Invasive Species: Beware of the Giant Hogweed!

Posted on July 20, 2017
Archive : July 2017
Category : GO SAFE

As we reach the summer months, invasive plant species like Japanese knotweed and Himalayan balsam can be a big problem on site. They can spread quickly and cause severe damage to the environment, including out-competing other plants and eroding river banks.

“A few years back, we went to one site in the Midlands and at the end of March there was half an inch of knotweed showing,” says Chris Swainston, Geotechnics’ Principal Environmental Engineer. “We did the intrusive works and then came back to do the monitoring a month and a half afterwards. Around May-June, the knotweed was as high as my head over an area of about 100 square metres. It shoots up everywhere”.

“The problem with knotweed is that it doesn’t reproduce by flowers and seeds - it regenerates. A part larger than your thumbnail can potentially create a new plant. As a consequence, you really do not want to take any knotweed off site. That’s why it’s an offence to knowingly spread it anywhere else: it is very invasive, and it is very expensive and difficult to remove when it takes hold”.

As well as harming the environment, some species can cause long-lasting injury. “Giant hogweed is problematic because of the effects it can have if you brush up against it,” says Chris. “If you do that, you can be subject to photo sensitive dermatitis”. This can result in extremely painful blisters that can recur over several years.

That is why our latest GO SAFE campaign is raising awareness of invasive species on site. Look out for our new blogs and posters to find out how you can stay safe. We are also developing a pocket guide to invasive species to go out to Geotechnics staff to make them aware of the dangers.

GO SAFE Invasive Species Poster

Our new poster will be in our offices and on our sites very soon! Click on the image to download a PDF version.