General precautions
If you choose not to treat or eradicate invasive weeds, they will spread over time and can cause damage to structures such as building foundations.
Good practice
Keep areas that contain these species fenced where possible. The fence should be at least 3m away from the plants.
Put up ‘keep out’ signs around fenced areas.
Put up posters in offices and communal areas to explain to employees what the problems are and what they need to do. Include pictures of the invasive weeds you have on your premises or site. This is particularly important for giant hogweed as contact with sap from the plant can make skin hypersensitive to sunlight, causing skin burns.
Additional precautions for Japanese knotweed
What you must do
Fence any area of Japanese knotweed with clear signs so that only appropriately briefed personnel enter the enclosure to deal with the infestation or resulting waste. This includes areas with waste plant material or soil contaminated with Japanese knotweed.
Do not use tracked vehicles within the affected area, and make sure any vehicles leaving the area are pressure washed.
Never strim areas containing Japanese knotweed. If you are going to clear areas where Japanese knotweed is present, make sure you remove all cut stems. You should use a collection bucket.
Cut plant material from Japanese knotweed will not compost - it will produce new plants. Do not attempt to compost cut plant material or waste from strimming.
Do not put cut plant material directly onto the ground. If you must stockpile cut material, make sure it does not come into contact with soil, for example place it on top of a barrier membrane.
Do not mix clean soil with contaminated soil. This contaminant grows, you will end up with twice as much contaminated soil as you started with.
Additional precautions for giant hogweed
Giant hogweed has toxic sap. When the sap comes into contact with skin, it reacts with sunlight and causes chemical skin burns.
The stem and underside of the leaves have hairs very much like a stinging nettle. Brushing against giant hogweed can be enough to get sap on your skin.
What you must do
If you have giant hogweed on your land, it is your duty to ensure that the public and your employees are protected from the hazards associated with it.
Do not use a strimmer on giant hogweed. The sap from the plant may get onto your skin or into your eyes.
Good practice
Do not cut down or handle giant hogweed once it is fully grown. If you intend cutting this species back, do it before the plant reaches 1.5m in height.
If you are going to get close to or handle giant hogweed, wear full wet-weather clothing with gloves, a hood and a full-face visor. Wash down your waterproof clothing before you take it off.
If you get sap on your skin, cover it to keep it out of the sun. Go indoors immediately and wash the sap off your skin with soap and lots of water.
Giant hogweed sap can become more toxic as the year progresses and the plant is exposed to more sunlight.
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