Two of six selections of Chinese evergreen oak (Quercus myrsinifolia Blume) were identified through laboratory cold hardiness estimations to possess more spring cold hardiness potential than the other selections tested. The leaves and stems of all selections had similar cold hardiness levels in the fall and midwinter. Data collected over two winter seasons revealed that leaves reached a cold hardiness level of − 15 to − 18°C (5 to 0°F) during the midwinter. The stems were slightly less cold hardy than the leaves and attained a cold hardiness level of − 12 to − 15°C (10 to 5°F). In the spring, however, the cold hardiness levels of the leaves of two of the selections were 5 to 9°C (9 to 16°F) more cold hardy than the other selections. while their stems were 6 to 9°C (11 to 16°F) more cold hardy than those of the other selections. The data indicated that these two selections of Chinese evergreen oak may be able to avoid injury when exposed to late spring frosts better than other selections included in the study.
The research reported here was supported, in part, by a grant from the Horticultural Research Institute, Inc., 1250 I Street, N.W., Suite 50, Washington, DC 20005. The authors thank Glen Kent, Sherrie Stevens, Malgorzata Florkowska, and Evelyn Wheatherly for their part in making this manuscript possible.
3Science student, Griffin High School, Griffin, GA 30223.