Tamar Valley Invasive Species Project

The Tamar Invasives Group was created specifically to control invasive plants in the River Tamar corridor. The partnership of four organisations, Tamar Valley AONB, Environment Agency, Natural England and Cornwall Council, have been working together for the past 15 years to control invasive species in the riparian section of the AONB. The three main species are Giant Hogweed, Japanese knotweed and Himalayan balsam.

The main focus has been on the eradication of Giant Hogweed and the project has demonstrated considerable success by maintaining focus over this time. This has been achieved by surveying and control (herbicide treatment or hand digging on organic land).

Further funding  and support from South West Water, Environment Agency, Natural England and the Tamar Valley Area of Outstanding Natural Beauty (TVAONB) has allowed the group to continue with the treatment for the forthcoming season.

Treatment will be starting in the next few weeks and builds on a partnership that has been tackling this problem for over 15 years.  Giant Hogweed is now showing a significant decrease in the Tamar Catchment and the Tamar Invasives Group think with the continued and ongoing support of the landowners that within a decade we should be able to eradicate this pernicious plant.

Counts from the contractors carrying out the removal work suggests the number of Giant Hogweed plants in the Tamar for 2017 is 297 plants – down from c3,658 in 2012.

Below is some before and after treatment photos which highlight the excellent work undertaken by the Tamar Group.