This two-part presentation will help consultants, growers, and other practitioners in U.S. potato production areas understand the biology of hairy nightshade, how this weed competes with various potato varieties, and how to control it with cultural and herbicide methods. Part 1 provides information about control of hairy nightshade and other weeds problematic in potato. Hairy nightshade has proven troublesome in potato for several reasons: (1) It is in the same family as potato, so control methods that are safe to the crop and detrimental to the weed may be limited; (2) it can germinate the entire potato-growing season, which means control must last season long; and (3) even if controlled early to avoid competition with resulting yield losses, later-germinating hairy nightshade can host insects, diseases, and nematodes that are detrimental to potato.