Giant Hogweed: UK’s ‘most dangerous’ plant set to have bumper year thanks to mild and wet weather

Britain is facing a record invasion of Giant Hogweed - as mild and wet weather sees it boom earlier than ever, experts say. Warnings have been issued over the invasive and dangerous toxic species - dubbed UK’s ‘most dangerous’ plant.

Its sap can cause highly painful burns, which blister within 48 hours, often hospitalising people and leaving them with permanent scars. Landowners and gardeners who fail to clear it from their land have in the past been handed anti-social behaviour orders.

Now Britain is facing a ''huge year for the proliferation'' of Giant Hogweed after identifying the emergence of the plant much earlier in the year than expected. The plant, known in Latin as Heracleum Mantegazzianum, can grow up to six metres tall.

Keith Gallacher, director of Complete Weed Control in Scotland, who handles ground maintenance and tree management, spotted young shoots of the rapidly-spreading and dangerous plant emerging from winter dormancy in March.

Mr Gallacher said: “Our teams saw the much-earlier-than-expected appearance of the young Giant Hogweed during routine inspections in East Lothian, near Musselburgh. With such an early start, and with the rate of growth of which the plants are capable, it is likely that 2024 will be a bumper year for this rapacious invader.

“Like many invasive species, such as Japanese Knotweed and Himalayan Balsam, it was brought to the UK as an architectural oddity, but now it has escaped and, without any natural enemies, it grows into dense colonies, especially along watercourses.

“It is part of the Apiaceae family, which includes carrots, parsnip, cumin, coriander and parsley, but its dense foliage prevents light reaching the soil underneath, killing off native plants and leading to rapid soil erosion.”

Keith believes that the early showing of Giant Hogweed could have been caused by spring showers - with March seeing rainfall levels up by 27%. With the plant able to spread tens of thousands of seeds after flowering in mid-summer, Keith says that eliminating Giant Hogweed requires a concerted and sustained effort by all landowners in an affected area.

He said: “If you leave it too late, the plants get larger and become more difficult to spray, and require more herbicide. But if you do it too early and you get the torrential rains like we’ve had these last few weeks, the herbicide won’t have much effect.”