The paper presents an empirical study of the emotional perception of urban green areas based on digital emotional mapping. The article reveals the relevance of studying the subjective quality of parks and gardens based on the perception of green areas by their visitors. The latter was conducted using Imprecity digital interactive platform, elaborated by the authors. The object of the study are green areas of St Petersburg. Data from the Imprecity.ru digital platform developed by the authors of the article was used as the base layer of data on the perception of green areas. This platform is a tool for digital participatory interaction with residents and visitors of urban areas and allows to get information about the emotional perception of the environment. Emotional ratings of green areas were compiled, maps showing the spatial distribution of emotionally perceived parks and gardens were created. The textual component of the mapping data (user comments on emotional markers) was considered through qualitative semantic analysis and the values and the deficits of the green areas, inducing emotions of joy, sadness, fear, disgust, and anger, were allocated. The interpretation of the discovered emotionally relevant values and deficits is given in the framework of cultural ecosystem services approach.