Question: After the grapes set their fruit in the next couple of weeks, can the vine be trimmed, or does it need to grow to provide shade and nutrition to the grapes?
As long as your vine is growing vigorously you can continue to prune through the summer. You want to make sure the berries are shaded by the leaves to prevent sunburn.
We trim the vines back several times during the growing season. Usually, table grapes are more vigorous than wine grapes. When the vine is shading itself or out of control, it needs some pruning or thinning of its growth.
Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com.