Management and control options for tutsan (Hypericum androsaemum) in hill country pastures: a review

Tutsan (Hypericum androsaemum) is a highly invasive semi-evergreen shrubby weed found throughout New Zealand. Although described as a serious pasture weed back in 1937, it was held in check for many years by tutsan rust. In recent years it has begun to spread rapidly again into valuable pastureland, production forestry and conservation areas. Present methods available for managing tutsan in New Zealand are proving inadequate and unsustainable. This review paper provides an overview of tutsan’s biology, ecology, habitat and its current distribution in New Zealand. It then details the possible management strategies and control options in New Zealand, with emphasis on control by herbicides. . Based on a thorough literature review, the paper identifies a number of potential herbicides which, although not currently registered for control of tutsan, have shown good efficacy on this weed and could be developed for use on agricultural land through further research. Herbicides currently registered for control of tutsan in Australia as well as the current recommendations in Victoria and Western Australia are also summarised.