Grapes ripening unevenly

Asked September 7, 2019, 1:16 PM EDT

Grapes seem to be ripening earlier this year than in years past. I am noticing that some of the grapes on the cluster are already wizening up when there are some still green? I don't know why this is happening, and whereas it's too late to rectify this year, what I might do differently next year. They have had the same amount of water they always receive; and I have not sprayed them in years past with any kind of fungicide. Thanks, Sherrie Wieland

Douglas County Oregon grapes horticulture

2 Responses

Uneven ripening can be caused by a couple of things. Usually it is caused by uneven pollination which happens in years where rain fell around the time of flowering. That is the most common reason. The other thing that causes uneven ripening is viral disease. When a vine gets a virus invading it can mess up the ability of the vine to ripen grapes properly. If the grapes that are full sized in the cluster are ripening ok and taste sweet, your clusters had a problem with pollination. If the large grapes don't seem to ripen well and get sweet, then it is probably a virus.

Thanks so much for the quick answer. The grapes are sweet so I think it was the pollination issue.