<p>Seed activism critiques the various ways in which capitalist accumulation through modern agricultural development separates farmers from the seed. Debates centre on legal activism contesting privatisation and seed registration based on exclusionary criteria and various examples of practical work to strengthen farmer seed systems organised around ideas of seed sovereignty and seed commons. The article provides an illustrative example of practical seed activism of the farmer-led network MASIPAG in the Philippines that has been contesting the government’s Green Revolution-oriented commercial seed sector development. Examining critiques in the literature and MASIPAG’s practical work, we propose a distinction between four trajectories of accumulation that separate farmers from the seed and four corresponding fronts at which practical seed activism mobilises: genetic properties of modern varieties, commodified farming and labour, seed and variety legislation, and the contemporary regime of modern plant breeding. Our analysis of the empirical case illustrates the particular dynamics associated with the different trajectories of accumulation, the seed activist responses, and how they intersect in local level seed networks. We argue that MASIPAG’s practical work is an illustrative example of critical engagement with the very capitalist dynamics that its work critiques. Rather than developing an alternative that wholly withdraws, its practical efforts provide lessons about redrawing the boundaries of seed systems and reveals the possibilities for seed systems writ large to be transformed.</p>