By Sue Crawford

Last updated at 08:31, Friday, 16 November 2012

A prolific alien invader is being banished from the Cumbrian countryside.

More than 15 miles of river bank and lake shore have been cleared of Himalayan balsam over the past year.

An army of volunteers has been out eradicating the plant, which spreads rapidly and can cause severe riverbank erosion.

Around 260 people have taken part so far this year in clearance operations in the Eden river system around the Penrith and Ullswater areas

Paul Greaves, invasive species officer at Eden Rivers Trust, said the clearance took place during 33 events, with volunteers contributing 1, 200 hours of hard work.

He added: “We are so grateful to all the volunteers for the fantastic contribution they have made towards ridding the Eden river system of Himalayan balsam. There is a lot more to do but we have made great strides forward this year.”

The project has been supported financially by the Environment Agency, Natural England, Cumbria Community Foundation and the county council.

Himalayan balsam was introduced to Kew Gardens from Kashmir in 1839 and has since spread out of control across Britain.

It not only shades out native plants, stopping them from growing, but also makes the banks liable to severe erosion in the winter when the plant dies down and leaves bare sections of ground with no protection.

Before dying down for the year its seeds spread over a large distance, allowing it to grow back quickly in the spring. The only ways to stop it are to pull out each plant by hand, strim the area or use a chemical spray.

As well as Himalayan balsam, steps have been taken to stop another major invader this year.

Another foreign plant, Japanese knotweed, has been spreading like wildfire. It is so tough it can grow through tarmac and concrete and once again takes over entire river banks, killing off native plants.

This year all the Japanese knotweed around Ullswater has been mapped and 98 per cent of it has been treated with herbicide.

First published at 08:14, Friday, 16 November 2012
Published by http://www.cumberlandnews.co.uk