We urgently need to prepare vulnerable coastal systems in the Wadden Sea for the impacts of the triple ecological crisis. SALTGARDEN advocates for biodiverse, dynamic salt marshes to improve ecosystem functions and services at all levels. With a transdisciplinary approach combining mesocosm experiments, field observations, model simulations and socio-economic assessments, we seek to quantify and predict future developments of biodiverse-dynamic versus static-cultivated salt marshes. Together with trilateral stakeholders, we will co-create Nature-based Gardening strategies to promote adaptive landscapes and sustainable wetland management beyond coastal protection. SALTGARDEN will inform adaptive policy pathways for future-proofing the Wadden Sea salt marshes and communities.