Looking for HB

The Himalayan balsam-bashing group I volunteer with has done tremendous work over the last 10+ years to reduce the amount of balsam around Kendal and the river Kent.  This year the work is being coordinated by the South Cumbria Rivers Trust and also includes any balsam which is invading the river Leven and its tributaries.  This afternoon we quickly cleared a roadside verge in Troutbeck, but were horrified to see how much HB there is around the edges of fields and streams that join to flow into lake Windermere.