The sap from the leaves and particularly the stem is highly toxic and contact with the skin can lead to severe scars. Contact with the eyes can lead to temporary or, in some cases, permanent blindness. The sap renders skin photo-sensitive which means that exposure to sunlight following contact causes blisters and burns.

If you do come into contact with the plant, and especially the sap, you are advised to wash the affected areas immediately, keep them out of direct sunlight and seek medical advice.

How to Recognize Giant Hogweed

• At 8-14 feet high, it is perhaps the tallest herbaceous plant in Pennsylvania.
• Stems are 2-4 inches in diameter, hollow and ridged, with purple blotches and coarse hairs.
• Leaves are sharply and unevenly lobed, approaching 5 feet long.
• Flowering occurs from mid-June to mid-July – flower clusters may reach 2 ½ feet across.
• In winter, dead stems may remain upright, providing an easy means of recognition.
  

Common Sense Methods of Dealing with Giant Hogweed

• DON’T touch of handle plants using your bare hands!
• DON’T allow children to play in hogweed. They may sometimes use the long hollow stems for telescopes or peashooters.
• DON’T transplant Giant Hogweed, plant its seeds or give away plants or seeds.
• DO wash immediately with soap and water if hogweed sap contacts your skin.
• DO report locations of and Giant Hogweed plants.