The prospects for cultivating North American species of Carya in the Moscow region

The aim of this study is to determine whether it is possible to cultivate the North American species of the genus Carya in the Moscow region. The study was conducted on 4 species: Carya laciniosa, C. illinoensis, C. cordiformis and C. ovata, that grow in the arboretum and in the nursery of the Main Botanical Garden of Russian Academy of Sciences. There were 15 samples comprising 55 specimens. During 3 years, most of the studied Carya plants were documented to increase by the value ranging from 30 to 80 cm, whereas most central leaders grow annually by 5-45 cm. Maximum annual growth of C. laciniosa is 78 cm, C. illinoensis - 50 cm, C. cordiformis - 58 cm, C. ovata - 76 cm. The maximum central leader growth is observed for C. laciniosa, the minimum one - for C. cordiformis. Largest annual growth increment is characteristic of C. lacinosa, and the smallest one is for C. ovata, C. cordiformis and also C. lacinosa. Plant growth has no features in common and it varies within both species and specimens. With high rainfall during the year, a minimum sum of active temperatures above 15℃ and relatively cold April, most plants showed reduction in growth of leader shoots. There are no clear connections between growth of species or samples and temperature, the sum of active temperatures and annual precipitation. Generally, the climate of the Moscow region has an insignificant influence on the growth of different Carya species.