Winter Damage Report From Dean Volenberg
University of Wisconsin Extension Agent Dean Volenberg’s “IPM Reports” are always excellent and his most recent report is one of the best assessments of this winter’s effect on Midwestern commercial grape growing.
Dr. Volenberg maintains a vineyard in Sturgeon Bay Wisconsin. In Sturgeon Bay, there were 22 separate days this winter in which the temperature did not get above zero F. Talk about a tough place to grow grapes.
In Volenberg’s bud count data (see link below) please note how well Petite Pearl and the University of Minnesota varieties came through the winter. (Admiral Peary would be very proud of these stoic grapes.)
Volenberg also ventures into Southern Indiana where the polar vortex paid a shorter but still painful visit. He reports that it’s too early to speculate on cordon and trunk damage. However, one can’t help but notice the winter plant damage across the region. As Neil Young said, “It’s a wonder tall trees ain’t laying down.”
I have a limited vineyard with only three lines with grapes, mainly Frontenac. I intend to protect them with a solution of copper sulfate. I received different suggestions focused on its concentration. Please, are you so kind to tell me what about the best way to use it? I bought a bag of 40 lb. from our local farmer co-op, with an indication that is different from a small container I have from a nursery plant shop.