Giant Hogweed

When venturing into the picturesque landscapes of the United Kingdom for a hike, it’s essential to appreciate and protect the natural beauty that surrounds us.

While many wildflowers enchant us with their vibrant colours and delicate petals, it’s crucial to be aware that not all flora is harmless. In this guide, we’ll highlight some flowers you should avoid during your hiking adventures to ensure your safety and the preservation of the UK’s diverse ecosystems.

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Giant Hogweed (Heracleum mantegazzianum)

Giant Hogweed, with its towering height and large white flower heads, may seem impressive, but it harbours a dangerous secret.

Its sap contains toxic chemicals that can cause severe skin burns and blisters when exposed to sunlight. Avoid contact with this invasive plant and keep a safe distance if you come across it.

Common Nettle (Urtica dioica)

While the Common Nettle may be a familiar sight, its stinging hairs can deliver an uncomfortable sting. These hairs inject histamine and other irritants into the skin, causing temporary pain and itching.

Wearing protective clothing or gloves can help prevent contact with this plant, ensuring a more pleasant hiking experience.

Hemlock Water Dropwort (Oenanthe crocata)

Hemlock Water Dropwort, with its delicate clusters of white flowers, may lure hikers with its beauty. However, this plant is highly toxic and can be mistaken for edible herbs. Ingesting any part of Hemlock Water Dropwort can lead to severe poisoning and even be fatal.

It’s crucial to learn to identify this plant and avoid consuming any wild vegetation during your hike.

Foxglove (Digitalis purpurea)

With its tall spikes of bell-shaped flowers in hues of pink and purple, Foxglove can be a tempting sight along hiking trails. However, all parts of this plant contain toxins that can cause cardiac issues if ingested.

It’s best to appreciate Foxgloves from a distance and refrain from touching or consuming them.


As you embark on your hiking adventures in the UK, it’s important to remember that some flowers may pose risks to your well-being. By familiarizing yourself with the flowers to avoid, such as Giant Hogweed, Common Nettle, Hemlock Water Dropwort, and Foxglove, you can ensure a safer experience on the trails while respecting the delicate balance of nature.

Enjoy the beauty of the UK’s flora from a distance, preserving their splendour for generations to come.

Tips on Staying Safe from Dangerous Plants Whilst Hiking

Educate Yourself: Familiarize yourself with the dangerous plants found in the UK, such as Giant Hogweed, Hemlock Water Dropwort, and Monkshood. Learn to identify them by their characteristics and understand their potential risks.

Research Hiking Trails: Before embarking on a hike, research the specific trails you plan to explore. Look for information about any known presence of dangerous plants along the route.

Stay on Designated Paths: Stick to established trails and paths while hiking. Straying into overgrown areas or off-path can increase the likelihood of coming into contact with hazardous plants.

Wear Protective Clothing: Protect your skin by wearing long-sleeved shirts, long pants, and closed-toe shoes while hiking. Consider lightweight, breathable fabrics that still provide coverage.

Use Gloves: Consider wearing gloves, especially when hiking in areas known for stinging plants like Common Nettle. This will help prevent direct contact and minimize the risk of skin irritation.

Maintain Distance: Keep a safe distance from plants that are known to be hazardous. Avoid touching or brushing against them, as some plants may release harmful substances upon contact.

Avoid Touching or Ingesting Unknown Plants: Unless you are certain of a plant’s safety, it’s best to refrain from touching or ingesting any wild vegetation. Resist the temptation to consume or handle unfamiliar plants during your hike.

Travel with a Guidebook or App: Carry a reliable guidebook or use a plant identification app to assist you in identifying plant species. These resources can help you differentiate between safe and potentially dangerous plants.

Travel in Groups: Hiking in groups enhances safety. If one person inadvertently encounters a dangerous plant, others can provide assistance or raise awareness about the potential risks.

Report Sightings: If you come across a dangerous plant while hiking, report it to the appropriate authorities or park rangers. Providing information about the plant’s location can help protect others and contribute to the preservation of natural environments.


What plants cause blisters in the UK?

One plant that can cause blisters in the UK is the Giant Hogweed (Heracleum mantegazzianum). Its sap contains toxic chemicals that, when exposed to sunlight, can cause severe skin burns and blisters.

What plants sting in the UK?

The Common Nettle (Urtica dioica) is a plant that stings in the UK. Its stinging hairs inject histamine and other irritants into the skin, resulting in temporary pain and itching upon contact.

Is it OK to touch foxglove?

It is generally advisable to avoid touching Foxglove (Digitalis purpurea) with bare hands. All parts of the plant contain toxins that can cause cardiac issues if ingested. It’s best to appreciate Foxgloves from a distance and refrain from touching or consuming them.

What is the poisonous purple flower in the UK?

The Monkshood or Wolfsbane (Aconitum napellus) is a poisonous purple flower found in the UK. It contains potent toxins that can be harmful if ingested or even if there is skin contact with its sap.

What poisonous plant has blisters in the UK?

The Giant Hogweed (Heracleum mantegazzianum) is a poisonous plant in the UK that can cause blisters. Its sap, when exposed to sunlight, can lead to severe skin burns and blisters upon contact.

What plant causes instant blisters?

The plant that is notorious for causing instant blisters upon contact is the Giant Hogweed (Heracleum mantegazzianum). Its sap contains phototoxic chemicals that react with sunlight, leading to immediate skin irritation, burns, and blisters.

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