Second year lilac tree/bush was planted and had lots of beautiful flowers. Hubby decided to cut it back in the fall and ever since, no flowers. It is now about 10 years old. Growing like crazy but no flowers. Did he ruin it completely?
Lilacs Won’t Bloom
Certified GKH Gardening Expert
You really want to wait until right after they stop blooming to prune. Pruning in fall will not kill it, but it will greatly decrease the blooms for next year, which sounds like what has happened with yours. For furture reference, this article should help: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
This article will help with additional blooming issues: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm