Hogweed and giant hogweed 7   Recently updated !

Note : Please don’t send me photos or ask me to identify trees, plants, berries or mushrooms.

I’ve written posts in the past to help tell apart edible plants from poisonous ones, such as this one on hemlock and cow parsley and this one about foxgloves.

This time I want to look at common hogweed and giant hogweed.

Nicola and I eat a lot of common hogweed (Heracleum sphondylium) at this time of year, the smell of it cooking is just wonderful. I like it with eggs, in an omelette or a quiche topped with a little blue cheese.  We also have it griddled, a bit like asparagus, with olives and some chilli flakes, which is delicious.

But you need to make sure that what you’re picking is common hogweed and not giant hogweed.  Giant hogweed (Heracleum mantegazzianum) isn’t a native plant, it was introduced into the British Isles in the 1800s and has rapidly spread.  It tends to be found on river banks and alongside canals (but not always); the photo below was taken alongside the Frome in May 2009 and gives an idea of how tall it can get, although it can grow to 5m.

The sap of giant hogweed contains photosensitising furanocoumarins which can cause phytophotodermatitis, or in short, nasty burns to your skin when combined with sunlight, and if it gets in your eyes can result in blindness.giant hogweed

We haven’t found any giant hogweed where we’re based on the North Downs, but we do find it from time to time as we’re out and about.  At this time of year (May) the height of the giant hogweed gives it away, but earlier in spring it isn’t always as obvious.  So here are a few pointers to help tell them apart.


The leaves on giant hogweed tend to be very deeply divided, angular and pointed; they are hairless (glabrous).

hogweed and giant hogweed | foraging | Kent | London | south east

The leaves of common hogweed are more rounded;they are slightly hairy/downy (pubescent).

hogweed and giant hogweed | foraging | Kent | London | south east


Giant hogweed flowers in June and July and has flowers in an umbel up to 50cm across.

hogweed and giant hogweed | foraging | Kent | London | south east

Typically common hogweed flowers from May to August; flowers are in an umbel up to 20cm across.hogweed and giant hogweed | foraging | Kent | London | south east



Giant hogweed has a green stem with distinctive purple blotches.

hogweed and giant hogweed | foraging | Kent | London | south east
Hogweed has a green stem, sometimes with a purple hue.

hogweed and giant hogweed | foraging | Kent | London | south east

 Giant Hogweed  Hogweed
Typically 4m tall before flowering and can reach 5m Typically around 2m tall, but very occassionally can reach 3m
Can reach 10cm in diameter Rarely over 5cm in diameter
 Distinctive purple blotches on a green stem  Purple hue
 Hollow Hollow
 Sharp bristles  Downy, but not sharp

I hope this helps, but remember, if you aren’t 100% certain, leave well alone – don’t risk suffering a potentially painful injury.

You can see loads of photos from our Wildfoods & Woodland Cooking course, along with all of our other courses, on our Facebook page.

About Gary

Lead Instructor at Jack Raven Bushcraft, teaching bushcraft, wilderness and survival skills to groups and individuals.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

7 thoughts on “Hogweed and giant hogweed

  • Pingback: Foraging bike ride: Common Hogweed (Heracleum sphondylium). | monaxle

  • David Brown

    Thank you just started a course at my local nature reserve seen giant hog weed did not know what it was? I know now to keep away from it Thanks for the information.

  • Jean Snaith

    Did not realise how large this grew until I visited the riverside at
    Chester le street last week near cricket ground, huge display. Also
    lots of Dragon Fly wonderful display of colour. DO NOT TOUCH THIS VERY DANGEROUS PLANT