The aim of the PflanzenMit! is to support the active involvement of the city population in urban green maintenance. As the center of the project, various services are being developed under a mobile app that supports the citizens of a district in identifying and caring for urban green spaces. Citizens can register using PlantMit! come together to form groups that take on the joint care of one or more urban green spaces. An optional integration of the municipal administration should create a direct link to the responsible municipal administration. PlantWith! sees itself as an open platform where new citizens can join a group to look after a green space at any time. External users can send feedback and suggestions to the groups at any time on areas delimited by geofencing, via QR codes and via a web platform. To support communication, motivation and knowledge sharing, the platform offers various services such as plant exchange initiatives, automated events and AI-based recommendations. An open and modern interface (Cloud Native API as REST / GraphQL) allows the system to be expanded and other services to be integrated.