Giant Hogweed

Giant hogweed growing on waste ground in the UK.

What is Giant Hogweed?

Giant Hogweed (Heracleum Mantegazzianum) is an invasive and highly toxic plant that has severe safety issues when in close contact with humans and animals. It was introduced as an ornamental plant by the Victorians.

Its appearance is similar to cow parsley but on an enormous scale, growing up to 6 metres in height. Foliage creates a dense canopy over surrounding land, smothering native flora and seriously affecting biodiversity. Giant Hogweed thrives beside watercourses, causing erosion of riverbanks.

Giant Hogweed removal solutions

TCM offer a range of Giant Hogweed removal solutions and management plans for residential customers and commercial businesses.  If you are home or land owner who is concerned about the presence of Giant Hogweed at your site, get in touch with TCM to discuss be most appropriate treatment option for location.

Why is Giant Hogweed a problem in the UK and Ireland?

The watery sap of the plant contains harmful toxins (known as furanocoumarins) that cause photo-dermatitis and can cause blindness. After exposure to sunlight, painful blistering occurs where the sap has come into contact with skin. The effects may not become apparent for up to 48 hours after contact with the sap/stem but a reaction may also occur within just 15 minutes of contact. 

Prior to coming into contact with Giant Hogweed:

  • Always wear non-porous gauntlet gloves when examining the plant
  • Wear long-sleeved, long-legged garments
  • Use goggles, particularly when undertaking clearance work
  • Remember that even the dead stems can give a nasty burn

Should you come into contact with Giant Hogweed:

  • Immediately wash the area of skin thoroughly with water
  • Protect the area from exposure to direct sunlight by covering with clothing, bandaging etc.
  • Seek medical advice

Giant Hogweed and the Law

  • Wildlife and Countryside Act (1981)

  • Environmental Protection Act (1990)

  • Anti-Social Behaviour, Crime and Policing Act (2014)


What does Giant Hogweed look like?  Take a look at our image gallery to identify Giant Hogweed.


Contact Us

Need Some Guidance?



TCM supply eradication solutions for homeowner. If you have Japanese Knotweed on your land, or your buyer’s mortgage has been refused - we can help. Contact us today.



TCM deliver science based knotweed removal solutions to a wide range of industries and organisations including construction, rail, road, the London Overground, property developers, local councils and more.

Howard Downer


Howard Downer, AKA Dr. Knotweed, has over 20 years of experience as an Environmental Consultant and is regarded by his peers as one of the most knowledgeable people in the Japanese knotweed industry.

Follow Dr. Knotweed to hear about the latest developments regarding Japanese knotweed and the implications of infestation.

Latest Residential Case Studies

Latest Commercial Case Studies

Need Some Guidance?