New Techniques to control Himalayan Balsam

Posted by Sara King BSc (Hons) MCIEEM on 27/08/2014

Himalayan Balsam is a non-native invasive species, and is commonly found along river banks and watercourses. The species is listed in Schedule 9 of the Wildlife and Countryside Act 1981, under which it is an offence to plant or otherwise cause to grow the plant in the wild. The species spreads quickly on sites as it out-competes native wildlife and spreads rapidly.  The plant spreads using its seed pods, which explode when touched scattering seeds up to 7m away.  Seeds are also spread by water and may remain viable within the soil for up to two years (Environment Agency, 2010). 

Current techniques to control Himalayan balsam can be costly and labour intensive. These include chemical treatment or manual removal through pulling. The species should be treated before seedpods form and disperse.

New techniques to control this species, including biological control, are currently being developed to reduce the spread of this damaging species. Defra have been investigating the potential use of introducing ‘natural enemies’ into the UK to control the spread of this species. These exist in Himalayan balsam’s native habitat. An Indian fungus is currently being tested to check that the introduction of this fungas will not affect UK ecosystems. Currently, the potential impacts from the introduction of this species appears to be minimal, and if introduced to the UK is likely to have a significant benefit in the fight to control Himalayan balsam and minimise costs to developers and statutory bodies.