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Cyffdy Himalayan Balsam Project

11 October 2016

Results of a research project into the success of different methods of controlling Himalayan Balsam. A blog written by the Llyn Tegid Foreshore Supervisor, Rhodri Dwyfor Parry.

Working as Llyn Tegid Foreshore Supervisor over the summer in 2015, I had the opportunity to assist the area wardens with projects controlling Himalayan Balsam plants – a widespread invasive species in Snowdonia.  In the meantime I’ve been studying for a masters degree in Sustainable Environmental Management at the University of Bangor, before returning to Llyn Tegid to work again this summer. I’ve been fortunate enough to combine my education with my work by conducting research for one of the National Park’s projects and my dissertation. The Llyn Tegid area wardens, Arwel Morris and Bill Taylor, have worked on a successful programme to eradicate Himalayan Balsam from the banks of Llyn Tegid’s tributaries since 2010, spending a number of laborious hours picking the plant by hand with the assistance of volunteers. This year they’ve been assessing the potential of two other methods of controlling Himalayan Balsam in an experiment at Cyffdy farm, Parc.  These were strimming, and spraying the plants with herbicide.

SNPA staff and a few volunteers

SNPA staff and some of the volunteers

Over four work days, 26 SNPA staff and Snowdonia Society volunteers assisted to clear the Himalayan Balsam from a 1.86 hectare area, through picking, strimming and spraying herbicide. My research has been assessing the success of each method, and comparing their cost effectiveness. By looking at the number of Himalayan Balsam plants growing 6 weeks after the work, we discovered that all three methods were successful and almost as good as each other. All methods removed over 99% of the Himalayan Balsam in the research areas.

The cost of strimming and spraying was estimated using a quote by contractors, and picking on the basis of volunteers doing the work.  Although strimming and spraying were more expensive than picking by hand, they were much quicker saving a number of working hours. The area wardens and volunteers spent 1,100 hours picking Himalayan Balsam between 2013 and 2016, and it is estimated that as much work could be done in approximately 39 hours by strimming or 34 hours by spraying, if the terrain and location were suitable.  Past research recommended hand picking as the best method of removing Himalayan Balsam on riversides and it allowed the wardens to make the best use of volunteers. However, it has been shown that on sites such as Cyffdy where the terrain and location is suitable, time could be saved in future by strimming and spraying, with similar results.

It is hoped that the results of my research will assist the National Park to maximise the effectiveness of their Himalayan Balsam control strategy in future, and cease any further spread of the plant for the benefit of our native biodiversity.

Thank you very much to everyone who assisted with the work, especially to Arwel Morris and Bill Taylor for arranging and assisting with the research.


SNPA staff strimming...


...and spraying

Picking by hand

Volunteers picking by hand