The presence of invasive species, particularly a number of non-native plant species, has become a serious concern over the past twenty years. These species can bring a whole range of problems including damaging concrete, tarmac and brickwork, causing health problems for grazing animals, irritation and blistering of skin and damage to local ecosystems.
The most commonly recorded problem species are Japanese knotweed (.pdf, 222Kb), Giant Hogweed, Himalayan balsam and Common Ragwort (.pdf, 523Kb).
Japanese knotweed can damage concrete, tarmac and brickwork as well as having a major impact on biodiversity. It spreads by its underground roots (rhizomes) and a piece of the root as small as 10mm can produce new plants.
Giant Hogweed can grow up to 5m tall. The stem and leaves have small hairs coated in sap that cause severe skin irritation and blistering.
Himalayan balsam has a major impact on biodiversity as it forms dense stands that shade out other vegetation. It is very common along watercourses where its seeds are easily spread.
Common Ragwort is important for biodiversity but is a problem where it grows on or near grazing land as it can be toxic to grazing animals when eaten. DEFRA have produced a Code of Practice for dealing with Common Ragwort and are the best contact for specialist advice.
Who is responsible for dealing with invasive species?
It is up to individual landowners to carry out treatment of invasive weeds on their land. The Council and the Environment Agency are not responsible for the control of invasive species on behalf of other landowners and do not have any powers to force landowners to carry out control.
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