Giant Hogweed (Heracleum mantegazzianum)

Giant hogweed is a tall (8-20') herbaceous biennial. The plant stays as a basal rosette for several years then when it finally matures it sends up a 2-4" wide hollow stem.

Leaves: 1-5" wide with pointed lobes. Undersides of the leave are covered in coarse white hairs.

Flowers: White, 5 petaled flowers. Blooms in May through July.

Fruits & Seeds: Dry fruits contain a flattened oval seed each.

Roots: Large, deep taproot.

Ecological threats

  • Giant hogweed invades woodland edges, roadsides, but prefers areas with moist soils and shade, such as along streams.
  • It will eventually crowd out native vegetation and increase soil erosion.

CAUTION When sap from giant hogweed contacts skin in presence of sunlight it can cause severe rashes, blisters. Wear gloves, long sleeves, and long pants when handling.

hogweed.jpg   hogweed3.jpg