“Vine acclimation, or cold hardiness to tolerate winter, is always a concern for growers and the unpredictable and unseasonably warm temperatures have not created the ideal environment to ensure adequate dormancy,” says Matthias Oppenlaender, Chair of the Grape Growers of Ontario. “There was catastrophic damage in the vineyards last winter, particularly in the Niagara Region, causing stress on the vines and affecting the overall grape production.”
Grape growers can check the latest cold hardiness data to determine the critical temperatures for grape cultivars grown in their area. The latest cold hardiness testing shows the most sensitive cultivars (Merlot, Sauvignon Blanc, Syrah) may sustain some freeze damage when temperatures drop below -18°C. Most LTE10 values are in the range of -19 to -22°C. Bud survival assessments will be done over the upcoming weeks to determine any impact of this weather on primary bud survival.
Grape Growers of Ontario CEO, Debbie Zimmerman, said “The continuous fluctuations in weather are troubling. Growers have access to bud hardiness information as a tool to assist with establishing the optimal use of wind machines in vineyards that have them, which can reduce the overall injury to the vines. Extreme weather events of 2022 reduced our crop by 50%, and we are very concerned about the upcoming weather predictions."