This study explored the function of school leading in the implementation process of education for sustainable development (ESD) in five Swedish schools employing a whole school approach (WSA). A follow-up study design was used, in which schools that had initiated an ESD project in 2016 were subsequently visited twice for interviews with principals during the project and after it was finalized. The theory of practice architectures in combination with the concept of school improvement capacity was used as the theoretical framework in the analysis. The study showed how school leading should be about enhancing the local school's capacity to improve. It also showed how specific practice architectures prefigured a WSA to ESD and how school leading in this context was about arranging--or orchestrating--practice architectures in ways that enabled such an approach. The issues of time and endurance were pivotal. Based on the empirical results from this study and school improvement theory, guidelines were developed that can be used to drive a WSA to ESD process forward through three different school improvement phases: initiation, implementation, and institutionalization. The limitations and suggestions for further research are also discussed.