This paper draws upon Foucauldian theories of governmentality and biopower to examine the recent growth of greenhouse cultivation on the island of Jamaica. Greenhouse farming has been widely promoted as a means to enhance the efficiency, technological sophistication, and profitability of the island’s traditional small-scale farmers. Following Foucault, and drawing on a series of interviews with greenhouse growers, we read this intervention as form of governmentality acting on the conduct and attitudes of Jamaican farmers. As a form of governmentality, greenhouse farming also represents a new and distinctive regime of biopower, one that intervenes with greater precision into the metabolism between the natural processes of the rural population and the vital properties of growing plants. Viewed as a form of biopower, the greenhouse calls particular attention to the ways in which assemblages of materials and technologies enable new forms of control and surveillance over the life processes associated with crop cultivation, thereby generating new kinds of affective relations and agrarian subjectivities. This capital- and chemical-intensive biopolitics, we argue, threatens to re-engineer Jamaica’s agrarian milieu in ways that favor elite agricultural interests at the expense of long-standing traditional farming practices and the forms of socio-ecological metabolism upon which they are based.