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Invasive plants


Cornwall's ecology and landscape is of national and international importance. Twenty-seven per cent of the county is designated an Area of Outstanding Natural Beauty (AONB) and a further 24% as Area of Great Landscape Value (AGLV). Invasive plants threaten the native flora that is integral to the beauty of our countryside.

What makes an invasive plant?

Cornwall's landscape is highly managed. Our increased interest in gardening and exotic plants over the last 200 years has led to a great number of new species being introduced. Many have made Cornish gardens the envy of the world. But some species have made themselves at home and have become invasive. In their native home these plants may be well behaved due to different growing conditions. However, in the Cornish climate they have spread over the garden hedge and into the countryside. In some areas our native flora is being overtaken by these plants. Cornwall is currently pioneering work in the control of invasive alien weeds such as Japanese knotweed. There are also a few problematic native invasive weeds, such as common Ragwort. They require careful and co-ordinated management to limit their spread.

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Stop invasive non-native plants from spreading

Invasive plants

Common Ragwort

Common Ragwort grows up to a metre tall with flat clusters of bright yellow daisy-like flowers in summer. All parts of the plant are poisonous.

Giant Hogweed

Giant Hogweed is a large member of the carrot family. It is generally found near watercourses, in damp meadows and on waste ground.

Himalayan Balsam

Himalayan or Indian Balsam is most commonly found on riverbanks and damp areas, though it is capable of thriving in many other habitats.

Japanese knotweed

Japanese knotweed is found on roadsides, riverbanks and derelict land. It prevents our native plants from growing and causes structural damage.

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