What is Giant Hogweed?
Giant Hogweed is an invasive plant originating from Central Asia where is occurs in damp upland areas. The plant relies solely on seeds for reproduction and spread. It only takes a single plant germinating from as little as one seed to cause an invasion. This is especially worrying as each flower of a single umbel produces 30 to 50,000 seeds.
Giant Hogweed identification
Giant Hogweed can reach heights of 5 metres high with small, creamy-white flowers. The numerous flower umbels on each stalk can each measure up to 2 feet. It can easily be identified by its large size, spiked leaves and large flowering head.
Is Giant Hogweed poisonous?
Giant Hogweed is dangerous because its sap is harmful to humans through its ability to cause skin inflammations. The species is phototoxic, which means that if the skin comes into contact with the plant and then direct sunlight, it can cause a red rash, often followed by severe burns and blistering within 24 hours.
The resulting burns can last for several months and, even once they’ve gone, skin can remain sensitive to sunlight for years to come.
The highest levels of sap have been discovered during the month of June, so this part of summer is a time to be particularly aware when handling or coming into content with Giant Hogweed. It’s important to know how to identify Giant Hogweed to protect yourselves and other people who could potentially be coming into contact with Giant Hogweed on your property.
Giant Hogweed legislation
There are numerous laws put in place to prevent the spread of this invasive plant. If you find Giant Hogweed, it is crucial you read these laws before attempting removal as you could be breaking the law.
As an invasive species listed under Schedule 9, if Giant Hogweed is found on your land, you as the owner are responsible for preventing it from spreading beyond your land. Failure to do so could result in criminal action.
Fortunately you do not legally have to remove Giant Hogweed from your property or land as long as you are actively taking steps to ensure it does not spread to neighbouring land. However its toxicity from its sap may be a factor to your decision to remove the plant, especially if present in an area that is frequently used.
Giant Hogweed is also covered under laws when dealing with the plant and disposing it from your property. Read more about legislation surrounding Giant Hogweed.
Giant Hogweed removal
It is recommended to apply herbicide early in the growth of this species, before the plant flowers and seeds.
Chemical control needs to be consistent over a number of years to have any considerable effect. There is legislation around spraying chemicals in the wild, so it is best to do your research and hire professionals that can remove in line with legislation and best practice.
To mitigate the risk of contamination and destruction of nearby plants, manual control and removal of Giant Hogweed is often favourable. Cutting the plant out from the roots is highly effective, but must be undertaken with extreme care by experienced professionals.
Cutting the plants themselves will often only encourage faster regrowth and more flowering shoots, and in some cases can help spread the plant’s seeds even further. Strimming and trimming for cosmetic effect is not recommended.