It’s the weed Auckland gardeners love to hate - tradescantia, better known as 'wandering willie'.

Arguably the most notorious pest weed to have escaped into the wild, it causes considerable damage to the natural environment, spreading along streams by water movement, infesting waterways and smothering native species.

Community groups working in the Roy Clements Treeway, Mt Albert and Oakley Creek, New Windsor local parks requested council support in battling the pest plant. Auckland Council is, for the first time, organising the release of a fungal pathogen biocontrol in an urban environment to help control the weed.

Auckland Council’s Senior Regional Advisor Pest Plants, Holly Cox says the council is excited about the long-awaited release of this biocontrol agent.

 “Tradescantia is very difficult to control and despite the best efforts of volunteers to manage the weed, they’ve been unable to make inroads.

 “The yellow leaf spot fungus is an ideal control as it disperses itself with water movement and humid air movement spreading to other infestations both inside and outside the stream reserve,” adds Holly.

The plants, infected with the yellow spot fungus (Kordyana brasiliensis), will be planted in the waterway and together with the tradescantia leaf beetle already present, it is hoped the fungus will further reduce the impact on the ecosystem.

The fungal pathogen, native to Brazil, is host-specific meaning it only impacts tradescantia and is no risk to other species.

Tradescantia is identified as a pest plant in the Auckland Regional Pest Management Plan 2020-2030, and eradication is tackled under a whole-of-region sustained control programme which aims to reduce the spread and impact of the pest plant.

Read more about this pest species here.