Pruning lilacs

Asked September 22, 2014, 9:15 AM EDT

I have some overgrown lilacs that need to be cut back. They are presently in full leaf. What is the best time to do this and can you link me to an article or just tell me what to do.

New Haven County Connecticut pruning horticulture flowers: annuals and herbaceous perennials

1 Response

Hi,

Generally lilacs are regenerated by cutting to the ground one third of the largest stems in the spring. There should be some younger, thinner stems left as replacements. Depending on how many younger stems the plant produces, you could remove up to one-third of the older stems for 3 consecutive years. Sometimes for slower growing plants it might take a little longer to fully regenerate the plant. Lilacs like full sun and a soil with a pH about 6.8 or so. After removing some of the older stems be sure to fertilize in the spring and water during dry periods.