Have one concord grape vine...when planted did not plan on making wine.. just to use as table grapes... But alas, got into the hobby and I beat the wife to the vine. This will be the second winter for the vine... amazed with the production off of one vine.. 53 clusters... grapes were not huge (size of blueberrys), but I was able to harvest enough to make one gallon. Question is when would be the best time to prune back. Info I have been getting is anywhere from November through February.. Any help would be appreciated.