and, therefore there is accumulation of dead branches above pergola which is approximately 16 feet long ... I was wondering how severe can I trim these back to get rid of the dead stuff?
Properly pruned grapes have over 90% of their new growth removed every year. They can be cut back almost to the ground and still come back vigorously, although they wouldn't produce much, if anything, until the second year.
Thank you, kindly, for your response. I will trim them right back. And, I am not concerned with grape production because the raccoons get to them before we do.
