Stem and Leaf Hardiness of 12 Abelia Taxa

Twelve taxa of Abelia were evaluated using laboratory procedures to determine maximum stem and leaf hardiness and to evaluate timing of acclimation and deacclimation over a two-year period. Among the 12 Abelia taxa evaluated, ‘John Creech’ was among the hardiest taxa for both stems and leaves on the majority of test dates. Stems and leaves of ‘John Creech’ survived to at least −26C (−15F) and −21C (−6F), respectively, in January 2001. ‘Edward Goucher’ and ‘Confetti’ had the least hardy stems and leaves, respectively. Stems of ‘Edward Goucher’ survived to at least −16C (3F) in January 2000, and ‘Confetti’ leaves survived to only −14C (7F) in December 2000. Abelia × grandiflora consistently ranked among the first to attain cold hardiness in the fall and among the last to lose cold hardiness in the spring in both test seasons. Stems were equal in hardiness or hardier than leaves on the majority of test dates in both test seasons. Laboratory results were consistent with field observations, but often differed from published hardiness ratings. Differences in lowest survival temperatures and attainment and retention of cold hardiness closely followed temperature fluctuations just prior to sampling dates.