Rose ‘Casino’ as an Element of Landscape Architectural Composition in the Courtyard of the Church of St George in Belgrade Under Changing Climate Conditions

Abstract The study analyses the in situ sustainability of the climbing rose ‘Casino’ in the courtyard of the Church of St George in Belgrade. The aim of the research was to assess the impact of changing climate conditions on its phenological flowering pattern. The evaluation assessed frost damage and timing of the phenological flowering phases - bud break, beginning of flowering, full bloom and end of flowering-as well as daily flowering abundance. The findings indicate that bud break timing was correlated with accumulated cold hours, which reached a sum level typical for early - flowering plants (to which the studied cultivar does not belong), as well as the accumulated heat sum for subsequent phenological phases. The flowering began 93 days earlier, and continued uninterrupted until the end of 2024 and into January 2025, with varying abundance. A comparative analysis determined the optimal daily maximum and minimum temperatures for peak flowering −22.9°C (maximum) and 11.7°C (minimum) - and for abundant flowering −20.8°C (maximum) and 9.8°C (minimum). Regression analysis confirmed a decline in flowering abundance when daily maximum and minimum air temperatures exceeded the optimal ranges. These findings have practical applications in urban landscape design, especially considering the projected global warming trends. Despite the resistance of the ‘Casino’ rose’ to changing climate conditions, there is no certainty regarding the stability of the flowering phenophase in the coming years. In line with sustainable global trends, the ‘Casino’ cultivar is recommended for inclusion in Serbia’s first rosarium and for future research programmes aimed at cultivar conservation and breeding improvements. Additionally, given its significance as a 30-year-old element of the landscape architectural composition, it is proposed for protection as a natural asset and as valuable source material for vegetative reproduction.