From Knotweed to Hogweed...

Though Japanese knotweed is usually the plant that comes to mind when we think of hugely-invasive weeds, it is important not to forget that it has many contenders to that throne! One of these is the frankly frightening Giant hogweed which, looking like something from a Stephen King novel, is actually a real danger and could leave with with serious burns if you come into contact with it. Here’s how to spot it and what to do about it..

Recognising Giant Hogweed

The official name for the dangerous weed is Heracleum mantegazzianum, which is possibly a representation of the sound made by the first person to ever touch it. It has long, kush green stems that, as they reach their ends, branch out clawlike into revolting individual clusters of large… pretty, delicate, white flowers! Don’t be fooled by the pretty display, which mimics innocuous plants like cow parsley and elderflower - a closer look will reveal the characteristic thin spines, purple-spotted stems and stalks. As suggested by the name, this weed is BIG and can reach heights of almost 4m - flower-heads have been recorded with a width of half a metre.

Where Does it Originate?

Central Asia, from where a sample was brought in 1893. It readily took to the climate and soil of the UK and, a hardy plant, is a common sight nowadays along canal towpaths and on riverbanks.

What is the Danger?

It’s all in the sap – this sticky substance causes photodermatitis in humans, meaning that the skin becomes overly sensitive to UV light and essentially gets sunburn from even the mildest sunlight. Getting this nasty stuff in the eyes can lead to permanent blindness and just brushing against the plant can cause it to release.