The blooms of a lilac tree may well be affected.

Apr 02, The best time for pruning lilac bushes is right after their flowering has ceased. This allows new shoots plenty of time to develop the next season of blooms. Pruning lilacs too late can kill young developing buds.

If you are in any way uncertain about how to maintain the beauty of your common lilac bush or hedge, you wish to enhance its flowering capabilities, or you want to renovate a lilac that has been left unpruned for some time, if is often best to call in the professionals.

If you are pruning lilac trees or shrubs entirely to within inches of the ground, it is best to do so in early spring. Lilac trees that are over three years old can safely have these removed as close to the ground as possible. Do this from mid-June onwards. For new lilac trees in their first year, remove all the forming flower buds before they start to bloom. This is usually around the first week of bushdig.barted Reading Time: 6 mins.

Jul 08, The time to prune mature lilac plants is just after the flowers have faded in the spring. Lilacs set next season's flower buds almost immediately, so late pruning will mean sacrificing the next year's flowers. 1  Pruning early also gives new shoots more time and energy to develop, ensuring plenty of blooms for the following spring.