The invasive plant species, Tradescantia fluminensis, first appeared in the Whakapohai Reserve in South Westland, New Zealand, during the 1960s, and by 2002, it had spread throughout the 43-ha riparian reserve. It was presumed at high risk of spreading to neighbouring National Parks because of its ability to spread by floodwaters. A restoration project with the aim of eradicating Tradescantia in the reserve began in May 2002, at which time eight transects were established. The cover of Tradescantia was measured before control, and after on six subsequent occasions. The initial cover of Tradescantia was estimated to be about 17% of the entire reserve in 2002 and declined with annual control to <0.1% in 2011. The effects of this management regime on the forest community are described along with documentation of the costs and time put into achieving these outcomes.