C. Richerleclerc et al., EVALUATION OF THE HARDINESS AND GROWTH OF DECIDUOUS ORNAMENTAL SHRUBS, Canadian Journal of Plant Science, 74(3), 1994, pp. 615-622
The winter hardiness and growth potential of 10 cultivars of deciduous
shrubs were evaluated to determine their adaptability to climatic con
ditions. Plants were grown at eight sites in Quebec and at one site in
northeastern Ontario (zones 2, 4 and 5). Cornus alba 'Argenteo-Margin
ata' and 'Sibirica', Lonicera korolkowii var. Zabelli, Lonicera korolk
owii var. morrowii, Lonicera x xylosleoides 'Clavey's Dwarf', Physocar
pus opulifolius, Physocarpus opulifolius 'Aureus' and 'Nanus', Salix p
urpurea 'Nana' and Salix elaeagnos were used. Cornus allan 'Sibirica'
and L. x xylosteoides 'Clavey's Dwarf' were not affected by winter con
ditions at any of the sites I 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. el
aeagnos. The two cultivars of Physocarpus were slightly less winter ha
rdy than the species. None of the 10 species could be grown commercial
ly in zone 2a. Growth of S. purpurea 'Nana', S. elaeagnos and P. opuli
folius 'Aureus' was limited in zones 4b and 5. The hardiness zones of
the 10 species were made more precise, established or modified.