Giant Hogweed

About Giant Hogweed

Giant Hogweed flowers from mid-June to mid-July. The plant is locally invasive and regrows from cut off rootstock.

Giant Hogweed

Health Risks

  • Clear, watery sap causes reactions to skin and mucous membranes
  • Sap can sensitize skin to sunlight, resembling burns.
  • Potentially fatal reactions have occurred to children playing with hollow stems of plant.
  • Reactions involve mucous membranes, can result in airway occlusion.
  • Burning plants can lead to inhalation of fumes and blister the airways and lungs.
Close-up of Giant Hogweed


  • Parsley and carrot family of plants
  • Height: 6-15 feet
  • Leaves: 2-5 feet in span
  • Stem - 2-4 inches, hollow, colorful, being predominately green with areas of deep purple coloration.
  • The stem, leaf and flower stalks are covered abundantly with hair, most notably at the base of the leaf stalks. Its small white flowers are maintained in wide, flat clusters that may approach 2.5 feet across.

Round up (glysphosate) is effective in controlling hogweed. Wash hads thoroughly with soap and water immediately after contact. Seek medical attention after any contact with poisonous plants.