The winner in the environmental category: the 'CityTree' planting system improves the air and connects citizens and companies thanks to digital technology. Air pollution is a particular burden on the environment and health in cities. But there is often a lack of space and money for more trees and parks. Dresden-based start-up Green City Solutions has developed a special green space called the 'CityTree': The mobile vertical greening provides growing space for mosses and flowering plants that are designed to absorb particulate matter. At the same time, it acts as a WLAN hotspot and advertising medium. Logos or QR codes can be displayed on it using plants or plastic pixels. Thanks to sensor and remote control technology, the multifunctional planting system collects data on air pollution control.