Since 2009 we have been testing grape buds at the lab for sensitivity to winter cold using a “Differential Thermal Analyzer”. These data have given us a prediction of bud mortality so that the severity of spring pruning can be estimated depending on bud mortality. With funding from Viticulture Consortium-East, the Lake Erie Regional Grape Program, Inc., and the New York Wine and Grape Foundation, we are posting bud cold hardiness information for representative varieties in New York, measured at commercial and Cornell vineyards in the Lake Erie, Finger Lakes, and Hudson Valley regions.
We have chosen Riesling, Cabernet Franc, Pinot noir, Seyval, and Concord as representative varieties exhibiting a broad range of bud hardiness under NY conditions. Vineyards are sampled every two weeks from December 1 through March. Most recent LT50 (Median Bud Freezing Temperature) values for each region are listed in separate tables on the Cornell’s grapes and wine website. Clicking on a variety name will bring up individual graphs of minimum/maximum temperatures and seasonal change in bud freezing temperatures.