A TEENAGER who saw her local riverbanks overtaken by a giant alien weed is waging war on the invading plant.

Alaina Harrison became concerned after noticing Himalayan Balsam, which can grow up to three metres tall, taking over the banks of the River Deerness near her home in Esh Winning and smothering all other life in its path.

Now the 18-year-old is recruiting villagers to take part in “Balsam Bashes” to uproot the alien invader so other plants have a chance of survival.

She said: “I’ve lived around here for the past five years and I’ve watched it spread all the way from Durham to our village.

“I loved seeing the British wildflowers and blackberries, but you don’t see them anymore because the whole riverbank has been taken over by Himalayan Balsam.”

With help from the charity Fixers, which helps young people campaign on issues which matter to them, she has organised a number of events to halt the spread of the plant.

Introduced as a greenhouse plant in Britain in 1839, Himalayan Balsam soon escaped into the wild and grows at a fearsome speed.

Each produces an average of 800 seeds, which can be fired 20ft from its stem, allowing it to spread quicker than native plants.