How To Prune Forsythias & Lilacs Plus a Sweet New Annual

After lilacs flower and then the flowers die, you have two weeks to prune. After that two week period the plant starts to produce next year‘s flower buds. This is why we don’t prune in the fall or in late winter early spring because you’re cutting the flower buds off. Rejuvenation pruning old lilac trees means removing the old thick stems and allowing new stems to take over and mature to become the future of the tree. Older, thick stems are more prone to disease, and they produce less flowers. T