Giant Hogweed (Heracleum mantegazzianum) is a large member of the carrot family. It was brought to the UK as an ornamental plant from south eastern Europe. It is generally found near watercourses and in damp meadows, and it can also be found on waste ground. It is highly invasive. Each plant can produce up to 50,000 seeds which can survive for up to 15 years.
Contact with cut plant material in sunlight produces a skin reaction in almost all cases. Blisters occur 24 to 48 hours after exposure, and dense colour change to the skin is visible after three to five days. Damaged skin will also heal very slowly. Contact can also develop into phytophotodermatitis. This is a type of skin condition that flares up in sunlight and for which there is no straightforward treatment. Cut stems and leaves remain active for several hours.
Giant Hogweed is capable of growing to a height of up to 5 metres (15 feet). It should not be confused with our native common hogweed (Heracleum sphondylium) which is much smaller (generally less than 2m tall) and causes few problems.
Find out more
Download our Giant hogweed - guidance and control leaflet to find out more including:
- what it looks like
- what you should do if you see it and how it can be treated
- who to contact if you need more guidance or see hogweed growing on other property
- what our native common hogweed (Heracleum sphondylium) looks like
