Greening the Arctic cities is a strategic task for the sustainable development of polar regions. A major role in this belongs to the Polar-Alpine Botanical Garden-Institute (PABGI), which is engaged in introduction tests of new plant species that can decorate northern cities. The research aimed to analyze the perspectives of 6 species of the genus Arnica (A. chamissonis Less., A. cordifolia Hook., A. nevadensis A. Gray, A. parryi A. Gray, A. rydbergii Greene, and A. sororia Greenе), introduced in PABGI in different years for landscaping of cities in the Murmansk region. For this purpose, seasonal rhythms of phenological development and sowing qualities of seeds were studied. It was revealed that A. rydbergii, A. parryi, A. sororia, and A. nevadensis were successfully adapted to the conditions of the region since they managed to go through all stages of phenological development during a short growing season (107–109 days) and were characterized by high rates of laboratory germination (84–97%) and are recommended for inclusion in the landscaping assortment. Low germination rates were found in A. cordifolia (47%) and A. chamissonis (72%) due to late seed ripening (end of August). For use in landscape design of Arctic cities, the studied species of the genus Arnica were divided into two groups: (1) for floral decoration of landscaping objects (A. rydbergii, A. parryi, A. sororia); (2) turfing slopes (A. nevadensis and A. chamissonis). Arnica cordifolia is also suitable for protecting the slopes from erosion and surface protection.