The flavor of my 'seedless' concord grapes varies from year to year from unusable to great rich robust concord flavor and aroma. This year we harvested 200 pounds of nice looking grapes which only had a hint of concord aroma. They tasted sweet when eaten, but the juice is tangy, not sweet. How can I get consistantly good result from my grape vines (barring bad weather)? Will green table grapes growing near interfere with the quality of my concords? I have read that grapes don't cross-pollinate, but when I cut the green grapes down before they blossom the concords are much better flavored. Harvesting and juicing are too much work to be wasted on a poor quality crop. I have had great juice from these same vines, but not consistantly. Help!
The Concord Seedless is a "sport" or mutation of the standard Concord grape, as opposed to a bred variety, bred and selected for specific characteristics. As such, (though it has been "refined" by selection) it's pretty much "what you see is what you get", and one of it's known weaknesses is variable production. If your primary use for the grapes is juice, then you don't need the seedless variety. Why not try grafting or budding at least some of your vines to regular Concord? You may see some disparaging remarks about Concord, and I'll admit it's not one of my favorites, but it's a strong and proven variety, and suitable for your location (US zone 5b?). The cross pollination should not be an issue. If you are cutting them down before they bloom, dig them up and plant some good strong 1 or 2 year vines in their place. Ralph
Doesn't the summer have alot to do with it too? A warm summer would make for sweeter grapes. Unfortunately there's nothing you could do about that. Maybe not watering as much would make the crop smaller but sweeter. If you research about growing grapes for wine I bet this is a wealth of information about this subject.
