Trees are known for their positive impacts in cities including: the provision of shade, reducing heat island effects, improving amenity, reducing social vulnerability, processing carbon and improving health outcomes. Perhaps unsurprisingly, greening policies at the local and state level have proliferated. Despite these initiatives, tree cover remains stubbornly uneven. A cursory analysis of vulnerability and tree-cover by location shows that those who are most vulnerable to extreme heat events often live in those parts of cities that are most poorly shaded. Drawing on a new set of 50 online questionnaire and face-to-face interviews with local council officers in Melbourne conducted in 2014, the aim of this paper is to identify the actors and processes shaping the provision of the urban tree canopy. The results emphasise: i) the wide range of public and private organisations that, in collaboration, provide and maintain tree-cover; ii) the key role of residents within these governance frameworks; iii) the impact of urban development histories on opportunities and limits for urban greening. Theoretically, the paper advances relational models of urban governance in the context of resilient cities showing the urban canopy is the product of diverse actors and agents operating across hybrid and fluid public and private spaces. Recognising this, the paper highlights opportunities for engagement with residents in greening initiatives; and a new integration of ecological and social data through which greening strategies can target those of greatest heat vulnerability.