Cold hardiness of landscape pear taxa

• Published in: Journal of environmental horticulture 1994-12, Vol.12 (4), p.227-230
• Main Authors: McNamara, S. (University of Minnesota Landscape Arboretum, Chanhassen, MN.), Pellett, H
• Format: Article
• Language: English
• Subjects: ACCLIMATIZATION; ADAPTACION; ADAPTATION; COLD; FRIO; FROID; hardiness zones; ORNAMENTAL WOODY PLANTS; PLANT CONTAINERS; PLANTAS LENOSAS ORNAMENTALES; PLANTE ORNEMENTALE LIGNEUSE; PYRUS; PYRUS CALLERYANA; pyrus fauriei; PYRUS SALICIFOLIA; PYRUS USSURIENSIS; RECIPIENT DE CULTURE; RECIPIENTE DE CULTIVO; RESISTANCE A L'HIVER; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; RESISTENCIA INVERNAL; TEMPERATURE RESISTANCE; WINTER HARDINESS
• ISSN: 0738-2898; 2573-5586
• DOI: 10.24266/0738-2898-12.4.227

The cold hardiness of ten landscape pear cultivars and two pear species was evaluated in container- and field-grown plants during the dormant periods of 1991 through 1994. Timing and extent of acclimation by containerized plants overwintered in a temperature-moderated greenhouse was similar to that of plants growing in the field, indicating that containerized stock can be used for determining the hardiness of taxa lacking sufficient hardiness to survive outdoors in USDA Zone 4a. Among P. calleryana cultivars, ‘Autumn Blaze’ exhibited the best overall cold tolerance and greatest mid-winter hardiness [−34°C (−29°F)]. ‘Bradford’ was consistently the least hardy P. calleryana cultivar. All P. calleryana cultivars acclimated too slowly in the fall and or lacked sufficient mid-winter to survive in USDA Hardiness Zone 4a. Both P. salicifolia ‘Silver Frost’ and P. fauriei were hardier than the P. Calleryana cultivars on most sampling dates. P. ussuriensis was the hardiest taxon on all sampling dates and withstood −42°C (−44°F) by mid-December 1992. In field trials, only ‘Silver Frost’, P. fauriei, and P. ussuriensis survived exposure to −36°C (−32°F) in January of 1994.