In our urbanizing society, urban horticulture is gaining relevance due to its potential to increase resource efficiency, contribute to city food security and enhance associated ecosystem and social services. In cities, however, spaces available for cultivation are limited, thus leading to the need to explore innovative growing solutions, for instance, plant cultivation on building rooftops. While rooftop horticulture experiences are “sprouting” all over the world, scientific evidence on the most suitable growing solutions, policies and potential benefits is growing. The present review will address the main features of rooftop horticulture, providing an interdisciplinary assessment of different approaches for development and the multi-faceted forms that rooftop horticulture may assume in different contexts, bringing together existing experiences as well as suggestions for planning of future sustainable cities.