ILKLEY residents are looking for more hands to help remove an invasive weed from the banks of the River Wharfe and its tributaries.

Himalayan balsam (Impatiens glandulifera), also known as policeman’s helmet, is an attractive plant introduced to the UK in 1839. Since then it has spread throughout the country especially along rivers and streams.

It tolerates low light levels and also shades out other vegetation, so gradually impoverishing habitats by killing off other plants.

It is an annual, growing from seed each year at an astonishing rate to reach a height of two or even three metres.

Between June and October it produces clusters of purplish pink (or rarely white) helmet-shaped flowers. The flowers are followed by seed pods that open explosively when ripe.

Each plant can produce up to 800 seeds. These are dispersed widely as the ripe seedpods shoot their seeds up to seven metres (22ft) away.

It dies down over winter leaving bare soil which may then be at risk of erosion when river levels rise.

Volunteers, including members of Climate Action Ilkley, Ilkley Clean River Group and Wharfedale Naturalists, have decided to tackle the large number of plants around and downstream of the suspension bridge in Ilkley and particularly on Beanlands Island.

The plants can very easily be pulled up, and if already in bloom the flowers can be pinched off and bagged to prevent seeding.

The plants can then be very satisfyingly scrunched underfoot so they don’t continue to flower.

A start was made on Monday evening but there is lots more to do, and it is urgent before the flowers set seed.

All hands would be welcome on Monday, July 27, 6.45pm for 7pm at the suspension bridge.