An abnormally warm winter mixed with Missouri's fluctuating weather leave winery owners fearful for late spring frosts.
Seven Springs Winery
Cold snaps worry Mid-Missouri winery owners
By Emil Lippe, Sierra Morris, Rachel Thomas, Jiayi Wang
Cory Bomgaars looks across the barren vineyards of Les Bourgeois Winery, hoping the mild temperature in February would stay the same. Cold weather after warm weather is harsh for the wine industry. In 2007, Les Bourgeois Winery in Rocheport expected to have a normal yield of grapes in their vineyard until sudden cold snaps after a long period of warm weather in the spring resulted in a huge loss in their total grape yield.
“I mean we typically process about 1,600 tons of grapes,” said Cory Bomgaars, Vice President of Winery Operation at Les Bourgeois. “I think that year we processed about 250 to 300 tons.”
This February has seen such warm temperatures that grape plants are coming out of dormancy early. In addition to warmer weather, rainfall results in grapevines budding prematurely, causing them to sap. When these cold snaps occur along with rainfall, the sap freezes, killing the grapevines and resulting in significant losses in grape yields.
This type of weather nearly wiped out the Les Bourgeois’ 2007 harvest.
This year, Bomgaars expects the grapes to bud prematurely again during the month of March.
Once the vines have begun to bud prematurely, it's in the best interest of the farmers for the warm weather to stay. The temperature makes the biggest difference in the yield of grapes.
“Having a frost event or having a lower crop doesn’t necessarily make it a bad year on quality, it just makes it a less profitable year,” Bomgaars said.
According to Mike Bleile, owner of Seven Springs Wineries, grape farmers typically make about 1000 dollars per ton of grapes. In terms of yield, more than 25 tons leads to a profitable year for Bleile’s winery, a yield of 16 tons and the winery breaks even, anything fewer results in a net profit of zero. In 2007, Bleile was facing heavy losses as a result of frigid cold snaps.
“How far the temperature drops is important because different varieties respond differently,” according to Gregory Jones, Professor of Environmental Science and Policy at Southern Oregon University.
To predict their crop yield, grape farmers pay close attention to freezing temperatures and the duration of the colder climate. A difference in only a couple of degrees can have drastic effects on grape plants.
Mike Bleile, owner of Seven Springs Winery in Linn City, Missouri said monitoring the temperature is a top priority around March and April.
“With it being warm like this and the cold snap coming up it’s got everybody nervous,” Bleile said.
During the most recent cold snap that Seven Springs experienced back in 2012, Bleile was only able to harvest five tons of grapes as opposed to his usual harvest of 25 tons. Since Bleile had already invested in the process of fertilizing and harvesting, he was facing a heavy loss for the year.
“Other years, you’re better,” Bleile said, “It’s kind of like farming anything, weather affects it and your yields.”
Unfortunately for many farmers, the solution to cold snaps is not easily identified.
Laszlo Kovacs, an adjunct professor in the division of plant sciences at the University of Missouri said, “you can transfer it by crossing, making a hybrid between the cultivated grape and that [other] grape so they'll be able to make cold-tolerant grapes.”
Breeding programs are a possibility, but they are uncommon in North America. Canada along with states such as Minnesota and Arkansas have established breeding programs for grapes. Grapes in these states are bred to withstand colder temperatures in the winter.
Another plausible solution for making the vines more susceptible to the colder temperatures is grafting.
According to Kovacs, grafting is the process of forcing “two plants to live together, so what you do is you take out the root system of one plant, then you cut it in such a way that you insert a piece of stem into that, and that stem that you insert has buds on it.”
In states with bigger wine industries such as California, some wineries are able to afford ventilators.
“They produce very expensive wine so they can afford to install, for example, those big propellers to mix the air if it gets too cold,” Kovacs said.
But wineries in Mid-Missouri don’t have these resources at their disposal.
“You’re kind of at mother nature’s mercy so to say,” Bleile said.
But these types of extreme fluctuations in weather during the harvesting season are uncommon. For grape farmers like Bomgaars and Bleile, their annual success relies on the calming of Missouri’s climate.