1. Giant Hogweed (Heracleum mantegazzianum) Life history, control and monitoring efforts. By: The Nature Conservancy

2. Life History HabitatHabitat Ravines, roadsides, ditches and riparian areas.Ravines, roadsides, ditches and riparian areas. Residential properties and vacant lots.Residential properties and vacant lots. Wooded or open space areas between residential communities.Wooded or open space areas between residential communities.

3. Morphology Height: 8 – 15ft when in flower Leaves: large, compound, deeply incised, and 3 – 5ft wide. Hairs on the underside are stiff, dense, and stubby but only about.25mm long. Petioles have short course white hairs at the base. Flower head: Flat topped, up to 2.5ft across. Seeds mature in August, distributed summer/fall (water, wind, mowers)

4. Similar species Picture! Cow Parsnip Angelica

5. Safety Extreme skin hazard!Extreme skin hazard! Eye exposure can lead to temporary or permanent loss of vision.Eye exposure can lead to temporary or permanent loss of vision. If exposure does occur wash skin with soap and water, avoid the sun, and seek medical attention.If exposure does occur wash skin with soap and water, avoid the sun, and seek medical attention. When working with plants cover all parts of the body.When working with plants cover all parts of the body.

6. Control Difficult to control due to photo- toxicity. (ie. Contact with plants sap and exposure to UV light will cause severe blistering) Hand-digging Repeated mowing, weakens plant but large roots will remain alive for years. Herbicide sprays, a foliar treatment of glyphosate or triclopyr. (Has been effective in the Pacific Northwest).

7. Monitoring

8. Other sightings?