Hogweed is a common plant found across much of the world, from North America to Europe and even Asia. It is typically an invasive species that can quickly overrun gardens and fields. But what makes hogweed particularly dangerous is its sap – it contains chemicals which can cause severe skin irritation or even worse if you touch it without protection. In this article, we will explore the toxicity of hogweed, as well as what you should do if you come into contact with it and how to protect yourself and your pets.

Common Hogweed Flowerhead
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Is Common Hogweed Poisonous to Touch?

Yes, common hogweed (Heracleum sphondylium) is poisonous to touch although only mildly. The sap of the plant contains a chemical called furocoumarin, which can cause redness and irritation when it comes into contact with the skin, especially when exposed to sunlight. Common hogweed is not as toxic as its relative, giant hogweed (Heracleum mantegazzianum), which can cause severe burns and blisters on the skin. It’s essential to differentiate between the two species and exercise caution when handling either plant.

Note: Although common hogweed isn’t as toxic as giant hogweed, it can still cause serious skin reactions in people with sensitive skin.

What are the Symptoms of Common Hogweed Poisoning?

The reactions to common hogweed can differ based on the mode of exposure and individual sensitivities. Generally, the signs manifest as:

Signs After Direct Skin Contact with Common Hogweed

  • Immediate Reactions: Within 48 hours of contact, the skin may show redness and itchiness.
  • Blistering: Blisters can develop, which may be painful.
  • Photosensitivity: The exposed skin might become highly sensitive to sunlight, lasting for several months.
  • Long-Term Effects: In more severe instances, the blisters can evolve into purplish or blackened areas, leading to skin peeling.

If any blistering occurs, seek medical attention immediately!

Signs After Consuming Common Hogweed

  • Digestive Distress: This includes symptoms like nausea, vomiting, abdominal pain, and diarrhoea.
  • Severe Reactions: In extreme cases, ingestion can lead to complications like kidney malfunction, convulsions, or in rare instances, fatality.
Common Hogweed Growing on the Edge of a Cowfield
Common Hogweed Growing on the Edge of a Cowfield

What To Do If Someone Eats Common Hogweed?

If someone ingests common hogweed, take the following steps:

  1. Seek Immediate Medical Attention: Call emergency services or your local poison control centre right away. They can offer specific advice based on the situation.
  2. Do Not Induce Vomiting: Unless instructed by a medical professional, do not try to make the person vomit.
  3. Stay Calm and Monitor: Keep the person calm and monitor their condition. Note any symptoms or changes in their behaviour.
  4. Provide Information: If possible, determine the amount of hogweed consumed and the time of ingestion. This can help medical professionals assess the situation and provide appropriate care.
  5. Stay with the Person: Do not leave the affected individual alone. Stay with them until medical help arrives or they are in a safe location.

What To Do If I Touch Common Hogweed?

If you touch common hogweed (Heracleum sphondylium), follow these steps:

  • Wash the Area Immediately: Use cold water and soap to thoroughly wash the affected area to remove any sap residue.
  • Avoid Sunlight: The compounds in hogweed sap can make the skin more sensitive to sunlight, potentially leading to photodermatitis. Keep the affected area out of direct sunlight for a few days.
  • Apply a Cold Compress: If you experience skin irritation, applying a cold compress can help reduce inflammation and soothe the skin.
  • Monitor for Symptoms: While common hogweed is less potent than giant hogweed, some individuals may still experience skin irritation. Look out for redness, itching, or blisters.
  • Seek Medical Advice: If you develop severe skin reactions or are concerned about your symptoms, consult a healthcare professional for guidance.
  • Wear Protective Clothing: If you need to handle or remove hogweed in the future, wear gloves, long sleeves, and eye protection to prevent skin contact.
Common Hogweed aka Cow Parsnip
Common Hogweed aka Cow Parsnip

Is it Safe to Grow Common Hogweed at Home?

Growing common hogweed (Heracleum sphondylium) at home is not recommended due to its potential risks. While it might be less toxic than its giant cousin, it can still cause skin reactions, especially when exposed to sunlight. These reactions can range from mild irritation to severe burns and blisters. Additionally, if ingested, the plant can be toxic. If you have children, or pets, or frequently have visitors in your garden, it’s best to avoid cultivating common hogweed to prevent accidental exposure or ingestion.

Note: It is safe to grow common hogweed at home if you are a competent adult who is aware of the risks and takes appropriate precautions.

Is Common Hogweed Poisonous to Pets?

Yes, common hogweed can be harmful to pets. If your pet comes into contact with the sap, they may experience similar symptoms to humans, such as skin irritation, redness, itching, and blistering. Ingesting the plant can also cause gastrointestinal distress, such as vomiting, diarrhoea and even kidney failure. It’s best to keep your pets away from common hogweed and any other potentially dangerous plants.

Note: If you suspect your pet has come into contact with or ingested common hogweed, it’s essential to consult with a veterinarian promptly to ensure their safety and well-being.


Common hogweed is a highly toxic plant that can cause severe burns and blisters when it comes into contact with the skin. It can also cause other health problems if ingested. It’s important to take precautions when working around the plant, such as wearing protective clothing and washing the skin immediately if contact is made. While it may be safe for a competent adult to grow common hogweed at home, it is important to take the necessary precautions and be aware of the potential risks to young children, pets and the environment. If you are not comfortable taking these precautions, it is best to avoid growing common hogweed at home or getting rid of it if it is already growing.

What to Do if Someone Eats Common Hogweed Infographic
What to Do if Someone Eats Common Hogweed Infographic

Garden Doctor Tips

“Common hogweed’s toxicity is enhanced by the sun, so it is important to avoid handling the plant in direct sunlight to minimize the risk of burns and blisters!”

“If you come into contact with the sap of common hogweed, it is important to wash the affected area immediately with soap and water!”

“If you experience symptoms such as redness, itching, or blistering after coming into contact with common hogweed, it is important to seek medical attention immediately!”

“If you suspect that common hogweed is present on your property and you are not comfortable handling it yourself, it is best to contact a professional for proper removal and disposal!”

Frequently Asked Questions

What part of Common Hogweed is poisonous to dogs?

All parts of Common Hogweed are poisonous to dogs.

Can you die from Common Hogweed?

While it is rare, it is possible to die from Common Hogweed, particularly if a large amount of the plant is consumed.

How much Common Hogweed is fatal?

The amount of Common Hogweed that is considered fatal can vary depending on the individual and their sensitivity to the plant. It is important to seek medical attention immediately if any symptoms occur after ingesting Common Hogweed.

Should I get rid of Common Hogweed?

Yes, it is recommended to get rid of Common Hogweed as it can pose a risk to human health, pets and the environment.

What are the immediate symptoms of common hogweed poisoning?

Symptoms are not always immediate, and they can start up to 48 hours after you have touched the plant.

How long does it take for symptoms to appear after contact with common hogweed?

Symptoms of common hogweed poisoning typically appear within 48 hours of contact with the plant.

Can common hogweed poisoning lead to long-term health problems?

Yes, common hogweed poisoning can lead to long-term health problems such as scarring and permanent sensitivity to sunlight in the affected area. In severe cases, it can also lead to blindness if the sap enters the eyes.

Is it safe to handle common hogweed after it has been cut or dead?

No, it is not safe to handle common hogweed even after it has been cut or dead as the sap of the plant is still toxic. It is important to take precautions such as wearing protective clothing and gloves when handling the plant.

What Toxins Does Common Hogweed Contain?

One of the most notable characteristics of common hogweed is that it is highly toxic to the skin. The sap of the plant contains a chemical called furocoumarin.


Trevor Wright is not just a seasoned horticulturist; he’s the esteemed Garden Doctor. With a BSc in Horticulture and years of hands-on experience in the soil, Trevor has become a trusted mentor for all things gardening. As the founder of Garden Doctor, he’s committed to clarifying the intricacies of gardening, offering straightforward advice that’s rooted in years of practice. His writing is a garden of how-tos, savvy insights, and comprehensive guides that enable individuals to nurture and grow their garden dreams. When he’s not knee-deep in garden beds, Trevor is at his keyboard passing on his green-thumbed wisdom to budding gardeners, ensuring that the legacy of sustainable and joyful gardening blossoms far and wide.

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