I've had my concord grapevine for approx 3-4 years and each year it has produced an abundance of fruit. This year, however, I bet there were 20 grapes total. I tried thinking back to anything that might have changed and the only thing I can come up with is slightly less water was provided to the vine. I altered my downspout and now water flows in a slightly different direction. I have many other plants in the same area that weren't affected. The lack of fruit may have nothing to do with the irrigation change, but that's all I can come up with. Any thoughts?
After doing a little more investigation, I'm wondering if I pruned too heavily last year. Also, I typically prune my vines in late October or early November. Perhaps I should wait until the end of winter before pruning. Any thoughts?
