I have a Sovereign Coronation purple table grapevine. It is well established. I had grapes on it for the first time last year, and none this year, or any previous years. I have healthy cordons across the trellis. I can't find anyplace to tell me whether I should be cane or spur pruning it. I can't remember what was done the year they produced. I realize I cut too far back this winter and hadn't left any spurs. That is probably what I did the other years too. So: Sovereign Coronation, spur or cane pruned? I have planted a New York Red grapevine as well, and can't find it listed on line to see what way it should be pruned either. Thanks for any help.