I'm doing a lot of strimming and will often chop through a stand of Balsam to discover that I just sliced through a hogweed as well. The sap from these chopped plants is constantly spraying me in the face and on bare arms (in T-shirt weather). Am I at risk?
YES Geoff you are! And Chubberbob is correct in what he says.
My advice to anyone strimming on the river is full Personal Protective Equipment including a plastic visored face mask and gloves. Not the meshed one that come as a package with the strimmer.
Risk assess the area to be strimmed first, by a walkover to make sure there is no Gt. Hogweed present. If present, leave a 3 M circle around it not strimmed. Yes the plant can have that much spread. Complete the strimming first then deal with the hogweed last still in full PPE.
Two ways of cutting hogweed, either using a very sharp sickle that will cut through it with one blow or a fold up pruning saw that will saw threw the main stalk.
1) First take off all the lower leaves to a height of about 3 ft so you can see the main stalk and swing or get in to saw it unhindered.
2) Cut the plant about 4 - 6 inches above the ground with one blow (sickle) or several pulls with the pruning saw. Despite the large diameter of the main stalk it cuts quite easily, unless you try to cut it where there’s a knot segment. So avoid cutting it at the knot.
We tend to leave the plant where it’s been cut rather than move it. By moving it there is the risk that you inadvertently get the sap on you and the very real risk of burns.
A warning notice on the car park gate is helpful that there is freshly cut Hogweed on the banks and it must be avoided.
Within 3-5 days the plant poses no risk to anyone.
Optimum time to cut it is a week or so after the flower head has bust into flower and before the seed forms and start to ripen.
The plant by this time has put all its energy into flower formation and has none left to regrow a new central stem.
Hogweed btw is a spring and very early summer plant and under normal conditions would be setting seed by mid July. It was very late this year.
Can I stress again it should not be touched unless you know what you are doing and you are wearing full PPE.
One last point as Knotweed has been mentioned, do not strim, cut or dig this stuff, as it will only encourage the plant to spread. It is an offence under the Wildlife and Countryside Act to do any of the above. The plant once cut is classed as Special Waste (TOXIC) and can only be dealt with by a specialist waste contractor for removal to a Special Waste site. Where it must be buried 10 metres deep.
It can be treated on site by a specialist herbicide contractor that holds all the spraying licences needed to do this.
Do not attempt to do this yourself or as a club as the fines are very high indeed, when you are caught.