Modern landscapes are characterized by failures, unfinished projects and unfulfilled dreams. Old plans made by land-owners or municipal and regional planners linger as shadows of a future which never came true. Ruins of factories and railways, derelict farm buildings and fields covered with weeds and bushes, remind us of bankruptcy, conflicts and personal failures. However, ruins are rarely left to decay without further interference of new activities and actors, reusing and reinterpreting the assets, thereby creating hybrid places. This paper argues that planning documents out-of date as well as rusty remnants can be used in combination when aiming for reinterpretations and renegotiations of peri-urban landscapes beyond the conventional concepts and models for countryside planning. Furthermore, it aims to illustrate the use of such seeds for new interpretations within municipal planning. The first part introduces a relational approach to ruins and landscape, inspired by actor-network theory, as a theoretical framework for the paper. Second, a case study of a peri-urban municipality in southern Sweden is presented in order to illustrate the use of such an analysis in everyday planning. Rather than providing a comprehensive analysis of the entire peri-urban landscape, the study focuses on detecting hotspots for reinterpretations of historical remnants (in planning documents and in the field) in order to facilitate a renegotiation of the peri-urban future.