This research is interdisciplinary in nature and supports the process of selecting individual plants to achieve sustainable visual and ecological effects in the urban landscape. The importance of this study is further emphasised by climate change, which necessitates modifications to the existing selection of ornamental plants. These individuals must be capable of adapting to urban ecosystems in order to mitigate the impacts of climate change on humans and other organisms and to maintain a high level of biodiversity. Accordingly, this paper highlights, at the individual level, the significance of Japanese quince (Chaenomeles japonica (Thunb.) Lindl. ex Spach) as an element of urban green infrastructure in the Balkan Peninsula. Based on a real case study conducted over the period 2007–2025 and through an integrative approach involving 3841 phenological observations and climate parameters over 19 consecutive years, local phenological flowering patterns were identified, upon which the species’ functional potential depends. The key patterns and abundance of flowering are the result of interactions with daily maximum and minimum air temperatures and precipitation levels, as confirmed by correlations with percentile-based classifications of climatic variables for the study years. The statistical non-significance of the trends points to the influence of extreme climatic events but also to the adaptability of the selected genotype compared with other Japanese quince genotypes in the vicinity. Regression analysis determined the optimal daily air temperatures for continuous flowering during 2024 and 2025. The results confirm that the selected individual is sustainable, and it is, therefore, proposed for inclusion in the assortment of ornamental plants important for preserving ecosystem services in urban landscape design, particularly in view of its demonstrated utilitarian benefits.
Skočajić et al. (Mon,) studied this question.