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W i n e s & V i n e s J U LY 2 0 1 4 77 S ilent spring. That was what some grapegrowers experienced this May, when buds should have been bursting with rapid shoot growth. Instead many east- ern farmers saw more widespread evidence of winter cold injury than they expected based on estimates made earlier this year. Typical bud injury was evident, but so was injury to trunks and cordons, which spanned a surprising range of varieties. The 2013-14 winter will be remembered as a cold, changeable and persistent sea- son. On the whole, the low temperatures experienced throughout Virginia were not that low. Many locations reported lows in the 0° to -3° F range, while a few dipped as low as -7° F. Reports of injury started rolling in follow- ing the early January dip in temperature, when a low of -2° F was recorded at the Agricultural Research and Extension Center (AREC) vineyard in Winchester, Va. The vines at the AREC appeared to come through that event unscathed. Reports of damage to cold-tender vines including Tan- nat and Merlot arrived soon after. Critical temperatures appeared to be at or below about -4° F. There were at least five oscillations in air temperature between early January and early March, with the event on March 4 following a three-day stretch of highs close to 60° F. One grower said that the injury at his vineyard during this most recent winter was reminiscent of what he observed a decade earlier, following the 2003-04 winter season. I went back and read what I had observed following the 2003-04 winter in "Viticulture Notes," a newsletter I write for the Virginia Cooperative Extension, and was struck by WineEast Virginia's 'Silent Spring' What growers can do to recover from cold injury reminiscent of 2004 By Tony Wolf Wine East HIGHLIGHTS • Virginia growers are seeing more wide- spread evidence of winter cold injury than estimated earlier this year. • The article compares the weather condi- tions and damage in 2013-14 with similar experiences in 2003-04. • Avoiding nitrogen fertilization and allow- ing up to five or six shoots are among the ways to get damaged vines healthy again and back into production. Excerpted from 'Viticulture Notes' newsletter from May 2004 I commented in the January-February "Viticulture Notes" (2004) that the 2003-04 winter was shaping up to be a winter that would cause minimal cold injury to grapevines here in Virginia. Reports and my own observations since February have led me to reassess that statement. In reality, a number of Virginia vineyards are now showing evidence of cold injury. Affected vineyards span a wide geographic area. Those that I'm aware of range from Loudoun County south to Roanoke, and vineyards in Frederick and Shenandoah counties. The injury includes typical bud and cane injury as well as injury to older wood—cordons and trunks. In many cases, the latter has included significant crack- ing or splitting of older cordons and trunks. It was often the trunk splitting that caught growers' attention. The extent and nature of the observed injury is somewhat puzzling. The low temperatures measured or estimated from nearby minimum/ maximum thermometers during the 2003-04 winter were generally at or above 0° F, with the lowest temperatures occurring around Jan. 10. Given the general pattern of winter temperatures—not a great deal of fluctuation in mid-winter—and our own measures of bud cold-hardiness (reported in January-February "Viticulture Notes"), I would not have expected much problem with temperatures at or above 0° F in January (at least not with generally well-managed vines in normal years). In some of the affected vineyards, varieties that we recognize as relatively cold tender were the most severely affected. For example, (Continued on page 78.) High (red) and low (blue) temperatures are plotted at the Agricultural Research and Extension Center in Winchester, Va., during the 2013-14 winter dormant season. Daily high and low temperatures (º F) October November December January February March April 2013 2013 2013 2014 2014 2014 2014 90 80 70 60 50 40 30 20 10 0 -10 Temperature Extremes During Winter 2013-14