The PlantTracker project is a collaboration between the Environment Agency, the NatureLocator team at the University of Bristol and the Centre for Ecology and Hydrology. The project kindly provides us data with locations of himalayan balsam for our Known presence map. You can also report and view maps of other invasive non-native plant species on their website.
Non native species secretariat
This is an excellent source of information. It has a map showing current projects going on around the UK, making it easy to find projects near you, or of a similar nature to yours. This also lists the contacts for each project, so you can get in touch and get ideas.
It also has a very good set of identification sheets, and photographs.
The Cornwall Knotweed Forum
This page has a leaflet that can be printed off, as well as a useful short guide to control, and pictures. The information on Japanese Knotweed is a little more in-depth than the Himalayan Balsam information, but it is still well wroth checking out.
The Environment Agency
This webpage gives you information on how to control invasive plant species, and also gives you the link you need to applying for permission to use herbicides near water. Please note you need to apply at least 3 weeks before spraying.
The countryside agencies in the UK may be aware of invasive species control projects going on in your local area, and it may be worth contacting them.
Invasive Species Ireland
This website gives some advice on managing invasive species, what you can do to help minimise the spread, and also gives you an option to map the presence of invasives in Ireland.