Lilac Bush Full of Buds but Never Blooms

Question

We have a very large, old lilac bush. It was full of blooms 3 years ago, then we pruned it. Since then, it has been full of buds each year but it fails to bloom. The buds never open. Can you tell me what the possible problem may be?

Answer 1

This article may help: https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm