Giant hogweed… the killer weed

Wednesday 12th July 2017

As regular readers will know, I try and avoid using scary language in these blogs. There are plenty of other websites out there that try to scare you. So why the scary heading? Well Giant hogweed is a scary weed.

Giant hogweed originates from the Western Caucasus in Southwest Russia. It is a short lived perennial typically taking 3-5 years to grow from a seed, flowering in its last year and then dying. Each plant typically produces 20,000 seeds in its final year – although it can produce much higher numbers of seeds in favourable circumstances.

Doesn’t sound scary? Well consider this: the sap from this plant is a known biohazard. If the sap (especially from a flowering plant) gets onto your skin, the sap removes your natural skin protection from normal sunlight and your skin burns and blisters when exposed to sunlight. If you get sap into your eyes you can be temporarily or permanently blinded. If you get sap around your mouth you can choke and die. Fortunately the worst cases of human health issues are rarely seen in this country, however the blistering and burning are quite common and symptoms may persist for years.

Still not scary enough? Giant hogweed sap is a known mutagen and may cause mutations in foetuses so should be of particular concern to pregnant women and other mammals.

We frequently treat Giant hogweed and use special extending lances to apply herbicide (and so avoid contact with the plant). We have been appalled by seeing some people recently who on finding out that they have Giant hogweed then decide to chop it down! This is not a good idea… even if you take a lot of precautions you are still exposing yourself to a lot of biohazardous sap and this should only be done by specialists in extreme circumstances; for instance in areas where you cannot fence the area off and/or use signage to exclude people from the area while treatment is taking place.

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