The ReLambro SE project practised classical tools and methods of open space and landscape design by treating natural capital in its physically identified elements, such as hedges, rows, permanent meadows, watercourses, as components of the territorial palimpsest. This article describes and critically presents the working methods with which local projects to strengthen natural capital were developed through the collaboration between the project partnership and the actors in the administration and care of the territory and their subsequent extension and integration in an articulated green network project of the metropolitan sector of the Lambro Milanese.