DAVID Mann and Jennifer Player, "Crooked Hollow", a 530 hectare holding in steep hill country between Mudgee and Burrendong Dam, know more than they wish to about serrated tussock.
The South American native's global spread since last century now has it declared a weed in Australia, New Zealand, South Africa, Europe and North America.
In Australia it is listed as a weed of national significance.
Mr Mann doesn't think it will be possible to eradicate serrated tussock from Australia, but he knows you can give it a fair knock with spot spraying.
"It's tough, we've got big old gum trees dying from the drought, but the serrated tussock just keeps on spreading.
"There was more here when we took the place over, we immediately launched into an eight-week spraying program," he said.
On "Crooked Hollow" the weed could now be considered controlled, as long as the maintenance spraying regime doesn't falter.
But a plant that makes it to maturity, at three years, will shed as many as 140,000 seeds, most of which shoot, according to the Department of Primary Industries.
Wind mainly spreads the seed - 10 kilometres or more if conditions are favourable. Seeds have been known to move 60km downstream on rivers.
Seeds also spread with feed, animals and machinery. Animals can pick up seeds in hooves, fleeces or coats. Serrated tussock seeds remain viable after passing through an animal's gut and drought favours the weed.
Mr Mann's biggest problem is absentee landlord neighbours, who simply don't care about the insidious weed spreading across their properties.
"They're not trying to make a living from the land, these are recreational blocks," said Mr Mann.
"You would have thought the place was either a motocross track or a shooting gallery over Easter.
"I don't mind someone who has worked hard in Sydney having somewhere to take the family or to get out of the rat race, but it's costing me a lot of time and money and I think that's wrong," said Mr Mann.
"There's a responsibility that comes with land ownership."
Central Tablelands Local Lands Service is well aware of the problem absentee landowners are creating, but points out it is the responsibility of local government to enforce recently introduced national bio-security laws.
LLS is organising information seminars to outline landholders' responsibilities when it comes to these laws and in a bid to specifically target absentee landholders Sydney is a new venue.
The next seminar is on May 22 near Richmond.
Landholders who fail in their responsibilities can be fined $1100.