This article examines the processes of urban commoning and its co‐produced features of urbanity, making the claim that, through these processes, informality becomes translated into institutionalized city planning. Commoning is analysed through a comparative study that utilizes contingent features of urbanity and three modalities accommodating the informality–formality meshwork during urban change. The article contributes to research on urban transformations by integrating commons, informality dynamics and the constitution of state institutions. This focus is elaborated with reference to collective gardening practices in the context of two of the less studied European cities, Narva in Estonia and Tampere in Finland. The results of the study indicate that urban commoning takes place through delegating a public mandate and enacting uncertainty, two processes that informalize city government practices. Particular differences appeared in regard to the institutional porosity that enables unregulated spaces of collective gardening to be mobilized as part of urban politics. We argue that networked movements appear as an essential part of the urban logic of action producing meaningful connections in an informal–formal meshwork and bringing together multiple sites in the commoning process.