During the winter, grapevine varieties require some degree and duration of low temperature exposure in order to fulfill plant chilling requirements. Adequate chilling is critical to uniform and timely budbreak the following spring. However, in northern production areas, vines can be exposed to very low temperatures, or sudden drops in temperature that are outside of their range of adaptation. When temperatures fall below the level of vine cold hardiness, there can be damage to buds, canes, cordons, trunks, or roots, and even death of the vine. In addition to sudden temperature drops below cold hardiness thresholds, prolonged low temperature durations that are above these thresholds can often result in cold-related damage symptoms on the vine. The damage from this type of cold exposure is a result of tissue dehydration. For further detail regarding the definition and identification of grapevine terms used here, please see WSU publication EB2018E, entitled “Canopy Management for Pacific Northwest Vineyards.”
