Lancaster, Pa.—Grapegrowers east of the Rockies often face cold winters. January 2014 reinforced that understanding, as temperatures Jan. 6-8 dropped to lows not experienced for two decades across the Midwest and into the East. Those low temperatures, accompanied by strong winds, came from a large pocket of very cold air known as a polar vortex, which normally sits over the polar region.

The Finger Lakes region in New York, home to approximately 11,000 acres of grapes, experienced low temperatures between -3° and -11°F on the east side of Lake Seneca. Overall, New York has 350 wineries and 37,000 acres of grapes. In Pennsylvania, low temperatures ranged from -1° F in Lancaster County to -10° F in Tioga County in the north-central part of Pennsylvania; the state has a total of 13,600 acres of vineyard and 172 wineries. The low temperatures in Ohio varied from -6°F in the southeast to -16°F in the northwest; the state has 1,900 acres of grapes and 144 wineries

Dr. Imed Dami of Ohio State University reported that temperatures in Ohio had dipped as low as -24°F in 2009. “The 2014 cold, however, was different in a bad way,” he reported. “It was an advective freezing event, meaning a massive cold air front moved to our region with windy conditions. To make matters worse, the lowest temperatures lingered for hours.” In addition, Dami thinks the vines were not as cold hardy because of mild weather in December and fluctuating temperatures prior to the temperature lows Jan. 6-7.

According to Dr. Murli Dharmadikari at Iowa State University, growers plant vineyards with cold-hardy University of Minnesota-propagated hybrids in Iowa, Minnesota and North and South Dakota.

Mark Chien at Pennsylvania State University suggested that growers wait before cutting buds to determine the extent of the cold damage and then make pruning adjustments.