Weeds, specifically introduced pests privet, wild olives, and cotoneaster, have carved out their spot on the nature reserve.

"They're hardy plants. It's amazing what they can survive and it doesn't even seem to bother them that it's so dry at the moment," said the president of Wagga Urban Landcare, Edward Maher.

Mr Maher has performed similar weed-collecting operations around Wagga for the past decade.

In that time, he said, he has not witnessed anything quite so bad.

"It's hard to say how long they've been there," he said.

"It's got to be one of the worst [infestations] in Wagga and it's been like that for at least the last 10 years."

In order to control the spread of the unwanted plants, a group of 18 volunteers have declared 'war on weeds'.

Beginning last Sunday, the team scaled the heights to begin hand-pulling the roots from the ground.

"This is our new venture," Mr Maher said.

"We want to head up monthly, but realistically, we're looking at months of work over a few years to make a difference."

Majority of the work at this early stage will be in containing the site from any further breakout. But the team will very much be working against nature.

"These are prolific reproducers. There are a number of houses nearby where they have become established, and then they're carried by the birds and the insects," Mr Maher said.

"A lot of birds travel to Willans Hill to make their nests, which helps to spread them.

"Then there have also been instances of illegal dumping that doesn't help either."

The weekend's weed-whacking also happened to coincide with the Rural Fire Service's scheduled reduction burning, which Mr Maher hopes will add some literal sizzle to their fire.

"We were working along the eastern side, and the firefighters were over to the west, but we did see a lot of the smoke rising," he said.

"As far as I know, the weeds aren't especially tolerant to fire, so it may have helped us."

Not an easily accessible part of the reserve, removal of the weeds has proven particularly difficult.

"It's pretty much inaccessible to vehicles, so we can't remove it through machinery," Mr Maher said.

"Certainly, it's hard to manage. It's not as straightforward as sending a park manager up with a chainsaw to take care of it. That would be very time consuming on your own."

Aided by Wagga City Council and the city's organics recycling plant, Carbon Mate, the Landcare group are hoping to put a sizable dent in the plant density.