when can we trim lilac, so it will come back next year?
Answers:
You must wait till the flowers bloom and die. You then trim off the dead flowers to get it ready for the next year. You can even prune more to shape it the way you want it to grow.
Other answers:
Best to do it when the plant is dormant as with most any tree or plant. Fall or winter would work best
Best to do it when the plant is dormant as with most any tree or plant. Fall or winter would work best
No, lilac flowers from new wood only, the best time to trim it is right after it flowers. This gives the plant time to regenerate before the winter and makes it fuller so you'll get more flowers next year.