logo150 Hamilton County Soil & Water Conservation District  

Giant Hogweed

Hamilton County Distribution

  • Confirmed in Speculator in 2013. The site was eradicated and monitoring continues.


  • Hairy, green stems have purple blotches
  • Small white flowers grow in clusters shaped like an umbrella that can span 2.5 feet
  • Flowers bloom in June or July
  • Leaves are lobed and large, often reaching 5 feet.
  • Look-alikes (pdf)


  • Public health and safety
  • Sap reacts with sunlight and moisture (sweat) and can cause blisters, burns, scaring, or blindness.  Children pretend hollow stems are flutes, swords, or telescopes, and may be harmed by the sap.  People may encounter sap if they brush up against broken vegetation
  • Out-compete native plants for sunlight and growing space
  • Wildlife may lose a food source
  • Shallow roots are not as affective at holding soil in place as native plant roots, and soil erosion may occur


  • Never touch this plant. Contact the District if you think you spot giant hogweed: This email address is being protected from spambots. You need JavaScript enabled to view it., 518-548-3991

  • a
  • b
  • c
  • d
  • e
  • f
  • h
  • i
  • j
  • k
  • m
  • n

The District’s accomplishments would not be possible without the support of the State of New York, Hamilton County, and FLLOWPA.