Scheme to eradicate Japanese knotweed enters its fourth year

An initiative which is seeking to free the Garw Valley from Japanese knotweed is about to enter its fourth year of operation.

Often found growing along riverbanks, railway tracks, woodlands and even in car parks, this invasive non-native species forms thick, dense thickets that grow up to three metres high and which completely crowd out native plants and any other herbaceous species.

As even very small fragments of root or shoot can result in a new infestation, it is a criminal offence to cause Japanese knotweed to spread, and great care must be taken when dealing with it.

In 2018, Bridgend County Borough Council began working alongside Natural Resources Wales, Awen Cultural Trust, Garw Valley Community Council, Bridgend Valleys Railway Company, Keep Wales Tidy and the Ogmore and Garw Valley angling associations to deliver long-term works designed to control and ultimately eradicate Japanese knotweed along the river corridor of the Garw Valley.

Cllr John Spanswick, Cabinet Member for Communities, said: “This will be the fourth year that the partnership has been targeting knotweed growth throughout the Garw Valley, and we remain committed towards improving and protecting local habitats so that vegetation and wildlife can flourish.

“Because of the difficulties in removing Japanese knotweed, the best way of dealing with infestations is to repeatedly spray it using an approved herbicide formula that is appropriate for areas adjacent to a watercourse. This is carried out by qualified operators between August and the end of September, and signage will be erected to let people know when work is underway.

“By its nature, this is a lengthy and time-consuming process, but the organisations who have come together to tackle Japanese knotweed are determined to remove this blight from the Garw Valley in its entirety.

“We are also committed towards tackling Japanese knotweed elsewhere in the county borough, and are in the process of using the Public Realm Fund to establish a new role dedicated to mapping and dealing with invasive non-native species as part of a £65,000 initiative.”

For any enquiries regarding the work, please call Natural Resources Wales on 0300 065 3000 or email

Did you know?

  • Japanese knotweed (Fallopia japonica) is native to Japan, Taiwan and northern China, and was introduced to the UK in the early 19th century as an ornamental plant.
  • Causing Japanese knotweed to spread is now an offence under the Wildlife and Countryside Act 1981 – do not strim, cut, flail, mow or otherwise disturb it.
  • Japanese knotweed is classed as controlled waste under the Environmental Protection Act (1990) and can only be disposed of at a licensed tip, with a licence from Natural Resources Wales.
  • Anyone who intends to manage Japanese knotweed without the use of herbicides should contact the Natural Resources Wales for advice.
  • Never place cuttings of Japanese knotweed into compost, and never dispose of it as green waste.
  • When spraying Japanese knotweed with herbicide, this should be done at the end of the growing season and just before the plant dies back in early September.
  • Spraying should be carried out in calm, dry conditions, when no rain is expected for 24 hours after spraying.
  • Herbicide treatment earlier in the season will not be effective, but a follow-up spray may be required in subsequent years to kill off remaining shoots.
  • If you are spraying within 10 metres of a watercourse, prior approval is required from Natural Resources Wales and you must only use products which are specially formulated for an aquatic environment.
  • To find out more about Japanese knotweed, visit the Natural Resources Wales website.