An invasive species expert has warned that Scotland is facing a huge year for the proliferation of highly caustic Giant Hogweed after identifying the emergence of the plant much earlier in the year than might be expected.
Keith Gallacher, director of Complete Weed Control, one of Scotland’s leading weed control, ground maintenance and tree management specialists, spotted young shoots of the rapidly-spreading and dangerous plant emerging from winter dormancy in March.
He warned that this is unusually early for the enormous Heracleum Mantegazzianum, which can grow up to six metres high and whose sap can cause severe burns with lasting effects such as scarring and chronic dermatitis.
He said that the early showing of Giant Hogweed could have been precipitated by mild and wet spring weather – March had 27% more rainfall than normal in the UK – and that it could lead to greater infestations of the plant, which can spread tens of thousands of seeds after it flowers in June and July.
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.”
Complete Weed Control, which now covers the greater part of Scotland from its recently-acquired base in Larkhall, will treat the plants but has warned 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.”
Complete Weed Control has continued to gain prestigious contracts from clients across Scotland and has posted a record £2.75 million in sales last year, up from £2 million the previous year.
Growth has been boosted by new client acquisition as well as its tree services division, which now contributes equally with the longer-established weed suppressant and grass cutting services it supplies to mostly public sector organisations.