Over the past two decades, Green Infrastructure (GI) has gained prominence as a strategic spatial planning concept aimed at integrating ecological connectivity, ecosystem services, and socio-spatial objectives within coherent territorial frameworks. Yet empirical evidence indicates that its operationalisation remains uneven, particularly in small municipalities and transitional governance contexts that are underrepresented in mainstream GI scholarship. This study examines how GI is conceptualised, operationalised, and implemented within the spatial planning system of North Macedonia, with a specific focus on the municipalities of Struga and Vevchani. Adopting a qualitative multiple-method design, the research combines Critical Discourse Analysis of national, regional, and municipal planning documents with a structured practitioner workshop aimed at examining institutional interpretations, implementation constraints, and cross-sectoral coordination dynamics. This triangulated approach enables a systematic assessment of how GI is framed, codified, and enacted in practice, while also capturing how practitioners negotiate its integration within existing regulatory mandates. The findings reveal a persistent communicative-operative gap. Although Green Infrastructure (GI) is discursively endorsed and aligned with European environmental agendas, its operational embedding occurs primarily through pre-existing sectoral and landuse categories. Policy provisions remain predominantly aspirational, regulatory language is weak, cross-sectoral coordination limited, and monitoring mechanisms largely absent. GI is selectively embedded within protection-oriented domains, while multifunctionality, spatial connectivity, and equity dimensions are weakly codified in binding instruments. Rather than constituting an implementation failure, this configuration reflects a process of institutional adaptation, whereby GI stabilises in forms compatible with entrenched regulatory cultures and administrative mandates. The study reconceptualises Green Infrastructure (GI) mainstreaming as a process of institutional translation rather than linear policy diffusion. It advances a configurational lens for analysing multifunctional infrastructure within hybrid governance regimes and demonstrates that conceptual adoption without regulatory specificity may produce discursive convergence while leaving spatial allocation logics structurally unchanged. These insights contribute to ongoing debates on GI governance, planning reform, and EU policy alignment in peripheral and institutionally fluid contexts.