Question: I trimmed our forsythia after it bloomed, and it has since grown approximately one and a half feet. Can I trim the new growth and still get blooms next spring?
Answer: Prune back the stems of forsythias shortly after spring bloom. They begin to grow flower buds during the summer, so pruning them then will probably result in no blooms the following spring. You can prune broken branches anytime. To renovate a severely overgrown forsythia, prune it sharply in the spring. Cut back all the stems to within six inches of the ground to stimulate vigorous new growth from the base. The shrub will recover fully in two to three years.