Landowners could claim damages if Japanese knotweed has encroached on their property following a Court of Appeal ruling.
Network Rail has lost an appeal over damages awarded to two homeowners after Japanese knotweed encroached on their land in Bridgend county.
Stephen Williams and Robin Waistell won a claim against Network Rail which owns the land behind their homes in Maesteg.
Mr Waistell was awarded £15,000.
His lawyer Rodger Burnett said: "This is a great result for Mr Waistell and homeowners up and down the country.
"Hopefully now organisations like Network Rail will take their responsibilities seriously and remove the knotweed on their properties."
Announcing the decision, Master of the Rolls Sir Terence Etherton said: "Japanese knotweed, and its roots and rhizomes, does not merely carry the risk of future physical damage to buildings, structures and installations on the land.
"Its presence imposes an immediate burden on landowners who face an increased difficulty in their ability to develop, and in the cost of developing, their land, should they wish to do so, because of the difficulties and expense of eradicating Japanese knotweed from affected land."
He added that Japanese knotweed "can fairly be described as a natural hazard which affects landowners' ability fully to use and enjoy their property and, in doing so, interferes with the land's amenity value".
However, the judge said the homeowners would not be entitled to damages because the knotweed had lowered the value of their properties.
A Network Rail spokesperson said it was "aware of today's ruling by the Court of Appeal and is considering its implications".
"As many gardeners know, Japanese knotweed is invasive and requires several years of treatment to remove," they added.
"Once identified, Japanese knotweed growing on our land is entered into a treatment programme. We will continue with this established regime, which complies with legislation and helps us run a safe, reliable railway."