PRE and POST herbicide options were evaluated to control perilla mint, a potentially deadly plant for livestock. The germination requirements of seed from weedy populations were also investigated to better understand and predict emergence timing. POST applications of aminocyclopyrachlor blends, glyphosate, picloram 2,4-D, aminopyralid 2,4-D, and 2,4-D alone provided superior control of perilla mint when applied in the early reproductive growth stage. Picloram 2,4-D and aminocyclopyrachlor chlorsulfuron also provided soil residual activity and the most effective PRE control followed by pendimethalin and aminopyralid 2,4-D. Seed from weedy populations tend to germinate in a range of night/day soil temperatures from 10–15 C to 25–30 C. Therefore, application and activation of the most effective PRE treatments should be made before these temperatures occur in areas where weedy perilla mint populations are found.

Nomenclature: Aminocyclopyrachlor; chlorsulfuron; glyphosate; picloram; 2,4-D; aminopyralid; pendimethalin; perilla mint, Perilla frutescens (L.) Britton