We develop a novel spatial-dynamic model of landowners managing a disease in a perennial crop. We use the model to investigate the dynamic gains from cooperation to address the spatial externality resulting from disease vector dispersal. We find that solving for the complete time path of control decisions is important; cooperation leads to each landowner investing more in treatment in early years than in cases where one agent free rides on the other’s control. Our model is based on Pierce’s Disease of grapevines in California’s Napa Valley but is applicable to a range of diseases in perennial crops.