Question: How do I prune my grapes once they’re established?
Answer: In a word, heavily. You’ll probably remove 80 to 85 percent of the cane growth off each vine each winter. From all of the upright cordons you’ll want to select 15 to 20 that are 4 to 6 inches apart on the lateral branches. Prune all of these cordon stems back to two buds each. The next year’s fruiting cordons will originate from each of these buds. Their vigor will determine how much you prune the plant the following winter. Vigorous vines can be left somewhat longer, while those that grow less vigorously should be pruned more heavily, leaving fewer buds. In general, however, you’ll always end up with the main stem and its two 4-foot lateral branches, and 15 to 20 cordon spurs and their two buds per spur. Repeat this process each winter as long as you have the grapes. If all of this is too confusing, gardening references often show illustrations, as do pages on the Texas A&M Horticulture Department’s website.