rule is to cut no more than a third of the stems each year. 2  That will help the plant remain constantly vital, with new stems developing as old stems bloom.

Your goal is to have a lilac bush that has somewhere between eight to 12 stems of various ages, all of them between 1 to 2 inches in diameter. Apr 27, When pruning this way cut out any dead or weak canes, then cut out 2/3rds of the suckers or shoots coming up at the base, leave 1/3 for future blooming stems. You can actually dig the suckers up and pot them to make more lilacs if you wish, they actually mature faster than taking cuttings and rooting shrubmulching.bars: Jul 14, How do you prune lilacs?

There are several techniques involved in pruning a lilac bush: Get rid of dead, broken or diseased stems first, as well as any weaker branches.

In addition, cut branches to prevent rubbing or crossing. Remove old stems that are thicker than two inches. This prevents your lilac from growing too tall and encourages the growth of young shoots.

The stems should be Estimated Reading Time: 2 mins. Pruning of the old flowers, shoots, suckers, runners, and leaves aid in better aeration of the lilac plant, and also promote new growth on it. Generally, old branches are woody and hard. You might need a sharp saw to cut them down. Remove the Old Wood: Remove the old wood every shrubmulching.barted Reading Time: 4 mins.