Small-Scale Green Roofs with Native Plant Species Installed on Bus Stop Shelters

The University Botanic gardens Ljubljana has been planting vegetation on bus stop shelters in the capital city (Ljubljana) of Slovenia since 2020. The aim of the project is to create a green network across the city, contributing to the conservation of plant biodiversity and providing food resources for pollinators throughout the entire growing season. The plantings were designed exclusively with native plant species, naturally occurring in the territory of Slovenia, flowering from early spring to late autumn. The selected species are also horticulturally attractive, forming small extensive green roof gardens that mimic karst rock ledges, where plants are adapted to drought, shallow soils, and strong sunlight exposure. In 2024 and 2025, monitoring was carried out on eight selected shelters, focusing on plant presence, changes in vegetation cover, and the occurrence of spontaneously sown species and invasive species. The results show that, even after five years without additional maintenance, all plantings are thriving and remain horticulturally attractive. A variety of species flower from early spring to early summer. During drought periods, flowering intensity decreases somewhat but does not cease; in autumn, the shelters green up again with autumn-flowering species. The project has been very well received by the public and is now firmly established in the city. Every year, between 10 and 20 new shelters are planted. By the end of 2025, a total of 75 bus shelters had been greened in all main directions from the city center towards the outskirts.