Giant Hogweed

The Giant Hogweed

The Dangers:

Unlike Japanese Knotweed, Giant Hogweed will not damage property but is a threat to human health; extreme caution must be exercised when coming into contact with this plant.

The stem and leaf stalks contain a sap that is released by handling, cutting or just brushing against the plant. The sap contains psoralens that photosensitise the skin so that exposure to sunlight results in very painful blistering, sometimes requiring hospital treatment. Blindness can be caused with eye contact with the sap. The burning effects can last 3 years or more and tissue scarring for more than 15 years has been recorded.

Do not attempt to strim, slash, dig out, walk amongst, pick or remove Giant Hogweed without full protective clothing. Any infestation should be fenced off with clear warning signs posted if appropriate.

Each giant hogweed plant is capable of producing about 50,000 seeds and, though they only drop close to the plant, they can be transported on shoe soles to other areas. The seeds can remain viable for 12 years meaning that total eradication is a long and expensive process. A reasonable measure of control can be achieved quickly though by a combination of removal of seed heads and sustained herbicidal treatment.


At JKS our Giant Hogweed treatment methods are designed to initially kill existing Giant Hogweed and then eliminate the remaining seed bank. Effective Giant Hogweed control is dependent on an appropriate treatment strategy.

Giant Hogweed is invasive because a mature plant can produce 20-80,000 viable seeds each year. The potential for this plant to exploit your land is unlimited, so utilising our expertise to combat the plant is vital.

If you think you may have Giant Hogweed on your land book an appointment for a site visit and we can give you a quote for a treatment programme or send pictures to

Reasons for choosing Japanese Knotweed Specialists!

• NPTC qualified field technicians with PA1 & PA6AW certificates for applying herbicide & weed killer

• Fully insured including Professional Indemnity insurance

• All invasive weeds solution packages are completed in accordance with Environment Agency & SEPA recommendations

To discuss Giant Hogweed, call us on

0800 038 7108 or 07900 082 338