Otherwise known as Heracleum mantegazzianum is a large member of the carrot family and is native to Eastern Europe. The plant was introduced to the UK for ornamental purposes and is typically found near watercourses, damp meadows and on waste ground. The plant is a close relative of cow parsley and can easily be mistaken as common hogweed, except it grows to a much larger five metres tall and is capable of producing approximately 50,000 seeds.
WHAT MAKES THIS PLANT SO BAD?
It is considered an ‘invasive’ plant and are a non-native species that can cause harm to the environment and to human health. In this plants case, if the sap comes into contact with the skin it can cause severe burns and cause an increased sensitivity to sunlight.
The sap contains toxic components and is found in the leaves, roots, flowers and seeds, which even brushing against can transfer to the skin causing irritation and in severe cases significant blistering that occurs within a 48-hour time period. Such blisters heal slowly and can be extremely painful which can develop into Lime Disease making the skin hypersensitive to ultraviolet light. In severe cases, if this sap comes into contact with eyes it can cause blindness.
WHAT HAPPENS IF YOU COME INTO CONTACT WITH THE PLANT?
If you come into direct contact with the plant wash the affected area of skin thoroughly with soap and cold water, and cover it up, avoiding direct sunlight for 48 hours. Seek medical attention if any reaction occurs.
Chemical or physical treatments are the two most conventional techniques for controlling Giant Hogweed. Chemical treatment is carried out by either spraying or injecting the stems with a Glyphosate based solution. Alternatively, the plant can be controlled physically by regular cutting to ground level; this will need to be done at least 6 times a year. Appropriate protection should be worn when handling the plant in order to prevent a reaction.
THE LAW ON INVASIVE NON-NATIVE PLANTS
It is an offence to grow or dump invasive plants in local streams or woodlands under Schedule 9 of the Wildlife and Countryside Act 1981. The government prohibits the sale of such species and anyone caught doing so will face a government implemented penalty. Note that growing controlled plants is considered to be a criminal offence which carries a fine of up to £5,000 and/or 2 years of imprisonment.
Because of the law, people are encouraged to follow strict guidelines to help eradicate these plant species. The formation of the Global Invasive Species Programme in 1997, conceptualised strategies on how to eradicate them which was published in 2001.