Volunteers have been waging war on an invasive weed which has been choking plants on the edges of the River Wensum, making the banks more susceptible to erosion.

Norwich Evening News: Himalayan balsam overshadows other plants, smothering them to death. Photo: Brittany WoodmanHimalayan balsam overshadows other plants, smothering them to death. Photo: Brittany Woodman (Image: Archant)

Members of the Norwich RiverCare group spent Saturday morning tearing up Himalayan balsam plants which have been growing on the river's banks in the Marlpit area of Norwich.

The problematic plant's pretty pink flowers belie the weed's destructive nature.

It can grow well above head height and smothers other vegetation, killing off other plants.

A non-native invasive species, it was introduced to the UK in 1839 and the fast-growing plant is a particular problem on riverbanks.

Norwich Evening News: Norwich RiverCare volunteers hacked back the invasive Himalayan balsam on the banks of the River Wensum. Organiser Stuart Stebbens and volunteers. Photo: Brittany WoodmanNorwich RiverCare volunteers hacked back the invasive Himalayan balsam on the banks of the River Wensum. Organiser Stuart Stebbens and volunteers. Photo: Brittany Woodman (Image: Archant)

Stuart Stebbens, who co-ordinates the volunteers for the Norwich RiverCare group - a Keep Britain Tidy project supported by Anglia Water - said the weed was "a big pain".

He said: "Himalayan balsam is an invasive species, which was brought over from India to go in Victorian gardens, but has now become a real problem because it loves river banks.

"Because it grows so well, it shuts out all the other plants beneath it. They end up dying and then you have a monoculture of just one species.

"And when it dies back in the winter, you're left with just brown earth beneath where it was which increases surface run-off and erosion."

Volunteers met at Marlpit Community Centre on Saturday morning and went out on a 'balsam bash' to uproot the plant before it flowers, giving other plants the chance to thrive on the Wensum's banks.

The group also did a litter pick and built a wildlife raft. Mr Stebbens explained: "That sits in the river with a clay pad in the middle and then any mammals which cross it will leave the footprints in it, so we have a better idea of what is living in and around the river.

"Last year we had one in for three months and we were pleased to see we had an otter in the river. We'll be looking to see if that is still around, while it will also be useful in establishing how many mink are in the area."

The Norwich RiverCare volunteer group, which was formed in 2017. Anyone interested in getting involved should email stuart-norwichrivercare@outlook.com