Private residential gardens are among the largest and most widespread categories of urban green space, yet their ecological potential is often unrealised because garden design is preference-driven and rarely Evidence-based and collaborative. Existing research either synthesise residential gardens through an ecological lens—treating residents as variables that shape biodiversity—or apply participation and co-design frameworks to public space. There is a lack of study systematically examined resident participation and resident–professional collaboration in residential garden design. Employing a PRISMA method, we reviewed 76 studies (2010–2026) and developed a framework that maps each study along the design for/with/by participation spectrum, cross-tabulated by design topic (nine themes), research method and methodological quality (MMAT). Results suggest that ecological-performance topics and resident–professional collaboration are almost mutually exclusive—biodiversity, water, and climate studies sit almost entirely at the design-for end (often researcher- or simulation-led), whereas the few with/by collaborations occur almost only within participatory design itself. Quality appraisal shows the most rigorous evidence (choice experiments) lies at the preference end, indicating that for-dominance reflects research orientation, not evidential strength. We conclude that what is scarce is not resident participation but the collaborative channel through which ecological knowledge enters garden design, and propose a participation-deepening lens for future research.