Freezing injuries account for an estimated 15 % of global grape production losses annually, posing a significant challenge to sustainable viticulture. This study investigated phenotypic variation correlated with cold hardiness in two biparental mapping populations to explore potential markers for selecting cold‐hardy genotypes. Quantitative trait locus (QTL) mapping was also performed to identify loci that could accelerate the development of environmentally resilient grape cultivars. We examined two F₁ families—312 hybrids from V. riparia × V. vinifera ‘Fresno Seedless’ and 302 hybrids from V. amurensis × V. vinifera ‘Valley Pearl’. Differential thermal analysis (DTA) was used to assess bud cold tolerance, and we recorded additional traits including bud water content, trunk and cane diameters, and post–bud‐break phenology. Significant variation was observed in cold hardiness and all measured phenotypes. High‐quality genetic linkage maps were generated for both populations, providing a solid foundation for subsequent QTL analysis and marker development. This research offers a sustainable strategy for breeding cold‐hardy grape cultivars that maintain productivity under harsh conditions and speeds breeding efforts in support of climate‐adaptive viticulture.
