Giant Hogweed(Heracleum mantegazzianum) is a non-native plant species that grows abundantly along rural roadsides and the banks of rivers. It has a negative ecological impact on infested river catchment areas. It can reach up to 5 metres in height. Stems widths are up to 10 cm in diameter. The stem itself is green with purple hue and has raised collar areas. Each purple area on the stem is surrounded by tough bristles or hairs and there are coarse white hairs at the base of each leaf stalk. The plant has compound leaves which are deeply toothed and grow up to 1 m in width. Giant Hogweed is a human health hazard as it produces a sap that causes painful blisters on human skin as shown. The sap can permanently affect the skin’s ability to resist ultraviolet light. Great care should be taken, and protective clothing worn, when cutting vegetation during roadside or riverbank maintenance programmes. Spot treatment with a suitable chemical product will halt the development of plants but bear in mind that very few products are cleared for use near watercourses.
Giant Hogweed is listed as an invasive weed in the Control of Aquatic Invasive Species and the Restoration of Natural Communities in Ireland (CAISIE) – European Commission Life+ Programme.
If you have a problem with invasive weeds in your local authority area, on club grounds or a private property that you manage, call us for professional assistance and service.