This presentation will help consultants, growers, and other practitioners in the northern United States understand how high tunnels favor certain tomato diseases and how to successfully manage these diseases. Brown leaf mold, Tobacco mosaic virus, and Fusarium wilt of tomatoes are used as examples of how the unique environment of a high tunnel creates management challenges. Varietal resistance, grafting, fungicide applications, and rotations are considered, concluding with the intersection of best management practices across diseases. Participants will learn what and what not to do to grow a healthy tomato crop in a high tunnel.