Giant hogweed (Heracleum mantegazzianum) makes headlines for all the wrong reasons. The non-native invasive plant contains toxic sap that sensitises skin to sunlight and can cause severe blistering, which turns to scars that can last for several years. The plant is listed on Schedule 9 of the Wildlife and Countryside Act 1981, which states that it is a statutory offence “to cause or allow it to grow in the wild”.
RSK experts were called to a large housing development in Scotland, about 10 km east of Dundee, where they confirmed and mapped giant hogweed on and around the site. The outbreak was extensive, covering about 730 m3, particularly along the Dighty Water stream; isolated plants were also found close to paths and benches.
We provided immediate advice on managing exposure and developing a long-term plan to remove the risk and protect the public. RSK environmental scientist Jo Farndon outlined the five-year plan: “Our strategy was to cause minimal disruption by decapitating the flower heads to prevent further spread and herbicide treatment of germinated plants. Glyphosate was selected as the most appropriate herbicide owing to the proximity of the plants to the river. Approval to spray was received from the Scottish Environmental Protection Agency.”
RSK continues to consult with all stakeholders on the management strategy and ensures that residents have the information necessary to identify giant hogweed and understand its potential hazards.