Urban planners seek better city futures by adopting policy models and best practices from elsewheres, but their interests are overwhelmingly focused on successful narratives. How setbacks impact learning pathways, particularly that of Global South cities, has yet to gain adequate attentions in the theorisation of urban studies. This paper contributes to this research gap by presenting the lessons from Bangkok’s learning journey towards more sensible urban tree care, which involved a series of novel educational activities, including arboricultural workshops, tree-climbing trainings and competitions, and certification tests. By analysing the interviews with the collaborators, including key civil group members, Thai and foreign arborists, frontline tree workers, and government officials, this paper has located the major references sourced to improve the tree maintenance practices in the Thai capital. Emulating the world-class greening achievements of Singapore, the civil groups and tree specialists neglected the complex urban rhythms and place context of Bangkok, resulting in the repeat of inappropriate pruning practices. This setback redirected the search of professional recognition for Thai arborists and tree-climbers at the later stage. Originally imitating, yet eventually differing from, the Taiwanese way of adopting the US-based global certifications, the collaborators devised new certifications that reflect on specific ‘Thai style issues.’ Namely, the previous frustrations of pursuing global expertise prompted the collaborators to prioritize the local practicality over global recognition in their design of the new certifications. As such, this paper argues that setbacks occurred in long-term knowledge circulation are potential to facilitate actors to introspect their existing understandings of urban realities and adopt global expertise more judiciously.