For a ground-level assessment of giant hogweed anywhere in the UK, contact Arbtech and request a quote for a giant hogweed survey.
Last updated: March 2026
Editor at Arbtech, Rob is a content specialist who manages our ecology and arboriculture services copy to ensure it is accurate, up to date, and insightful for current and future clients.
Giant hogweed can be a serious health hazard and a major roadblock for your planning application. If you’ve spotted this invasive species on your site, you need to act fast to avoid costly delays and legal headaches.
At Arbtech, we provide expert giant hogweed surveys starting from £599.
Our local specialists will conduct a thorough ground-level assessment to identify the extent of the infestation and provide the practical solutions you need to keep your project moving.
Under the Wildlife and Countryside Act 1981, it is an offence to cause giant hogweed to grow in the wild. You are responsible for preventing its spread.
The sap contains toxic chemicals that cause severe skin burns and blistering when exposed to sunlight.
Undetected invasive species can trigger significant delays. We help you navigate the requirements of your local planning authority.
We carry out surveys between May and September when the plant is most visible. Once the assessment is complete, we’ll provide a clear report and recommend the best control methods – such as herbicide application or root removal – to clear your site.
Don’t let invasive plants derail your development. We cover the whole of the UK and offer a rapid, reliable service to help you get planning permission.
Get your free, no-obligation quote today and let’s get your project started.
Evidence that suggests or confirms that giant hogweed is on your development site should be taken seriously, as it has the potential to cause a variety of hindrances to your plans. Going undetected means enabling it to trigger any level of costly delays to your plans and throw your planning application into uncertainty.
Instead of chancing major issues with your planning project, it would be wise to consider arranging a giant hogweed survey and allowing our team to produce suitable solutions. On this page, you will be able to learn more about what giant hogweed is, how it can harm a development, and why an assessment will solve any problems relating to it.
Scientifically titled Heracleum mantegazzianum, giant hogweed is a large plant capable of spreading fast across large areas. Seeds blown from the plant can spread via the wind and watercourses, making it possible to travel short and long distances and grow in numerous spaces.
Each plant has the capability to produce anywhere between 20,000 and 100,000 seeds, and once dispersed, over 90% of them could germinate. Giant hogweed comes from the Apiaceae family formally known as Umbelliferae alongside common carrots, coriander, cumin, parsley and parsnips.
The earliest reference to giant hogweed dates back to 1817 when it was mentioned in the Royal Botanic Gardens Kew Seed List. At that time, it was solely named Heracleum giganteum and was one of several seeds supplied to Kew Gardens by the Russian Gorenki Botanic Gardens.
It was originally introduced to Britain and wider Europe from the Caucasus Mountains with the intention of using giant hogweed in ornamental gardens. By 1828, however, it had escaped into the wild and became known as an invasive non-native species, primarily populating the country’s riverbanks.
Based on a proven ability to cause hazards to human health and the environment, giant hogweed is regarded as an invasive species of plant. All plants within this category are listed in Schedule 9 of the Wildlife and Countryside Act 1981, meaning that any practices involving the planting or distribution of giant hogweed are against the law.
Whenever giant hogweed is present on a property, it is the responsibility of the property owner to prevent it from spreading to neighbouring areas. In addition to the Wildlife and Countryside Act 1981, giant hogweed also appears within other such legislation as the Anti-Social Behaviour, Crime and Policing Act 2014, the Control of Pesticides Regulations 1986, and the Invasive Alien Species (Enforcement and Permitting) Order 2019.
Albeit a visually enticing plant, giant hogweed can in fact prompt multiple issues to the environment and people within the nearby vicinity. In terms of the impact on nature and general ecology, giant hogweed’s status as an invasive species poses a threat to biodiversity and the continued health of local ecosystems.
Sharing similarities with Himalayan balsam, it can grow across the sides of riverbanks and other locations close to water. Due to the dense clusters it creates, once it dies back in the winter months, the gap left behind can result in an erosion of the surrounding infrastructure. Himalayan balsam also dominates vast areas, altering the behaviours, movement and available nutrients for other plant habitats.
Within the sap of the plant is a chemical known as furanocoumarins. It is toxic to humans and has the ability to trigger harmful reactions in a number of ways. Most notably, if sap touches human skin and then comes into contact with the sun, the ultraviolet rays can cause a severe skin reaction called phytophotodermatitis. Other impacts on skin also include blisters, burns and long-term scarring.
Other side effects experienced by humans due to the poisonous nature of giant hogweed include a risk of blindness and a feeling of long-term sensitivity in the skin after exposure to it. It has also been reported that the symptoms may be delayed, taking between 24 and 48 hours to show. As such, anyone in contact with giant hogweed is advised to avoid the sun, seek medical attention straight away, and avoid handling but handle with extreme caution if it is strictly necessary.
Whether it emerges on a development site or private property, identifying giant hogweed is crucial, as finding it early will prevent it from becoming more widespread, disturbing larger areas and faltering the continued activity of a higher number of animal and plant habitats.
As with other invasive species such as Himalayan balsam and Japanese knotweed, giant hogweed shares certain similarities in the impact it has but not its appearance. Avoid any misunderstanding with spotting giant hogweed by referring back to the description provided below.
Sometimes compared in appearance to common cow parsley or Queen Anne’s lace, giant hogweed has clear distinctions that make it stand out compared to other invasive plant species. For instance, each flower head is formed of large clusters of white flowers known as umbels.
The flower itself is as large as 14 feet tall, surpassing the size of Himalayan balsam and Japanese knotweed. It also has a thick and long stem covered in bristly hairs and purple patches, and the leaves are as wide as up to five feet in width, surrounded by a serrated edge.
Following a lengthy period of spreading across England, Scotland, Wales and Northern Ireland, giant hogweed has been known to occupy various sections of the UK.
Common areas where the plant is typically spotted include:
If you have reason to believe that giant hogweed may be in circulation somewhere on your development site, you may be wondering if you are legally or even just morally obligated to report it. Both local authorities and relevant environmental agencies will accept reports on it and other invasive species, so it’s vital to harness a working knowledge of when to submit a report or if to report it at all.
Under UK law, you are not required to report any sightings of giant hogweed. As previously mentioned, however, it would be against the law for someone to actively plant it or undertake any other actions that could result in it growing or spreading in the wild. Instead, any control methods undertaken by professionals would be encouraged to evade unnecessary harm to the natural environment.
Since there are no legal requirements in place to insist on anyone reporting giant hogweed, it isn’t something that landowners or property owners need to be worried about. That said, it could still be worth reporting in a selection of situations, such as:
To sufficiently address the significant threat brought to your development and the environment as a whole by giant hogweed, an inspection will be needed, managed by a qualified ecological consultant. At this point, a ground-level assessment of the entire site and all of the main tributaries will be undertaken, enabling the ecological surveyor to retrieve further information and perform suitable control work.
In the section below, we’ve explained how Arbtech would typically organise a giant hogweed survey for you, including key aspects such as the ideal timing, predicted cost and possible methods of getting in touch to get the ball rolling and request a quote.
Using a comprehensive knowledge of listed animal and plant species, our team are equipped to attend development sites and assist with surveys of all present ecological features. From giant hogweed to injurious weeds and Himalayan balsam to Japanese knotweed, we can help with any invasive species, not limited by your precise location.
Every time you book an assessment with Arbtech, you are assured of being given a local expert with impactful insight into the area, present ecological assets and the relevant local planning authorities. You will also find that every member of our team is directly employed by the company and ensures the same level of quality in the work they do.
All plants undergo various changes throughout the year. Between May and June, each flower head of giant hogweed becomes clearly visible. It then goes on to reach the maximum height between July and August, lasting all the way until September. At this point, it begins to die back as the months grow colder, eventually growing again the following May.
Survey season for the giant hogweed plant typically takes place between late spring and early autumn, giving us an opportunity to conduct giant hogweed surveys between the months of May and September. Operating within this time frame guarantees optimum identification and control prior to the plant releasing seeds and making matters worse.
An assortment of different factors can affect the overall cost of a giant hogweed survey, including the purpose of the assessment and the specifications of the development site. Arbtech places a particular emphasis on getting the details right, as it keeps costs low where possible and prevents any likelihood of unfairly overcharging a client.
We follow the same structure in pricing up all of our surveys, starting with a standard cost before building on it based on the scale of the project and the size of the site. The quoted price will account for the entirety of the assessment from desk study to field study and report, and with ecologists situated across the country, all travel expenses are subsidised.
On a date decided to fit in with your schedule, one of our team can attend your site and carry out a giant hogweed survey. The further information we gather can then be used to gauge any overlap between your plans and the presence of the plant, delivering suitable control work such as a return to the site to cut tap roots or apply herbicide.
Bypass troublesome obstacles with obtaining planning permission by getting in touch and providing us with details of your site and project. In return, you will receive a free quote for you to look over and the freedom to choose a date for a giant hogweed survey. You can do this by messaging us on our socials, emailing us, calling us, or visiting our website and filling out a quote form.
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