Cold Hardiness Estimates of Woody Taxa From Cultivated and Wild Collections

Abstract

Abstract Twenty woody taxa from cultivated and wild collections were laboratory tested for midwinter and/or late winter cold hardiness using leaf and/or stem tissue. Potential introductions from Acer rubrum, Cedrus libani, Gardenia jasminoides, and Osmanthus americanus were more cold hardy than their species zone ratings. ‘Alice’ and ‘Alison’ oakleaf hydrangea, Hydrangea quercifolia, and three clones of Osmanthus americanus, although similar in ornamental characteristics, showed large differences in cold hardiness. Clones of Cornus florida and C. mas from Spring Grove, Cincinnati, Ohio, were cold hardy to at least−30°C (−22°F) in January. Wild-collected Camellia japonica, Staphylea bumalda and Styrax obassia from Korea were at least one zone hardier than typical for the species.