The peculiarities of oxidative enzymes’ activity at the dormancy phenological stage under conditions of low positive temperature were studied. Most effective methods (NPK, zircon growth regulator) for enhancing the cold tolerance of the Swida, Deutzia, Buddleja and Hibiscus species have been determined. It has been established that activity of catalase and peroxidase depends on the cold adaptation of introduced arbo-real plants of different winter-resistance. The possibility to use the ratio of enzymatic activities Acold./Anorm. as a test-parameter in forecasting the winter-resistance of plants is displayed.