This has been a cold winter, but have you ever wondered what effect the winter weather has on your next bottle of wine? There was a great article recently in The Washington Post discussing grapevines and cold temps.
According to the article by David McIntyre
" While we spent last month shivering and complaining about the polar vortex, local vintners were nervously checking their thermometers as record low temperatures threatened to damage their vines.
Grapevines are dormant this season, but they are not immune to the vagaries of winter. Sustained low temperatures can damage the buds that eventually will carry this year’s crop, and sudden, severe temperature drops can even kill the vines. Vintners won’t know the winter’s true effects until the growing season starts in spring, but there have been reports of extensive damage to vineyards in Ohio and Michigan. Cornell University reported bud damage in New York’s Finger Lakes, especially to Riesling and merlot vines around the northern end of Seneca Lake.
“When temperatures get to the single digits, grape growers tend to get concerned,” says Doug Fabbioli, owner and winegrower at Fabbioli Cellars in Virginia’s Loudoun County. “Each varietal has its winter damage temperature. On the higher number would be merlot at 0 degrees, meaning that it’s more sensitive than cabernet franc at minus 10.” The windchill factor magnifies winter’s effects on humans but not on vines.
Healthy vines are a vineyard’s best defense, Fabbioli said. Vines contain stored energy in the form of sugars from photosynthesis during the past year’s growing season, and the sugars act as a sort of antifreeze during harsh winters."
Tony Wolf is our local expert at the Virginia Coooperative Extension. He sent out a recent "Viticultural Notes" bulletin discussing the temperature issues. He states that the vines should be fine for the most part, but there may be isolated areas of damage.
We are hovering just above the critical temperatures for winter vine damage. In fact, it is a bigger
worry to vineyards when we have cold temperatures in the spring.
According to an article in Winemaker Magazine:
"Frost damage happens when temperatures drop below 32 °F (0 °C) after green growing tissue has appeared from a bud. It is generally a threat early in the growing season on cold clear nights, shortly after budbreak. It is such a danger because the first green growth produced on a new grapevine shoot is two or three basal leaves, immediately followed by the embryonic flower clusters that will become this year’s crop. So, if frost strikes, it can greatly reduce or even wipe out the whole vintage. "