I have two forsythia bushes that didn't need trimming after they bloomed, so I didn't do it. But now, they're out of control since we had a lot of rain and I want to know if I can trim some of these very overgrown branches. I am afraid if I do, they will never bloom again. I live in Zone 5.
Trimming Forsythia Bushes
Certified GKH Gardening Expert
Pruning is usually limited to spring after flowering; however, a light trim in the fall will not harm the shrub. It will simply inhibit the flowering of next season's blooms. Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/shrubs/forsythia/forsythia-pruning.htm