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

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Invasive Plant Best Management Practices for Landowners

1. A permit must be obtained from the Adirondack Park Agency if the invader to be controlled is located in or within 100 ft of a wetland on public or private land.

2. Private property owners are allowed to apply general use herbicide products (Roundup Pro Max, and Roundup Pro Concentrate) on their own property for invasive species control. In all instances the herbicide product label is the law and must be read and followed accordingly.japaneseknotweed

3. All herbicide applications in or around surface waters or wetlands should be made by a New York State certified pesticide applicator.

4. Spot treatments to individual plants using a back pack or hand sprayer, wick applicator, cloth glove applicator, stem injection system, herbicide clippers, etc. are allowed for use during herbicide applications.

5. During manual management, bag all plant material in a heavy duty garbage bag and leave outside in the sun for a couple weeks. Dispose of bags in a landfill. For woody invasive shrubs, excavate or dig up while not in fruit, and dry with roots propped upwards for a few weeks. Burn dead material or use to construct brush piles for wildlife habitat improvement.

6. To prevent the spread of invasive plants, manage when plants are not in seed. All management equipment should be thoroughly rinsed off with water before the next use.

7. If you have removed invasive plants from your property and would like to replace them with native alternatives, contact the Hamilton County Soil and Water Conservation District for recommendations.

8. Be persistent as plants may grow back. For larger infestations, complete elimination may take several years of consistent management.

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