It's a Japanese jungle out there
Japanese knotweed is on the march once again – and now it's plaguing a major road project.
Contractors working on the A8 road dualling scheme in Co Antrim are battling an outbreak of the highly invasive plant.
They are warning members of the public not to take any topsoil away from the site, for fear of spreading the weed, which can grow to eight feet or more in a single season and is capable of causing serious structural damage to buildings.
The pernicious plant has been listed as one of the top 10 most unwanted species in Ireland, along with invaders such as New Zealand flatworm, the grey squirrel and the muntjac deer.
Signs were recently erected along the route of the A8 between Ballynure and Larne, warning people not to trespass on the land because it is being treated for an outbreak of Japanese knotweed.
They were also warned not to take away any material from the site in case they caused the weed to spread. It is an offence to plant or cause Japanese knotweed to grow in the wild in Northern Ireland.
It has been estimated that invasive species are costing the Northern Ireland economy £46.5m a year. Gareth Dalzell, director of Japanese Knotweed Northern Ireland, which specialises in eradicating the plant, said it has now spread throughout the province.
"There has always been a lot of it about, but more and more people are becoming aware of it – and people like surveyors are picking up on it more," he said.
"We're finding it everywhere from small back gardens in isolated locations, right through to railways, rivers, landfills, private housing and commercial developments. There really is nowhere that we haven't found it.
"I haven't seen any structural damage, but I've seen damage to road surfaces, footpaths and driveways, and retaining walls being pushed out of place."
Mr Dalzell said people taking topsoil from road building works could unwittingly be contributing to the spread. "Whenever there is excavation work going on, people will often come along with a car and a trailer asking for some of the topsoil, or will even just help themselves," he said.
A spokesman for the Department for Regional Development said it was not an uncommon issue for road schemes, but there have been no reported incidents of people taking topsoil from this site.
"The contractor has taken steps to ensure that the Japanese knotweed is contained within the areas that it currently exists," he said.