Giant hogweed is a dangerous weed / Farbenfreude/Wikimedia Commons

The giant hogweed is often found on river banks

As families venture outside to enjoy the summer sunshine, several reports have emerged of children being severely burnt after touching the giant hogweed plant.

But what makes it toxic, and what should you do if you touch it?

What does giant hogweed look like?

Also known as heracleum mantegazzianum, the giant hogweed has long, green stems which branch out into clusters of small white flowers. It is therefore sometimes confused with the common hogweed, cow parsley, elderflower, or bishop’s lace.

However, it is set apart by its purple-hued stem, thin spines and leaf stalks covered in spots.

The plants can grow up to 3.5m (11.5ft) high and can span around 1m (3.5ft). The flower heads can be as large as 60cm (2ft) across.

Where is it from?

The giant hogweed was brought to the UK from Central Asia in 1893, and is now a common sight on river banks, canal towpaths, woodland and heathland.

What does it do to you?

Chemicals in the plant cause photodermatitis, which makes the skin sensitive to sunlight and other sources of ultraviolet light. It can therefore cause skin to blister or become pigmented, causing long-lasting scars, according to the Royal Horticultural Society.

Simply brushing against or touching the plant is enough to release the sap, and can cause serious burns within around 24 hours. If the sap comes into contact with the eyes, it can cause temporary or permanent blindness.

Blistering can re-occur for many years.


What do I do if I touch a giant hogweed?

The NHS advises covering the area and washing it with soap and water. If you feel unwell after contact with giant hogweed, speak to your doctor.