WCAX.COM Local Vermont News, Weather and Sports-Black rot on grapes

August 18, 2011

Grapes are actually easy to grow in our area and more and more people, especially in the Champlain Valley, are growing lots of grapes for wine and for table grapes. There are some great new varieties that are winter hardy in our region, so you can grow grapes, too!

Grapes do have some problems, and one of those problems is black rot. If you take a look at it, you'll see lesions on the leaves that look like little spots in the spring. If you look at the grapes you'll see some that are all shriveled up. They look like little dried raisins. That's the fungus, black rot, that's causing all of the damage.

What happens is in the spring any of the old rotten grapes that are on the ground release spores. They infect the plant, and when you have wet, humid weather, like we've had this year, it infects the whole plant. You'll see it on the leaves and on the fruit.

So cleaning up anything that is on the ground in fall is the most important thing. Clean up the leaves and all of the fruit on the ground and even the ones that are left hanging on the vines. It's important to do this before next year's bloom season. That will reduce the amount of spores that you have in the area and you won't get as much black rot. Of course if it's a dry season, that will help, too. Fungicides don't really work if you spray this late in the year. It's really just a matter of cleaning everything up and you can grow some great grapes!

Charlie Nardozzi