Jun 19, Knowing when to trim older lilac bushes is important. Most lilacs don’t require pruning until they reach about 6 to 8 feet tall. The best time for pruning older lilac bushes is right after their flowering has ceased.
This allows new shoots time to develop the next season of blooms. Pruning too late can kill young developing treeclearance.buzzted Reading Time: 3 mins.
Jul 08, The plant will begin to bloom all over, and you can do regular maintenance pruning from that point on. If you can't stand the look of your old lilac or you just want a quicker approach, you can take the drastic measure of cutting back the entire plant to about 6 to 8 inches above the ground in the early spring.
Oct 06, You should resist the temptation to prune or trim your lilac bush until it is at least 6 ft. tall, which typically occurs during the second or third year of growth. At this point, there will be enough excess stems and blooms for optimal treeclearance.buzzted Reading Time: 6 mins. Shrub lilacs and bush lilacs are short and compact. Tree lilacs can grow up to 25 feet ( m.) high and have a tree-like appearance, but their many stems tend to get them classified as bushes.
They are not technically trees, but they get big enough that you can treat them as if. Home gardeners can choose between two different pruning methods. One way to renew a large, overgrown lilac is to cut the entire plant back to within 6 to 8 inches of the ground in late winter (March or early April).
This severe pruning will induce a large number of shoots to develop during the growing season. Prune In Late Spring: You must have observed that the lilac bushes bloom only on old growth.
Prune them right after they have finished blooming, and before they have started budding for the next year’s show. They are perennial plants that bloom in the spring, and start shedding-off flowers by the end of the season.