Invasive Species: Giant Hogweed

Heracleum mantegazzianum

Giant hogweed is noted for its gigantic leaves and towering stature when mature.

Why is it important to control?

This plant poses a health hazard to humans. Its sap sensitizes skin to ultraviolet light and can cause serious burns and even blindness.

How can you identify it?

Close up image of red blotching on giant hogweed stemImage of giant hogweed flowers and seed heads
Habitat: Forests, riparian areas, and wetlands.
Life Cycle: Perennial
Height: Rosettes to 4 feet; flowering stems to 20 feet.
Leaf Description: Leaves can be up to 5 feet wide, with three deeply cut leaflets.
Fruit & Flower Description: Tiny white flowers arranged in a flat topped cluster.
Bloom Time: May to July

How do you control it?

  • Do NOT treat this plant yourself! Contact Yamhill SWCD.

How to report it?

There are various ways you can report this noxious weed.