Hi Jessica, I planted your basic lilac bushes about 3 years ago when I purchased my house. The first year the bushes bloomed fully and that was it. The past few years I haven't been so lucky. I do give them fertilizer each spring. Is there something I'm doing wrong? Should I prune them down? If so what do I use and when do I prune? Also they get partial sun/shade. Thank you! -- Kerrie Huser, Mount Sinai
The problem could be one of two things. Lilacs need full sun in order to bloom to their full potential, so your partial shade conditions could be to blame. Also, applying too much nitrogen fertilizer will force the plants to put most of their energy into growing in size, leaving little for blooming. I would skip the fertilizer this year and see what happens. If it still doesn't bloom properly, you'll have to trim nearby trees and/or shrubs to open the plant up to more sunlight, or if that isn't possible, move it. Good luck!