I should have pruned my forsythia in the spring. It is now overgrown and a bit wild. Since it is the end of July, should I wait until the spring blooms fade before pruning or can I prune it back now without harming potential flowering?
Pruning now will affect next spring's blooms. If you look closely at the stems now, you'll see the start of the flower bud. I don't know if your plant has enough time to recover and form new buds. Where I live, plants are in the early stage of changing color. This indicates that plants are transitioning over to the stage of hardening off new growth before winter freeze hits. Of course, you can run your own experiment with a few of the wildest branches.