Arlington Heights, Il
|On a very old lilac tree, I have cut back at various times of the year, all of which never bloomed again. I'm afraid to trim the remaining few towering flowering stalks. When can I cut back these way-too-tall ones and still get blooms next year?
|Answer from NGA
May 7, 2010
|Lilacs grow best in full sunshine and they'll flower best in full sun, too. Lilacs produce flower buds during the summer months which they open the following spring so don't prune your lilacs from mid-summer on so you don't accidentally cut off potential flower buds. Pruning immediately after the flowering period is best and removing no more than one third of the live material on the shrub will help keep it healthy and blooming. If your shrubs need to be pruned back more, you can reduce the size over a 2-3 year period without sacrificing blooms. Prune yours back now (or once the flowers are spent) and they should bloom for you next spring.
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