The selection of species which show the highest possible tolerance to negative habitat conditions, also among plants of foreign origin, is a pressing issue. One of the species we would like to recommend for planting in urban areas is the white mulberry species (Morus alba) due to both its outstanding adaptability and its ecosystem services. There are no reliable studies on the distribution of this species in urbanized areas in Poland, nor sufficient analyses of the methods of its renewal, both deliberate and spontaneous spread through self-seeding. Collecting data on the population of an alien species within individual regions and forecasting potential changes in the population’s size and structure, as well as its possible impacts on other organisms, is one of the basic measures to reduce biological invasions, which is one of the six priority objectives of the European Biodiversity Strategy and an element of the Strategy on Invasive Alien Species. The aim of this study was to determine the size and structure of the white mulberry population in the city of Wrocław and to analyse the relationship between this structure and intensity of anthropopressure and thermal conditions.