Physical control

There are a number of approaches to physically control an invasive plant species. These can range from mechanical excavation or hand removal to the installation of growth barriers to suppress or stop invasive plants encroaching on to a site. A summary of these methods is provided below:


  • In circumstances where access to the infested area is needed within a relatively short space of time (e.g. for construction activities), it may be appropriate to excavate the infected soils for removal to another part of the site for treatment or for off-site disposal at a licensed landfill site.


  • Strimming: can be an effective method of control for certain species, such as Himalayan balsam, but only if applied to young plants before the seed heads have developed (typically Mid June). Himalayan balsam should not be strimmed before Mid May otherwise it will regenerate.
    • It is unlikely that strimming will be effective against a woody species such as Rhododendron, as it will have little effect on root growth.
    • Giant hogweed should not be strimmed, as this is likely to result in sap being sprayed on the operator and anyone else in the vicinity, potentially resulting in severe burning to exposed skin.
    • This method is also not appropriate for Japanese knotweed as it will result in plant fragments being dispersed over a wide area and will only serve to exacerbate the problem.
Invasive Species Northern Ireland

Invasive Species Northern Ireland