The forsythia bush hasn't bloomed in the last two years. I prune it after it has bloomed, but maybe I'm waiting too long after it's done blooming, usually a month or more.
How Do I Get My Forsythia Bush to Bloom?
Certified GKH Gardening Expert
This article will help you determine the cause:
The best time for trimming forsythia is in the spring as soon as possible after the blooms fade. Forsythia sets flower buds in late summer on the growth it puts on during that years growing season. Hence, blooms are created on one year old wood.
For more information on how to prune forsythias, please visit the following link: