Here is an example of an old lilac tree that was rejuvenation pruned. They removed only about a third of the plants live wood/leafy canopy. you can take more than a third if you want to as long as your lilac is old and established, but if you take more than a third, you shock the plant so much that it doesn’t have enough energy to make flowers for next year. You could take the entire plant to the ground, every single stem and it will regrow, but won’t bloom for at least three years. I can’t alwa