By considering the lifespan of a garden, this article investigates the myriad spatial practices of forgetting and remembering the colonial and postcolonial pasts that people apply to their urban surroundings in Mahajanga, Madagascar. In the heart of an ancient residential and commercial neighbourhood in this multi-ethnic Indian Ocean port city sits the Jardin Ralaimongo. Drawing on ethnographic and archival research, I explore the trajectory of the garden to elucidate the ways in which different socio-political groups have drawn on this site to negotiate differences, frame collective memories, and stake their claims to the urban landscape. I show how, as city inhabitants have reworked the spaces of the garden, so too has the park itself – its layout, material artefacts and location within the city – constrained the possibilities of what can be remembered and silenced, and who can be bound to one another, in contemporary times. Over its hundred-year history, this site has been founded, forgotten and reincarnated as a memorial to a succession of revered leaders, thus serving as a kind of spatial register of the historical socio-political changes that have given rise to the city. This article suggests that the deterioration of colonial-era architectural forms through long-standing neglect and abandonment may be understood as an active spatial practice of effacing some dimensions of the past, while the subsequent recuperation of deserted public spaces by certain groups is an effort to position themselves as legitimate residents and express their attachment to the city.