Assessing and managing cold damage in Washington vineyards

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. Vineyard assessment of cold damage can be a laborious process and an unnecessary one if cold damage has not occurred. Prior to making assessments, check local weather data and compare to WSU’s grape cold hardiness data to see if critical temperature thresholds for damage have occurred. If these thresholds have been met, then proceed with damage assessment