Blooming Lilacs

My great-aunt gave me a cutting of her lilac shrub that blooms profusely. I planted it years ago in our yard and it has yet to produce flowers. How can I get mine to bloom?

—Lori Imgrund, Everett, Pennsylvania

Melinda: Your lilac cutting spent its first few years establishing roots and producing top growth. If it's growing in full sun, it should now be ready to flower. Lilacs in shady areas, however, have fewer or no blossoms and are more susceptible to disease. If it's getting enough sunlight, improper pruning may be the cause of the problem. Lilacs bloom on the previous season's growth, so prune only after it flowers (or when it should have flowered). Pruning at any other time eliminates the flower buds. Also avoid high-nitrogen fertilizers, which stimulate new shoots and stem growth but hinder flowering.