This essay theorizes crop seeds as deep time technologies, surveying a range of materialist approaches to the study of agriculture, from historical materialism to agroecology and actor-network theory. Recent studies of plant domestication suggest that the long history of human-plant relations and agrarian knowledge defy the reduction of seeds to products of nature or objects of property. Approaching seeds as technologies allows us to understand the actors and processes of improvement that demarcate biological material according to commercial and scientific logics. Framing seeds as a collaborative technological project with a 19,000-year history unseats industrial time as the dominant frame in the history of technology. It recasts political economy not simply as a construction of human social relations of production but also as it imagines the material used to produce life itself.