U.S. soybean farmers are currently grappling with dicamba herbicide drift. Using a network diffusion framework that accommodates key features of soybean farmer networks, we estimate the damages incurred from dicamba drift across different regions. Under our baseline assumptions, we estimate an average yield loss of 3% and predict sizable levels of forced switching to dicamba-resistant seed in response to drift. The relative importance of drift on damage and seed choice holds across a range of economic and network assumptions. In the absence of policy, this damage may cause regional adoption rates of dicamba-resistant soybean seed to increase.