Phenology and biometrical assesment of <i>Petunia</i> × <i>hybrida Grandiflora</i> cultivars in urban ecosystems in Arctic region

Six new cultivars of Petunia × hybrida Grandiflora (‘Aphrodita White’, ‘Success Salmon Morn’, ‘Dreams Red Picotee’, ‘Hulahoop Blue’, ‘Limbo Blue’, ‘Falcon Burgundy’) were studied in urbanized areas in the Arctic zone (the city of Polyarnye Zori, the Polar-Alpine Botanical Garden-Institute in Kirovsk). Phenological analysis showed that the flowering duration of the cultivars was almost the same, 90–100 days, except for ‘Success Salmon Morn’ (74 days) and ‘Dreams Red Picotee’ (104 days). Biometrical analysis showed that the maximum diameter of flowers was found in Cv. ‘Hulahoop Blue’, and the minimum was typical for Cv. ‘Falcon Burgundy’. In general, varieties with a flower diameter of 6–8 cm predominated. The number of flowers per plant was low in ‘Falcon Burgundy’ (1–3) and high in ‘Limbo Blue’ (12–16). For other varieties, this indicator varied from 4 to 10. Among the features of agricultural technology, the mandatory three to four weeks of hardening and regular application of fertilizers were highlighted both at the stage of seedlings and adult plants. For the ‘Falcon Burgundy’ cultivar, thickened planting was recommended. The study found that these six new varieties are promising for landscaping cities in the Arctic zone since they showes sufficient level of resistace to the conditions of the region.