Invasive Plants

Under the ‘Wildlife and Countryside Act 1981’ landowners are legally responsible for the prevention of the spread of some invasive species such as Japanese Knotweed and Giant Hogweed. Other invasive species such as Himalayan Balsam along with Common Ragwort can cause ecological problems and, in the case of Common Ragwort, is toxic to horses and other farm animals. Morelia Ecology is able to identify invasive plant species and suggest effective control methods.

Japanese Knotweed

Japanese Knotweed is perhaps the most invasive of the introduced plant species. It originates from the Far East and was a popular ornamental garden species that was first cultivated, in the UK, in Victorian times.

Japanese Knotweed causes ecological problems by out competing native plant species and can cause structural damage to buildings. It is very prolific and spreads via rhizomes and cut stems (both of which make it difficult to control).

Giant Hogweed

Giant Hogweed is another invasive plant species that is covered by the Wildlife and Countryside Act 1981, under the Act it is an offence to ‘plant or otherwise cause Giant Hogweed to grow’ in the wild. Anti-Social Behaviour Orders have been used to compel land owners to remove Giant Hogweed. Giant Hogweed is a perennial which originated from South-west Asia. It can attain a height of 3.5m with leaves of up to 1m in length and stems that are 10cm thick, a true giant! Giant Hogweed causes ecological problems by out competing native species and can also cause serious skin blistering.

Himalayan Balsam

Himalayan Balsam, another invasive species, was introduced into the UK in 1839. This alien species reduces the native plant diversity by forming dense stands that tend to shade out other species. This species is now seen regularly on the banks of rivers and streams. Himalayan Balsam is listed on 'Schedule 9' of the 'Wildlife and Countryside Act 1981' this makes it an offence to 'plant or otherwise allow to grow in the wild'.

Common Ragwort

Common Ragwort contains toxic pyrrolizidine alkaloids; these are known to cause liver damage in grazing animals. It is important that horse owners and land owners are able to recognise this plant. Common Ragwort is covered by the 'Weeds Act 1959' which requires land owners to control this plant in 'high risk' areas. Common Ragwort is a native plant which supports pollinating insects so its removal from all areas is not recommended or desirable.