Lilac trimming in St. Paul

Asked June 21, 2018, 9:14 PM EDT

I have read that lilacs should be trimmed "soon" after they bloom, but "soon" is not defined. I have to cut a large established lilac down to install a fence. It will probably be cut in early July. Given that I am in St Paul, should I expect no blooms the following spring? Also, is there any guidance you can provide about how it should be done in mid-July, given it bloomed in early May? Thank you.

Ramsey County Minnesota

1 Response

By "cut" do you mean head back or remove?

If the plant is cut to the ground, it will not bloom next year. If it is a common lilac, it will bloom again two or three years after that.

If only the largest stems are cut to the ground, any remaining that are old enough will bear flowers next spring.

If the stems are simply shortened (sheared), most, but perhaps not all, of next year's bloom will be lost.