“They say one year’s seed, seven years’ weed, but it’s a bit worse than that with gorse,” said Ross Day, a Blue Mountains Council bush regeneration worker, yesterday as he ripped out seedlings in the Grose River catchment at Blackheath.

About 80 years worse, in fact.

Earlier this year, Cath Ireland, a National Parks and Wildlife Service ranger, was awarded the Order of Australia medal for getting the community involved in the annual Great Grose Gorse Walk she established in 1994 to control the vicious weed that was entrenched in the valley and threatening its famous Blue Gum Forest.

Hundreds of people have volunteered thousands of hours to eradicate gorse from the rugged region, which lies at the heart of the Blue Mountains World Heritage wilderness.

“Ordinary people working together can do extraordinary things and the Great Grose Gorse Walk is testament to that,” Ms Ireland said.

Andrew Rhodes, of the Blue Mountains Council, says gorse is not just a weed, but an “ecosystem transformer . . . it blankets everything and wipes everything else out”. The plant thrives after bushfires and seedlings keep emerging years after adult trees are destroyed.