Volunteers and satutory organations have been working together to erradicate Himalayan Balsam and Giant Hogweed from a number of tributaries of the Colne this year.

Sandy Belloni, Director of Community Connections Projects CIC and Adam Buckland of the Environment Agency have been working to clear the Radlett Brook digging out over 200 plants in two walkovers of the Brook so far this year.  On the Misbourne two large stands of this invasive weed are being controlled by the Chilterns Chalk Streams Project, working with landowners and volunteers. So far this work has resulted in the clearance of nearly 200 plants in three sessions, representing about 75% of the total number of plants present. Further work parties are planned in July and August.

Giant Hogweed, as the name suggests is a very large plant that can grow to 5m high. Originally introduced to the UK in the 19th century, giant hogweed has spread rapidly in the wild, growing on riverbanks and damp ground. It produces large umbels of white flowers from which it produces 30 to 50,000 viable seeds per year. The sap of giant hogweed contains a toxic chemical which sensitises the skin and leads to severe blistering when exposed to sunlight. As a result it is really important that this pernicious weed is erradicated.

The Chilterns Chalk Streams Project has also been working with local volunteers, this year, to control two very large stands of another invasive non-native plant - himalayan balsam - along the R. Gade and the R. Misbourne. Large stands of this plant have become established close to the sources of each river and threaten to spread downstream if not controlled. Control of the stand on the Gade at Great Gaddesden is now in its third year and is close to being erradicated.  Work to clear himalayan balsam from the Misbourne is in its first year with two work parties having been carried out so far and another three events plant in the coming months. 

If you would like to take part in any of the balsam pulling events on the Misbourne and Gade, please contact the Ceri Groves This email address is being protected from spambots. You need JavaScript enabled to view it. 

Design by LTD Design Consultants and build by Garganey Consulting. From an original concept by the Herts and Middlesex Wildlife Trust.