Jul 08, When to Prune Lilac Bushes. Many of the newer lilac varieties grow quickly and might need pruning starting in their second or third year.
In general, by the time a stem reaches more than 2 inches in diameter, it should be pruned. If you are diligent with annual pruning of your lilac, the shrub will grow to about 8 feet tall with flowers throughout the branches. 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. 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 treeclear.buzzted Reading Time: 3 mins. As soon as the lilac bush's flowers are dead, trim each flower stem back to the leaves, removing all trace of the flowers.
This step stops the lilac from using its energy to make seeds. Lilacs should be pruned yearly to develop a good framework of stems and promote vigorous growth that enhances flowering. Yearly pruning consists of cutting diseased, misshapen, and unproductive stems to the ground. I also thin and remove some stems to encourage properly spaced, vigorous growth.