THE fight has begun against a damaging invasion of alien plants attacking the Lake District.

Japanese knotweed and Himalayan balsam have now reached such epidemic levels, agencies and volunteers joined forces to tackle the species introduced to Britain by green-fingered Victorian garden enthusiasts.

A group of people, equipped with gardening gloves, have begun to eradicate the native Indian balsam (found in the western Himalayas) around Glenridding, Lake District National Park Authority ranger Colin Eastham explained the plant, introduced to Britain in 1839, had colonised riverbanks and damp ground, competing with native plants and causing erosion.

"It is three metres high and produces explosive seed pods that can scatter over long distances. One plant can produce up to 40,000 seeds," said Colin.

"Chemical spraying in environmentally-sensitive areas has been ruled out, leaving good old fashioned pulling as the best clearing option."

The Lake District National Park Authority, Environment Agency, English Nature, Cumbria County Council, National Trust and Eden Rivers Trust are working to get to the root of the problem and encouraging help from individuals and landowners.

Japanese knotweed is the other scourge causing serious problems on roadsides, riverbanks, lakeshore and derelict land. Around three metres tall, with a root system spanning seven metres, the shrub displaces native flora and causes structural damage.

Regular knotweed cutting, digging up under a special waste licence, and herbicide spraying by approved operators are all included in the action plan.

Fourteen different sites in the Ullswater valley have been tackled so far this year.