My lilac is 6 years old. It has never bloomed. It is planted in a garden where it receives full sun, is not surrounded by other plants, has never been pruned, and otherwise looks healthy. What kind of soil is needed? It does not get fertilized and all other plants in the garden are lush and healthy (and bloom!).
Why Won’t My Lilac Bush Bloom?
Certified GKH Gardening Expert
I have read that it can take up to 6-7 years for some lilac varieties to start blooming.
This article discusses the many reasons for non-blooming lilacs: