Grapes are turning brown and not ripening

Asked June 29, 2017, 9:10 PM EDT

My Grapes are a disaster. The grapes formed in abundance, but once they neared full size, they are turning brown and not ripening. What is going on. The Valiant Vine is the problem. The vine of Concord Grapes are not showing any sign of the blight. Any idea how I can help them?

Ramsey County Minnesota

5 Responses

It appears as though your Grape may have black rot, a fungus that affects grape vines. In the picture you sent there are small circular discoloring on the leaves with a darker circle around it. The best control is cultural, picking up the infected fruit and leaves and disposing of in trash. Below is a link with more information regarding black rot.

Thank you so much. That is what it is. I will clean the mummies this fall and hope this won't reoccur.

we have a 2nd huge problem. A green/black beatle infestation. They are decimating mybgrape vine and linden treee next door. Any suggestion for the vine or tree?

You have Japanese Beetles. They especially grape, Linden and rose leaves. Your best defense is to hand drop them into a bucket of soapy water. Below is a link to information on their life cycle and eradication.

I have tried the cultural remedy and pick up the mummies and clean the vine, and it helped to reduce the blackrot, but the outbreak last summer was still pretty severe - half the grapes were impacted, but not all the grapes like the summer before.

I would like to spray a fungicide now this spring on my backyard vine. One is a Valient Grape and one is a concord grape. Is there a specific recommendation for what to spray?

Below is a link that details Black Rot in grapes, cultural and chemical control. When using chemical control make sure grapes is listed on the label of the fungicide you purchase. Additionally, always mix and use the chemical as per label instructions.