Giant hogweed labeled UK's most dangerous plant - how to spot it in your garden

Giant hogweed is an invasive plant that can cause severe burns and blistering.

The invasive plant has made headlines as it has left a four-year-old hospitalised with second degree burns.

With dangerous sap, people may be concerned about the plant and its toxic effects.

Those who want to keep away from Britain's 'most dangerous plant' will first have to get an understanding of what it looks like, as well as its dangers, says the Mirror.

Here are all the key facts around giant hogweed, including where you may find it and what you can do if you come into contact with its harmful sap.

Giant hogweed is an herb related to carrots, cilantro, and parsley, which grows naturally in the Caucasus Mountains, stretching between the Black and Caspian Seas in south west Asia.

Due to its large size and delicate-looking white flowers, the plant was first introduced to the United States for decorative purposes.

Despite its attractive appearance, giant hogweeds soon became an invasive and dangerous plant species, which is harmful to both humans and the natural habitat.

Is it dangerous to touch giant hogweed?

Giant hogweed isn't dangerous as long as you don't touch its sap. The sap inside the stalks contains a toxic chemical called furanocoumarin, which is what causes burns.

When the sap comes into contact with our skin, it causes a reaction called phytophotodermatitis, which damages your DNA and changes the way your skin protects itself from UV light.

This means your skin isn't able to protect itself properly from the sun, so if exposed to sunlight your skin will develop severe burns.

The chemical reaction can happen within 15 minutes of your skin coming into contact with the sap, with redness and blisters typically developing 48 hours after exposure.

The longer the sap remains on the skin, the worse it will react to sunlight.

How severe the burns are will depend on how long you've been in the sun for, and there are chances that your skin is still affected for months after exposure.

The sap from giant hogweed can damage more than the skin. If it gets into our eyes, it can cause temporary or even permanent blindness.

Breathing in particles of the plant from the air can also result in respiratory problems.

What does giant hogweed look like?

Giant hogweed is usually 15 to 20 feet tall when it's fully grown. The plant grows very large and spreads very quickly, crowding out other plants near it

Before growing fully, it can be easy to confuse it with harmless plants like Queen Anne’s lace, which also has clusters of small white flowers.

The easiest way to recognise giant hogweed is by looking at the stem, which will be quite thick - about two to four inches wide - and have dark purple-red blotches and thin, white bristles.

Leaves of the plant will be green, jagged and as large as five feet wide. The leaves may also have thin, white bristles.

The most dangerous part of the giant hogweed is its sap, which is located in the long hollow stem and the stalks that attach the leaves to the plant.

So, it's important to be careful when cutting the stem or tearing the leaves off giant hogweed. The sap can also be found in the roots, seeds and flowers.

Where is giant hogweed found in Scotland?

Giant hogweed has been found in a number of Scottish cities, most notably including Glasgow and Edinburgh.

They have been known to grow around rivers, and in 2020 they spread across a number of Scottish riverbanks during the lockdowns.

The invasive plant spreading is a concern in Scotland as it is notably difficult to get rid of according to the Forth Rivers Trust.

Alison Baker, from the trust, said to the BBC : "Giant hogweed seeds will last up to 20 years, they are almost indestructible. And once they are in the environment it is almost impossible to get rid of them."

What to do if you touch giant hogweed sap

If you get giant hogweed sap on your skin, wash the area with mild soap and cool water as soon as you can. The faster you can wash off the sap, the less damage it will cause.

Make sure to keep the skin covered when you're outside to protect from the sunlight.

If rashes or blisters start to form, seek medical attention. The treatment will depend on how severe the burn or reaction is.

In case it's caught early, the skin irritation may be treated with a steroid cream and non-steroidal anti-inflammatory drugs like ibuprofen to relieve pain.

However, severe burns might require surgery to graft new skin over the damaged area. Besides keeping your skin covered, it would be wise to wrap any blistered areas with gauze to prevent more sun exposure - continue to do this even after blisters are healed.

Seek medical attention immediately if the sap has got into your eyes.

Don't miss the latest news from around Scotland and beyond - Sign up to our daily newsletter .