Comparative on Cold Tolerance of Eight Ornamental Plants

The experiment selected Hemerocallis lilioasphodelus Linn, Hemerocallis fulva,Iris tectorum Maxim, Carex spp.,Lonicera japonica,Pachysandra terminalis Sieb.et Zucc, Liriope spicata（Thunb.） Lour.as the test materials, the cold damage index and photosynthetic parameters were measured under natural cooling condition, the cold tolerance of eight ornamental plants was studied, in order to provide excellent cold-resistant varieties for landscaping.The results showed that the cold damage index of Hemerocallis lilioasphodelus Linn increased the most rapidly, while the change of Pachysandra terminalis Sieb.et Zucc and Liriope spicata（Thunb.） Lour.was slow, indicating that the cold tolerance of Hemerocallis lilioasphodelus Linn was the weakest, the cold tolerance of Pachysandra terminalis Sieb.et Zucc and Liriope spicata（Thunb.） Lour.was strong.Based on the analysis of the subordinate function of the indexes measured by eight ornamental plants, it concluded that the cold tolerance of eight plants as follows from large to small was Pachysandra terminalis Sieb.et Zucc＞Liriope spicata（Thunb.） Lour.＞Lonicera japonica＞‘Laoyu’ Carex＞‘Qinglyu’ Carex＞‘Gutonghong’ Iris tectorum Maxim＞‘Jinwawa’ Hemerocallis fulva＞‘Datong’ Hemerocallis lilioasphodelus Linn.