How To Identify The Difference Between Suckers And Growth.

Question

In trying to renew an old lilac, I have gradually over several years cut back the top heavy old branches. New growth is popping out all over the garden. Which are suckers and which are okay to keep?

Answer 1

To prune after blooming, remove 1/3 of the oldest and widest canes each year by cutting them to the ground. Do this over a period of years to rejuvenate the plant. New growth will grow from the base, replacing the older canes. If you are getting new growth (suckers) coming out of the main trunk, remove those.

https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm