Looming threat of 'UK's most dangerous plant' 

An online map shows giant hogweed is mostly spotted across Scotland’s Central Belt, the North East and in the Highlands around Inverness, and is thankfully rarer on the West Coast.

But in August 2019, a popular common ground in Soroba, Oban, was declared a no-go area after four people were treated for burns from the plant, with one attending A&E. Worst affected was a man who volunteered to cut grass there, only to find his skin covered in a rash and blisters.

After two concurrent mild and wet springs, experts warn weather patterns are creating an opportunity for it to thrive and gain ground. “That means there is more chance of people being exposed to it," explained the Property Care Association (PCA), which has an identification guide on its website.

Typically 2-4m tall, giant hogweed has a stem measuring up to 10cm in diameter, and a large, white, umbrella shaped flowering head up to 80 cm across. Its leaves, which are sharply serrated or divided, can reach up to two metres in width, while the stem is usually covered in sharp bristles and has blotchy purple markings.

“If you do come in to contact with the plant, you must cover the affected area to block sunlight then thoroughly wash the area to remove the sap," explains the NHS. "Should redness or blistering occur, you should seek medical help.”

Healthline adds: “Skin irritation that’s caught early might be treated with a steroid cream and nonsteroidal anti-inflammatory drugs, such as ibuprofen, to relieve pain. Severe burns could require surgery to graft new skin over the damaged skin.”

There is no legal requirement to control it, though it is an offence to cause this species to grow in the wild. The owner of the land on which the plant is present has responsibility for it. Anyone who spots it growing on amenity land, such as parks, playing fields, footpaths or road verges, should report it to the local authority.

It can be very tricky to eradicate, because each plant produces over 50,000 seeds, which can live in the soil for up to five years. The Royal Horticultural Society warns people to protect themselves from any skin contact with the sap, especially on the face, when managing the plant.

Chemical spraying is the best method of dealing with it, during the growing season from March to August, before the plant flowers and seeds. Strimmers and chippers should not be used, as this can cause sap to become airborne, resulting in injury if it contacts the skin.