Q: When is the best time to trim a Spirea shrub?

A: It depends on what your goal is.

If you have an overgrown spirea, the ideal time to prune it heavily is in late winter, just before spring's growing season. This way, you can prune it very dramatically and have less time to wait for new growth to fill it in.

You will lose many or most of the flowers for that year, but if the plant's overgrown, you probably have a greater need to get the shrub back in shape than enjoying its flowers for that given year.

If you have a spirea that just needs to be maintained, the best time is immediately after it's through flowering.

This will allow the plant time to set flower buds for the following spring.