CHARACTERIZATION OF THE WINTER-HARDINESS OF 7 SPECIES OF ORNAMENTAL SHRUBS BASED ON THE INTENSITY OF WINTER DAMAGE

The winter-hardiness of seven ornamental shrub species was characteriz ed based on their ability to regenerate and to maintain their ornament al characteristics following winter damage. Lonicera involucrata and W eigela hybrida 'Brystol Ruby' reached full ornamental expression in zo ne 5b of the Canadian Climatic Classification System, while Cotoneaste r dammeri 'Skogholm', Hydrangea arborescens 'Annabelle', Kerria japoni ca, Rosa multiflora and Weigela florida 'Variegata' required warmer co nditions. Rosa multiflora and Lonicera involucrata survived in zone 2a , Weigela hybrida 'Brystol Ruby' in zone 2b and the other species in z ones 3 or 4. The partial expression of ornamental characteristics rest ricted the utilization of Lonicera involucrata to zone 2a, of Hydrange a arborescens 'Annabelle' to zone 2b and of Coloneaster dammeri 'Skogh olm' and Weigela hybrida 'Brystol Ruby' to zone 4. Rosa multiflora, We igela florida 'Variegata' and Kerria japonica both received two classi fications based on the expression of different ornamental characterist ics.