This cultivar group was established to bring together particularly cold-hardy selections raised from seed collected in Afghanistan’s Paktia Province, and grown and selected by Günther Horstmann in the 1970s and early 1980s in Germany. The first selected clones were named by Krüssmann in 1979 (Auders & Spicer 2012). Members of this group are noted for their cold-hardiness, as it is from regions like Paktia Province in the northwest of the species’s range that the most cold-hardy forms occur. ‘Paktia’ itself has been used as a cultivar name, and plants sold under this name have sometimes been raised from seed derived from named clones, but the use of a group name provides a useful indicator of cold-tolerance, and named clones within it will be reproduced by grafting. These clones are certainly hardy to USDA zone 7, and perhaps to zone 6.
Named Paktia Group cultivars include: ‘Eisregen’ (probably the hardiest); ‘Eiswinter’; ‘Karl Fuchs’ (valuable for its blue foliage) and ‘Polar Winter’.
Another very cold-hardy clone is ‘Kashmir’, which was selected from cultivated plants of unknown origin growing in Pennsylvania, in the 1930s. This cannot be included with the Paktia Group because it has a different origin. The same is true of another clone, ‘Shalimar’, also very cold-hardy. This arose from a seed collection made in the early 1960s from trees cultivated in Shalimar Gardens in Indian Administered Kashmir, later propagated at the Arnold Arboretum and named in 1979 (Jacobson 1996).