Warm weather is causing giant hogweed havoc across the UK – with the dangerous plant creeping into gardens, riverbanks and parks.
A common issue in spring and summer, giant hogweed has been regarded as 'the most dangerous plant in the UK' because the plant's sap can cause severe skin burns.
Giant hogweed (Heracleum mantegazzianum), introduced into Britain and Europe from the Caucasus Mountains in the 19th Century, spreads by seeds and can reach over 3 metres (10 ft) in height.
But the invasive plant is growing out of control. Guy Barter, chief horticulturist at the Royal Horticultural Society (RHS), told The Times that recent flooding may have carried seeds to new locations.
Experts have issued a warning for how gardeners and households can look out for this plant, which is often mistaken for cow parsley, as the biggest problem is that it can easily blend into any planting scheme.
What does giant hogweed look like?
'Deceptively, the plant is very pretty and looks similar to other flowers in the garden,' say the experts at weedkiller brand Roundup. 'It has a green stem that is spotted with dark red and produces white flowers clustered in an umbrella shape.
'The sap within giant hodgweed contains toxic chemicals which can cause severe allergic reactions when it comes into contact with human skin.'
Where is it found?
Hogweed can be found along footpaths and riverbanks. Experts at the RHS say it is also most commonly found in gardens and allotments that are adjacent to infested woodland, heathland or common land.
Under schedule 9 of the Wildlife and Countryside Act 1981, you must not plant or cause giant hogweed to grow in the wild.
How dangerous is the plant?
If the sap of the plant comes into contact with your skin, it can cause severe, painful burns and make your skin sensitive to strong sunlight.
Research by A. Denness and A. Culham of the Centre for Plant Diversity and Systematics at the University of Reading, and J. D. Armitage of RHS Garden Wisley, shows that there are five species of giant hogweed and 'when tested all these had high levels of furanocoumarins (the chemicals which cause burning by making the skin sensitive to sunlight) and so all pose a risk to public health'.
Additionally, the RHS has highlighted native hogweed, Heracleum sphondylium, as more familiar to gardeners and those who like to go walking in the UK. It's a smaller plant than giant hogweed and can grow up to six foot when in flower, but it can still cause rashes and other skin complaints. Reactions tend not be as severe as with the larger species.
What should I do if I come into contact with giant hogweed?
The NHS advise: '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 should I do if giant hogweed is in my garden?
Specialists, Wise Knotweed, says the two most common ways to control giant hogweed is through the use of chemicals or excavation: 'Excavation is the quickest method to eradicate giant hogweed, although it is a more expensive option.'
For a garden, the experts at Roundup suggest: 'The plant is easily treated with Roundup Tough Concentrate. The ideal situation is to spray young giant hogweed foliage before it spreads. However if the weed is already rife in your garden it can be spot treated with a concentrated amount of Roundup Ultra and a pressure sprayer.
'Disposal of giant hogweed is vital to ensure it doesn't contaminate other areas of the garden. The best method is to burn all the waste rather than put it in your compost bin, as this could result in it being spread around your garden.'
Remember, when treating the weed it is important to cover arms and legs and wear a face mask to prevent skin coming into contact with the sap.
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Olivia Heath is the Daily Editor at House Beautiful. Heading up all things digital, Olivia loves nothing more than uncovering tomorrow's biggest design trends and revealing the best tips and tricks to help you decorate your home like an interior designer. Week by week Olivia shares the most stylish high street buys to help you get the look for less (while compiling her very own, and rather lengthy, homeware lust list) and showcases the best makeovers (who doesn't love a before & after?), as well as the hottest and most unique properties on the market.
Having covered interiors and gardens for the past seven years, Olivia’s work has also appeared on Elle Decor US, Country Living, Good Housekeeping, Red, Prima, Elle Japan, Modern Living and Micasa Revista.
Prior to joining House Beautiful, Olivia worked at Reveal magazine, where she reported on celebrity and entertainment news by day, and attended showbiz parties and red carpet events by night! Olivia has an MA in Journalism with an NCTJ qualification, as well as a BA in Journalism and Media & Cultural Studies.