Giant Hogweed (Heracleum mantegazzianum) FAQs

Frequently asked questions about Giant Hogweed  for a UK resident:

Commercial

Comprehensive invasive weed control

Residential

Find and tackle problem weeds

Knowledge Hub

Learn about conservation

Giant Hogweed (Heracleum mantegazzianum)

A towering and imposing plant that has become a growing concern across the UK.  This striking botanical beauty has now become a serious threat to both human health and local ecosystems.

An example of Giant Hogweed with Common Hogweed in the foreground
Example of a Giant Hogweed leaf.

Everything about Giant Hogweed is very big. Giant hogweed has huge leaves often over 1.5 m long sometimes more than 2m and flower heads up to 80cm or more wide. Stems are green with purple blotches and coarse white hairs.

Along riverbanks, ditches, waste grounds and gardens, but also can be found along field margins and woodland clearings. It thrives on damp, nutrient-rich soils.

It blooms from June to July, with white flowers clustered in an umbrella-shaped head.

By seeds, which can spread by water or ground disturbance.

Giant Hogweed is a herbaceous biennial, which means it takes two years to reach maturity to flower and seed. Once Giant Hogweed reaches maturity it grows rapidly, reaching heights of 3-5 metres.

Yes, giant hogweed is toxic. Its clear sap causes photosensitivity in the skin which can produce severe burns.

It can cause severe skin and eye burns, blisters, long-lasting scars.

Yes, avoid going near it and do not touch the plant. Cover exposed skin and wear gloves if removing.

By breaking the lifecycle and preventing seed production. Repeated treatments maybe needed. Seek expert help for large infestations.

Yes, it is illegal to plant or cause giant hogweed to grow in the wild under the Invasive Alien Species (Enforcement and Permitting) Order (2019).

Uncover the Secrets of Invasive Weeds

Subscribe to our YouTube channel for expert insights and practical tips on identifying and managing these relentless plant invaders

More from the Knowledge Hub

Gunnera tinctoria (Giant Rhubarb)
Giant Hogweed

Has Giant Rhubarb Just Been Banned in the UK?

The bottom line is – yes. Gunnera tinctoria (Giant Rhubarb), along with Giant Hogweed and Himalayan balsam plants have been transferred from the Wildlife and ...
Read More →
Giant Hogweed
Control

Where Does Giant Hogweed Grow? A Comprehensive Guide in the UK

The guide to where Giant Hogweed grows in the United Kingdom   Welcome, fellow homeowners and garden enthusiasts! If you’ve stumbled upon this blog post, ...
Read More →
Field horsetail Top four invasive weeds to be aware of in the Commercial Development Sector other than Japanese Knotweed.
Commercial Sector

Top 4 Invasive Weeds, other than Japanese Knotweed, to be Aware of in the Commercial Development Sector

Below is a detailed list of the top four invasive weeds to be aware of in the Commercial Development Sector other than Japanese Knotweed. We ...
Read More →
Giant Hogweed giant flower head
Giant Hogweed

Is Giant Hogweed Poisonous to Humans?

Is Giant Hogweed ( Heracleum mantegazzianum) poisonous to humans?   In a word, yes. This particular invasive weed species to the UK (originally native to ...
Read More →

Free Consultation

Book an appointment for a call back.

Factoids
Japanese Knotweed
Giant Hogweed
Bamboo
Hemlock
Himalayan Balsam
Hemlock Water Dropwort