Giant hogweed Lancashire: Warning over UK's 'most dangerous plant' as interactive map shows where it grows in the county

People are being warned to be extra vigilant after a four-year-old girl in the North West was left with second-degree burns after touching ‘Britain’s most dangerous plant’ - the toxic giant hogweed.

By Jon Peake
Wednesday, 15th June 2022, 11:12 am
Updated Thursday, 16th June 2022, 10:48 am

Giant hogweed is a fast-growing invasive plant. It mainly grows next to water, in damp meadows or on derelict land. It grows exclusively by seeds, which can be planted deliberately or carried by wind or water. It can cause harm to humans and animals and although not native to the UK, it is now widespread.

Now, WhatShed has produced a live interactive map to track the spread of the plant.

Just last year, a council in Lancashire estimated that there were around 70 knotweed sites in the area and a massive mapping operation began and will continue throughout 2022.

The interactive map showing locations of the weed in Lancashire

You can report an area containing the invasive weed on the Lancashire County Council website here.

Here’s everything you need to know about giant hogweed

Giant hogweed (Heracleum mantegazzianum) is a close relative to cow parsley.

It has thick bristly stems and can reach over 3m (10ft) in height.

Dangerous - giant hogweed can cause serious blisters and burns

The flowers are white and held in flat-topped clusters that can be as large as 60cm (2ft) across.

Giant hogweed was originally brought to Britain from Central Asia in 1893.

Its leaves, stems, roots, flowers and seeds contain toxic components which can be transferred by contact and make exposed skin extremely sensitive to sunlight.

A red rash develops on the skin, which grows more painful and then blisters.

What to do if you come into contact with it

If the sap of the giant hogweed comes into contact with your skin, it can cause severe, painful burns and make your skin sensitive to strong sunlight.

If you touch a giant hogweed, cover the affected area, and wash it with soap and water.

The blisters heal very slowly and can develop into phytophotodermatitis, a type of skin rash which flares up in sunlight. If you feel unwell after contact with giant hogweed, speak to your doctor.

What to do if it is growing on your land

If the weed is growing on your land, you should aim to treat the plant as early as possible to stop it from spreading and becoming a problem to neighbouring land.

Due to the dangerous nature of the plant it is not recommended you treat it yourself. Use a specialist company, as they will be skilled at control and can dispose of the plant waste safely.

You should never dispose of Hogweed in your household, business or green waste collection.