It’s true many weeds considered noxious in this area – nodding thistle, serrated tussock and blackberries – tend to start on properties and in forestry and gradually make their way onto roads.

However Mr Kurtz said that one of the most aggressive weeds in this area, st johns wort, first put down roots along the roadways and is now infesting local farmland.

Wort is considered so troublesome because the seed is spread over short distances by wind, but over long distances by water, machinery, humans, livestock or feral animals.

To add to the problem, because the wort roots sucker and grow from fragments, cultivation can spread the weed unless the roots are brought to the surface and dried out.

Graziers are keen to keep the weed off grazing land as it can cause photosensitisation in sheep, cattle, horses and goats, which can be lethal. Wort also adds vegetable fault to wool, can overtake pasture and reduces property values.

Mr Kurtz said that st johns wort came to the Oberon district from travelling stock being driven along local roadways.

He said wort is showing up along roadways right across the district, and he has noticed large areas of the weed along roads such as the Abercrombie Road and Mozart Road, which he travels regularly.

Like chilean needle grass, another extremely noxious weed that is beginning to show up in the Oberon district, wort is still in early stages of spreading and Mr Kurtz is adamant that something is done about the weed now before it is too late.

The spraying of noxious weeds is the responsibility of the Upper Macquarie County Council (UMCC), who manage four council areas, including Oberon, and many local landholders are at a loss to understand why the wort is being allowed to thrive along roadsides.

However Don Baldwin of the UMCC said the county council is doing everything they can to spray all roadsides in the district.