Kentville Research and Development Centre
2025-26 Bud Hardiness Report No. 1 - Nova Scotia
Attached, from Jeff Franklin and Dr. Harrison Wright, is Nova Scotia bud hardiness report #1 for the 2025-26 year. The Nova Scotia wine grape bud hardiness survey generates occasional reports of the low temperature exotherm (LTE) values over the dormant period (roughly from late October to late April).
Note from the research team: In this first round of the bud hardiness survey for the 2025/26 dormant season, we are seeing that all varieties in the survey are less hardy relative to the same time last year. Typically in early November we would expect to see LTE50 values of -20 °C or lower for hybrid varieties and slightly warmer than -20 °C for vinifera varieties. The difference is most pronounced for L’Acadie, which is approximately 5 °C less hardy than expected. This trend in bud hardiness seems to coincide with the slow rate of lignification seen in vineyards across the growing region and L’Acadie stands out this year as having a considerable amount of green wood present for the time of year. Temperatures in October and November have been approximately 1 °C above the 25-year average, which may be contributing to this delay. Another potential factor is the latent effect of this summer’s drought. Measurements made by our team in Kentville showed that photosynthetic rates were lower through the dry months of the summer than measured in past years. Reduced carbohydrate storage can reduce winter hardiness by delaying wood ripening, lignification and other factors associated with acclimation.