Four Days of Cold Temperatures Devastate Upper Midwest Vineyards
June 12, 2019
|Map of wind chill temperatures on January 30, 2019 from the National Weather Service, National Oceanic and Atmospheric Administration.
|Dead vines in grower Bob Neal’s vineyard in Alexandria, MN. Photo credit: Bob Neal
On Friday, June 7, friends of Famous Fossil Vineyard and Winery in Freeport, IL received a letter from the winery’s owners, Ken and Pam Rosmann, that stated: “Many of you have noticed the lack of growth on our grapevines. Unfortunately, the damage from a wet fall, a very cold winter and a late spring have meant that 90% of our vines have died.”
If you talked with any grape growers or vineyard managers this spring, from Texas to Georgia, or north to Connecticut and west to Indiana, there was one word to describe the weather – wet, just as the Rosmanns said in their letter. Rain ended the drought of last year in Texas, flooded the rivers in Missouri, and delayed spraying in vineyards in the Finger Lakes of New York and many other places east of the Rockies. Spring weather was late in arriving and the rainy days were frequent until late in May.
In most regions east of the Rockies, many growers described the past winter as relatively mild, although there were some snowy days and icy roads. It was not like the winter of 2013-2014 when the infamous Polar Vortex delivered very cold temperatures across the East and Midwest multiple times from December through March. The following winter was also unusually cold, with temperatures dropping below zero from Virginia to New England and across the Midwest.
The winter of 2019 was different. According to Mike White, extension and outreach viticulture specialist at Iowa State University, the upper Midwest was hit with four days of extremely cold temperatures in late January. Iowa had low temperatures around -34° F, while Minnesota and Wisconsin had lows around -40° F. The wind chill low temperatures may have been even more important than the very low temperatures. For example, Alexandria, MN reached a low temperature of -31° F on January 29; on the same day the wind chill dropped to -63° F. In April and May, warmer spring temperatures were slow to arrive, and many growers didn’t realize until after bud break the extent of the damage done to their vineyards from January 27 to 31.
Iowa, Minnesota, and Wisconsin, as well as northern Illinois and eastern North and South Dakota had low temperatures not experienced since 1996 and wind chills not seen since the 1980s. This spring, White has seen vineyards in Iowa where only tertiary buds are pushing, cordons are dead, and in some places the trunks are dead. “In Wisconsin and Minnesota, it’s a disaster,” White said.
Vineyard damage in Minnesota
Annie Klodd, assistant extension professor for fruit and vegetable production at the University of Minnesota Extension, told Wine Business Monthly, “A lot of vineyards in Minnesota got down to -40° F. Even southern Minnesota had really cold temperatures. Some growers lost vines down to the ground, but that’s not the case for everybody. You can see two vineyards; in one, most shoots are alive. Twenty miles away, the Edelweiss and St. Pepin will be dead to the ground.”
Klodd thinks that mature vines that weathered the Polar Vortex in 2013-2014 are still dealing with the vascular disease they incurred during that winter. She also is concerned that vines with trunk disease may be less able to withstand cold temperatures.
“It’s been a depressing couple of weeks,” Klodd stated. “Some vineyards with substantially lower crop yields will have to find grapes from elsewhere. Beginning growers with a small vineyard, just a few acres, should check with wineries before they plant vines and find out what varieties they want. And in colder areas, they should go with easier to grow varieties.”
Many growers are seeing between 2 and 15 suckers coming up from the base of the vine according to Klodd. She encourages those growers to leave extra suckers this year, approximately five suckers on a vine, then train a couple of them up to become trunks next year, while keeping a few more to suck up the energy from the root system in order to discourage the growth of bull canes.
Some cold climate varieties fared better than others under the stress of very cold temperatures. La Crescent, Frontenac and especially Itasca did quite well, whereas St. Pepin and Edelweiss suffered more damage. Marquette, which is not known for extreme cold tolerance, also did better in some locations than others.
Spring frosts in Wisconsin
Céline Coquard Lenerz, third generation of the Wollersheim family at the Wollersheim Winery in Prairie du Sac, WI, reported that the lowest temperature in their vineyards was -30° F. She did a bud count in February after the deep freeze in late January and determined that the vineyards had lost about 50% of their primary buds, which is higher than usual.
The cold damage done by the extreme temperatures in January was compounded in the Wollersheim vineyards by a spring frost on April 27-28 when temperatures dropped to 27.3° F. “The primary bud loss is about 60% in the reds,” Lenerz stated. “The whites are slower to push, and their bud counts look more normal. We may have to do some replanting, but more will need re-trunking. Lots of growers are seeing the same thing, and we will get some crop from secondaries.”
The good news: this past week nice weather, with sunshine and warmer temperatures, finally arrived in Wisconsin and other parts in the upper Midwest.
|Suckers coming up from the base of a dead trunk. [Photo credit: Annie Klodd]
|Cannon Valley Vineyard in Cannon Falls, MN, owned by Lisa Smiley, went to a low temperature of -34° F in January, but suffered little damage in the winter of 2019. On June 1, 2019 the vineyard was fully leafed out. [Photo credit: Annie Klodd]