I wait for the forsythia to bloom also. The forsythia are just starting to set leaf buds here. Spring is taking its time this year.
When pruning, I put glue on the larger cut branches to seal the ends. Elmer's white glue or generic dollar store Elmer's works, so does wood glue. This protects the canes from borers. I was told to seal any canes as thick as my pinkie. I had borers in thinner canes, so I seal smaller canes also. If you see signs of borers, cut back the cane past wherever they bored - i.e. cut to the place the cane doesn't have a hole in the center.
I am cutting clearly dead canes now because I am moving the end of this month. Otherwise, I would wait until the forsythia bloomed.
