Hogweed starts to show just after the Anthriscus sylvestris (Cow Parsley) has finished and the main crop is in summer. It does persist until the first significant frosts though. This year (2004) in Cheshire we have had a couple of cold mornings with ice on windscreens and two light ground frosts neither of which is putting of the Heracleum sphondylium. Plants are in healthy full flower (not just hanging on) in December 2004. This is one of the successful roadside herbs and can compete with the luxuriant nettles, docks and thistles as they gobble up the run-off from fields saturated with nitrates and phosphates.

H. sphondylium is found throughout the British Isles and Ireland.

St Abbs Head, Berwickshire, Scotland 14th July 2006

Added on December 16th 2004, updated 6th February 2009, updated 6th April 2010