Évaluation de la rusticité et de la croissance d'arbustes ornementaux à feuillage caduc

The winter hardiness and growth potential of 10 cultivars of deciduous shrubs were evaluated to determine their adaptability to climatic conditions. Plants were grown at eight sites in Quebec and at one site in northeastern Ontario (zones 2, 4 and 5). Cornus alba 'Argenteo-Marginata' and 'Sibirica', Lonicera korolkowii var. Zabelli, Lonicera korolkowii var. morrowii, Lonicera × xylosteoides 'Clavey's Dwarf', Physocarpus opulifolius, Physocarpus opulifolius 'Aureus' and 'Nanus', Salix purpurea 'Nana' and Salix elaeagnos were used. Cornus alba 'Sibirica' and L. × xylosteoides 'Clavey's Dwarf' were not affected by winter conditions at any of the sites, whereas L. korolkowii var. Zabelli and L. morrowii were severely affected, particularly in zone 2. Our results indicated that S. purpurea 'Nana' was more frost resistant than S. elaeagnos. The two cultivars of Physocarpus were slightly less winter hardy than the species. None of the 10 species could be grown commercially in zone 2a. Growth of S. purpurea 'Nana...