[en] This article aims to present urban agriculture based on its activist expression and, therefore, as a political mechanism for spatial transformation in São Paulo and Paris. For this, we use participatory methodologies, with an emphasis on action research. Based on fieldwork and active participation in urban horticulture networks and initiatives, we also expanded the critical analysis of non-commercial intra-urban agriculture through the mobilization of its ideological essences, the articulations of civil society and the existing public policies and programs. We will return more specifically to the materialities of community gardens, which have the political potential to transform urban space, as they can expand reflections on: the use of public space; the origin and the quality of food; the organic production; the cooperation between citizens; the greening process of the city using edible plants; the forms of interaction between society and public authorities; and the debate on the right to the city. Crossing experiences from São Paulo and Paris, we also clarified the similarities and the differences in the understanding of "urban agriculture as activism" in distinct contexts, both in terms of the gardeners' organization in their respective local scales of activity and in relation to the responses of local governments. The awakening of activism and collective interest in the propagation of community gardens is recent in both cities, dating from this 21st century. But in Paris, the political articulation and the first gardens were created ten years before São Paulo (2000s in Paris and 2010s in São Paulo). Therefore, the number of community gardens is very different between those two cities. Until 2020, 14 initiatives in São Paulo were visited by this research; in Paris, 62 gardens were visited, but data from the local government accounted for 129 community gardens by the end of 2019. In São Paulo, there are no specific municipal policies or programs for community gardens and the initiatives are quite autonomous. However, their existence reinforces an approximation with the public power, since they reveal articulations in favour of the citizen reappropriation of public spaces, notably the squares. In Paris, in its turn, there is a municipal program for community gardens and associations are created to represent them. The local government guarantees a minimum set of support for the success of these actions, in addition to granting authorization for their existence in public spaces, notably squares and parks. In the two cities, São Paulo and Paris, there is an ideological appreciation of organic production in community gardens. Agroecology and / or permaculture appear as a symbol of the activist and collective practice of promoting ancestral knowledge and also to differentiate the organic production for the market. Finally, it is possible to verify that horticultural initiatives in public space reinforce community bonds and introduce new daily socio-spatial dynamics. Thus, it is confirmed that urban agriculture is a plural social practice. Its multiple dimensions allow analysis and studies from different perspectives, including those that focus on urban activism.

[fr] Cet article vise à présenter l'agriculture urbaine à partir de son expression militante et par conséquent en tant que mécanisme politique de transformation spatiale à São Paulo et à Paris. Pour cela, nous utilisons des méthodologies participatives, en mettant l'accent sur la recherche-action. À partir d'un travail de terrain et de la participation active dans des réseaux et des initiatives pour l'horticulture urbaine, nous élargissons aussi l'analyse critique concernant l'agriculture intra-urbaine non commerciale, en mobilisant des essences idéologiques, des articulations de la société civile et des programmes et politiques publiques qui y sont liés. Nous reviendrons plus spécifiquement sur les matérialités des jardins partagés, qui ont un potentiel politique de transformation de l'espace urbain car ils peuvent élargir les réflexions sur : l'utilisation des espaces publics, l'origine et la qualité de l'alimentation, la production biologique, la coopération entre les citoyens, le processus de végétalisation comestible dans la ville, les différentes formes d'interaction entre la société et les pouvoirs publics, et le débat sur le droit à la ville. En croisant des expériences de São Paulo et de Paris, on clarifie également les similitudes et les différences dans la compréhension d'une " agriculture urbaine militante " dans différents contextes, à la fois au niveau de l'organisation des jardiniers dans leurs respectives échelles locales d'activité ainsi que par rapport aux réponses des gouvernements locaux.