pruning lilac bush

Asked June 10, 2020, 3:00 PM EDT

I have a beautiful lilac bush that has never been pruned. I am learning that it should be pruned 1/3 each year. This bush has beautiful blooms at the ends of every branch and all branches appear to be dead in the middle, but with a flower on the end. How should I prune it? Or should I just let it go which is what they have done for years. I also have a couple lilac bushes that have "dead" center branches, but small amount of growth and leaves at the top. Should I cut the dead branches to the ground? Thank you for your help.

Hennepin County Minnesota

1 Response

Ordinarily, lilacs are lightly pruned right after bloom. They are pruned just to shape and to deadhead the old blooms.

However, older lilacs that have become overgrown need to be pruned more aggressively. Two methods are sometimes used: rejuvenation pruning and renewal pruning. In rejuvenation pruning, the lilac is cut down to the ground. It may take several years before the plant is fully back to size. In renewal pruning (which is what you are describing), 1/3 of the plant is pruned out each year for three successive years. Your plant seems like a candidate for a renewal pruning.

Any dead branches can be pruned right now. But I would wait until late next winter to begin the renewal pruning. Then prune out 1/3 of the plant to the ground. Prune out the oldest, largest branches. Repeat this for the next two years.

Read here: