Identifying giant hogweed

Giant hogweed:

  • bears a close resemblance to native cow parsley and hogweed 
  • has a reddish purple stem with fine spines that make it appear furry (like a stinging nettle)
  • has spotted leaf stalks
  • may grow to 3-5m high
  • leaves can be up to 1.5m wide
  • plants can take up to four years to reach their full height and flower
  • flowers in June and July
  • flower heads are commonly 500mm (0.5m) wide
  • flowers can each produce 50,000 seeds every year
  • seeds can stay in the soil for up to 15 years before they develop.

In this guideline: