by David Benzing, Ph.D.
David is Co-founder of Vermilion Valley Vineyards and one of its Winegrowers. A retired professor of biology and environmental science at Oberlin College, David is the author of numerous books and reports on the adaptive biology and evolution of epiphytic plants.
The 2015 vintage: a summary
The fact that northern Ohio endured temperatures as low and occasionally even lower than the lowest delivered by the widely reported 2013-4 “polar vortex” was largely ignored by our local news media. Worse yet no mention at all was made of the severe damage inflicted on the state’s vinifera-type grape vines and whether this setback threatens the development of the state’s premium wine industry. In no way does the adage “old news is no news” excuse such a lapse considering that now it’s not just once but twice and in two successive years that extreme cold killed almost every exposed trunk and cane. Nothing comparable has occurred since at least the mid 1970’s, and nothing like it was expected given the increasingly mild winters predicted by climate modelers. But let’s leave the subject of future prospects for now and move on to how VVV fared in the face of a record-setting, double-barreled, weather-driven catastrophe and what happened during the following growing season.
Much to our dismay last year’s punishing winter weather was followed by multiple additional misfortunes. First off a frosty night in late May destroyed many expanding shoots, and June through mid July brought enough precipitation to allow water logged soils to cause leaves to fade from bright green to yellowish through much of the lowest lying parts of our three vineyards. Then an early arriving infection by downy mildew forced a near doubling of the usual number of spray applications. The greatly welcomed reprieve, when it finally arrived, was abrupt almost as if someone had flipped a switch! Clearing skies brought exceptionally favorable conditions that continued through most of the rest of the growing season. Some powdery mildew showed up in mid August along with more than the usual number of hungry birds. On a positive note, September passed without the anticipated and much dreaded invasion by waves of stinky, multicolored, Asian ladybugs.
Despite the problems described above, VVV managed to harvest enough grapes to produce about 1000 gallons of wine, the two most bountiful varieties being respectively Chambourcin and Riesling at about 225 and 275 gallons apiece. Full crops from all 15 would have added up to something around 6-7000 gallons—about 15% of vineyard capacity. At this point let’s shift topics a second time just in case you wonder how a significant harvest was possible in fall 2015 when the polar vortex that caused just as much vine injury the year before left us almost nothing to pick. The short answer is simple: it’s the way grape vines grow rather than the weather they experience that determined why our vineyards yielded 1000 gallons of juice in 2015 compared to a mere pittance the previous season.
A properly trained grape vine produces all of its fruit on trellis wires, and any shoots that develop farther below are removed unless needed to replace injured or dead trunks. Should a freeze-vulnerable type such as a Chardonnay or Riesling vine whose base is insulated by mounded soil experience lethal winter conditions the following spring will see it respond by generating numerous canes along the surviving few centimeters of trunk located just above the graft union (see the Cabernet franc vine illustrated in the blog entry preceding this one). Although generally robust fruiting by these “adventitious” shoots or “suckers” is typically sparse or less. On the other hand, should one severe winter’s impact be repeated the next year the twice affected vine will respond by producing fruitful lateral shoots from the surviving (because they were buried) basal portions of those shoots produced (and not pruned) the previous year. The Riesling vine pictured here just prior to harvest illustrates this pattern.
If nature decides to give Ohio’s premium wine growers a break in 2016 it will come as a typical or milder winter followed by a spring without killing frosts. Prospects in mid December look about as good as they can at this point in the seasonal cycle. Temperatures have been unseasonably warm perhaps due to the effects of what meteorologists predict will be an unusually powerful El Niño event, a recurring (every few years) tropical Pacific Ocean phenomenon whose influences extend for many months into much of the northern hemisphere. Our part of North America usually experiences higher than average winter temperatures during El Niño events: snowfall is less predictable. With luck El Niño’s influence in northern Ohio will persist at least into March allowing us at VVV to start rebuilding our vines a second time and to look forward to a larger crop in 2016 and even better times after that.
Have any questions or comments for David? Please email him at: firstname.lastname@example.org