A three-mile long Japanese knotweed jungle feared to be the biggest in Britain could leave nearby homes unsellable, locals have been warned.
For years the invasive species has been exploding along The River Roding, Barking intertwining with native reeds and causing ecological havoc.
The infestation has been overtaking acres of scrubland on both side of the riverbank in east London and it now poses a serious threat to riverside properties if left untreated.
Volunteers at a charity tasked with preserving the river believe the knotweed jungle has spread all along the three-mile stretch of water.
Just yards from the river is a series of newbuild estates, yet residents said they had no idea about the danger lurking on their doorstep.
Paul Powlesland, river guardian at the River Roding Trust told the DailyMail: ‘It’s [the knotweed] been spreading for years and it’s now taking over an entire bank.
‘There are acres that should be full of reed beds, rich nettle and plants but the only thing alive is knotweed.’
He added: ‘The knotweed is right next to properties and if they spread any more it’s going to cost millions of pound of remediation and make all the flats unmortgageable.’
Pictured: A combination of reed beds and Japanese knotweed encroaching on nearby homes
Pictured: Jungle-like enclaves that have formed along the riverbed of the River Roding
Japanese knotweed – described by the Environment Agency as ‘indisputably the UK’s most aggressive, destructive and invasive plant’ spreads via underground rhizomes.
The rhizomes form a crown at the centre of the plant and are able to extend up to seven metres.
They can grow through tiny cracks, walls and even concrete, affecting close to a million homes across the UK and costing homeowners thousands in damages and removal costs.
But removing the plant is a serious challenge as it can only be killed in the ‘spraying window’, which is the time in between the plant flowering and the first frost.
Those working to destroy the knotweed on the River Roding are working against the clock but without the help of Government agencies such as DEFRA and the Environment Agency it seems time is running out.
‘We’re doing as much as we can but we have to stop whenever it rains and we only have two weeks left,’ explained Phil Sturgeon, a volunteer from Protect Earth, the charity helping the River Roding.
‘We’re spraying it with glyphosate which is controversial but it’s the only thing that works.
‘In September, the saps and sugars are going down into the plants roots and when we spray them the glyphosate hops on and goes down into the rhizomes.
‘This then kills the whole plant rather than just the stem, but it has to happen two or three weeks before frost.’
Mr Sturegon is helping kill the plant because his priority is combatting the climate crisis.
Pictured: Japanese knotweed growing along the River Roding – a nearby development is being built opposite
Pictured: Mr Powlesland a barrister at Lawyers for Nature and river guardian at the River Riding Trust
But he estimated that the entire affected area would cost hundreds of thousands of pounds to clear.
The river is surrounded by tidal reed, which absorb carbon, naturally filters sewage and is a fantastic habitat for birds and insects.
But the three-mile tidal section of the river is being overtaken by knotweed creating ‘dead space’.
‘We don’t know how the knotweed got there but you only need a tiny fragment to float in, lodge itself and then grow rapidly,’ Mr Powlesland a barrister at Lawyers for Nature told The Daily Mail.
‘When the tide comes up the knotweed breaks falls in and then grows elsewhere the whole river is affected and it will keep spreading.
‘Knotweed doesn’t support the area’s biodiversity so you might as well cover acres of the river in concrete.
‘It’s spreading all over network rail infrastructure and there will be an economic impact.’
Mr Powlesland added that Government intervention is the only way to rectify the dire situation.
He said: ‘The government needs to have a plan, map where the knotweed is and contain and remove it.
‘Across the country their plan is to let it grow out of control making it harder and more expensive to fix with every year that goes by.
‘In 10 years time there will be hundreds of knotweed patches it’s like watching a slow motion train crash and the government are just standing by and looking at it.’
Pictured: An aerial image of the River Roding surrounded by knotweed and reed beds near newbuild homes
Parts of the land the knotweed is growing on is owned by Transport for London and Network Rail and it is surrounded by the North Circular and multiple homes.
Mr Powlesland has already noticed the weed growing on railway tracks and has suggested it is only a matter of time before all of the surrounding infrastructure will be damaged.
However, local residents told The Daily Mail they had never even heard of Japanese knotweed.
‘I speak to people who live here everyday and they have no idea this is going on,’ Asif Noaman, the local postman said.
‘There are around 400 people that live on this estate and they need to be made aware of this, it’s absolutely terrifying.’
Resident Javed Iqbal added: ‘We moved here because we love the river, my twin girls play around here.
‘It’s ridiculous, we can’t afford to move anywhere else.
‘But I don’t see how a plant could do that.’
Pictured: A Japanese knotweed plant growing by the side of the River Roding
Japanese knotweed was introduced to the UK as an ornamental plant in the 19th century, it is identifiable by its hard, bamboo-like canes and distinctive shield-shaped bright green leaves which grow in a zigzag pattern along the stem.
It can devalue properties by around 10 per cent, but can totally destroy a property’s value in the worst cases where the plant is closer to buildings and more entrenched.
Emily Grant director of operations at Environet said the river edge is a good location for Japanese knotweed to spread.
Ms Grant has suggested the damage from miles of knotweed if treated professionally would cost hundreds of thousands of pounds.
‘The reality is a lot of areas are already too far gone, it would take a huge investment in order to bring it back around,’ she said.
‘If it does start encroaching onto private property then those property owners would be able to write to the land owner and if they failed to do anything they could bring a claim against them.
‘The thing with river systems is the rhizome system of the knotweed is broken off and carried along the watercourse and is deposited on the ground and starts growing in a new section.
‘In this location there is a huge threat to our nature and ecology because the knotweed is outcompeting all the natural plants that should be there, it has a huge environmental impact.’
A TfL spokesperson said: ‘We are aware that some of our land situated by the River Roding in East London has been affected by Japanese Knotweed and we are already undertaking measures to treat and control it.’
A Network Rail spokesperson said: ‘While we’re not currently aware of any specific issues raised, we’d be happy to investigate further if a specific location or concern is identified. We encourage anyone with information to get in touch so we can respond appropriately.’
The Daily Mail has contacted DEFRA and the Environment Agency for comment.
