Health warnings over giant hogweed

Giant hogweed

Experts are warning parents, walkers and dog owners of the dangers of contact with giant hogweed, found along the banks of the Nunney Brook.

giant hogweed headlines
Giant hogweed horror stories have been making headlines.

Giant hogweedSix young children and a great dane were reported to have suffered severe burns and blisters after coming into contact with giant hogweed plants in 2015.

Tabloid headlines dubbed giant hogweed, which is widespread in the UK, “the most dangerous plant in Britain”.

Now the Property Care Association (PCA) has warned the invasive weed can pose a threat to public health as the plant’s sap is highly toxic to the skin in sunlight.

Heracleum mantegazzianum, commonly known as giant hogweed or wild parsnip, is a highly toxic plant that typically grows to heights of 6 metres (20 ft).

The sap of giant hogweed causes phytophotodermatitis in humans, resulting in blisters, long-lasting scars, and — if it comes in contact with eyes — blindness.

These serious reactions are due to the furocoumarin derivatives in the leaves, roots, stems, flowers and seeds of the plant.

Giant hogweed is native to the Caucasus Region and Central Asia. It was introduced to Britain as an ornamental plant in the 19th century, and it has also spread to many other parts of Europe, the United States and Canada.

nunney combe
Giant hogweed can be found at the far end of Nunney Combe.

In Nunney it grows along the banks of the Nunney Combe, near the footbridge towards Whatley. The area, on the opposite side of the riverbank from the path, is popular with walkers, children and dogs.


Giant hogweed is a highly invasive species that spreads like wildfire. Every flower contains 80,000 seeds that are easily dispersed.

Garden and land owners are warned that they have a legal duty to report giant hogweed to the Environment Agency, through their website called Plant Tracker. They should also report it to their local authority.

The law was changed a few years ago so that giant hogweed is now covered under ASBO legislation.

Local authorities who find the plant growing on a person’s land can give them a fixed penalty fine of £100.
If this order is ignored, individuals can be fined up to £5,000 and organisations can be fined £20,000.

Although over-the-counter weedkillers, like Round Up, are effective against giant hogweed, it is important that the plants are safely removed by specialists.


giant hogweedThe plant’s large umbrella-shaped flower heads make them attractive for young children to play with and the thick, hollow stems make great pea shooters, apparently.

Children have been playing with giant hogweed for over a century – and apparently without making newspaper headlines.

But experts warn that even a casual brush against the plants can cause severe pain and burns in some people and animals. Because the plant is phototoxic, the effects can be worse on bright, sunny days too.

Within 24 to 48 hours, rashes, burns and blisters may begin to appear. The toxins affect almost everyone but children are particularly sensitive.

Victims of the plant are known to suffer skin rashes and blisters that are sensitive to light for up to seven years.

giant hogweedParents and dog owners are advised to take extra care if they live near places with giant hogweed. Children should be made aware of the dangers of touching the giant plants.

If anyone comes into contact with giant hogweed, the advice is to rinse the affected skin with soap and cold water and cover it up to prevent sunlight causing blisters.

They should contact a GP, A&E department or vet if anyone suffers effects within 24 to 48 hours after coming into contact with the plants.

giant hogweed headlines

The GB Non-Native Species Secretariat has a useful factsheet that you can download for more pictures and information.