A pensioner has won a £10,000 payout from the Welsh government after aggressive Japanese knotweed invaded his property.
Transport for Wales was ordered to pay the sum in damages to Richard Pember, 74, after the invasive plant spread from a railway line into his garden in Hopkinstown, Pontypridd.
In May, Pontypridd County Court heard Transport for Wales, which is owned by the Welsh government, had failed to adequately treat the growth which led to the eventual intrusion on to his property.
A judge ordered the company to pay £10,000 in damages to Pember, who lives in Trehafod in the Rhondda Valley while his son rents the troubled property.
Pember bought the home 11 years ago but now worries it is worth a fraction of what he paid for it after Japanese knotweed took over the garden.
The plant can grow up to 2.1m (7ft) tall and its roots can cause damage to walls, fences and paved areas. If selling a home, the seller is required by law to state whether Japanese knotweed is present on their property.
Pember first noticed the Japanese knotweed in 2016 but by 2020 it had spread by more than 20ft over his land.
“It started off so small that I didn’t think anything of it," he said.
"Then it just grew from nowhere to a point where it was almost coming inside the property. You hear stories about this stuff completely taking over homes and I was terrified that might happen to mine.
“It has massively devalued the house in my opinion because nobody wants to move into a property that has a Japanese knotweed infestation. It’s like living with a monster that always comes back.”
He said his son has had the garden renovated but the plant has already started coming back, with treatments of the plant costing about £800 a time.
Transport for Wales claimed it had not missed a treatment of the Japanese knotweed on its land, but said it decided not to appeal the judge's decision.
Tom Hardwick, director of Angelus Law, which represented Pember, said: “The victory showcases the importance of holding responsible parties accountable for their obligations to prevent the spread of such destructive plants."
A spokesperson for Transport for Wales said: “TFW is naturally disappointed with this court result given the facts as presented to the court.
"TFW has categorically not failed in treating the Japanese knotweed on its land and has a thorough and effective treatment programme in place across the whole of the Core Valley Lines network where this property neighbours.
"An appeal was considered but on this occasion was not pursued.”
What should I do if I find Japanese knotweed in my garden?
According to the Royal Horticultural Society (RHI), Japanese knotweed is difficult to control through simple manual removal.
It says that digging out the plant without professional help creates issues as it is classes as "controlled waste" under the Environmental Protection Act 1990, which means it must be disposed of at licensed landfill sites.
Japanese knotweed should not be included in normal household waster or put in green waste collection bins.
The RHI says it takes at least three to four seasons to eradicate Japanese knotweed with weedkiller, but that professional contractors will have access to more powerful weedkiller that can reduce that period by half.
Do you have to legally remove Japanese knotweed?
According to the Anti-social Behaviour, Crime and Policing Act 2014, it is not illegal to have Japanese knotweed in your garden, the RHI says.
However, homeowners should aim to control the invasive non-native plant to prevent it spreading in the neighbourhood.
If they fail to do so, property owners could be prosecuted.
Since 2013, someone selling a property is required to state whether Japanese knotweed is present there.