Invasive Species Spotlight: Giant Hogweed
Guest post by Jacqueline Hyman
Don’t let the pretty bunches of white flowers fool you – Giant Hogweed is a toxic plant that should not be reckoned with, according to Plant Invaders of the Mid-Atlantic.
Giant Hogweed originated in Europe and Asia and was introduced to the U.S. in 1917 as an ornamental plant, according to Plant Invaders.
Giant Hogweed is a biennial plant in the parsley family that grows up to 20 feet high with a hollow stem with flowers that occur in late spring to early summer, according to Plant Invaders. The book says that the plant “grows well in a variety of habitats but prefers moist, rich soils in disturbed areas such as riverbanks, ditches and railroad right-of-ways.”
The stems, according to the University of Maryland Extension, have purple blotches, and the leaves are serrated and pointed.
According to UMD Extension, the plant is taller and has a thicker stem than its lookalikes, such as wild parsnip, poison hemlock, and Angelica. It has been identified in western and central Maryland, Washington DC, and several other states on the east cost as well as throughout the U.S. The seeds can produce for up to seven years in soil, but most will germinate after three years.
This plant is a problem because “it goes beyond the standard practice of taking over native habitats and crowding out the sources of food and cover that our native wildlife species depend upon,” according to the extension’s website page about Giant Hogweed. The plant also shades out “all competition, creating bare earth and an erosion hazard,” the website notes.
Most importantly, the plant is actually extremely toxic. Plant Invaders advises to never touch the plant, because its sap causes skin sensitivity to ultraviolet radiation and “leads to blistering and severe burns.”
The increased sensitivity is worst in the first two hours after contact with the plant, and can even last for years afterward, according to UMD Extension.
Anyone who sees the plant should call the state Department of Agriculture in order to request assistance with control of the plant, notifying the department of its exact location, Plant Invaders recommends. Do not attempt to remove Giant Hogweed without help, and be sure always to keep covered in areas where you may encounter the plant.
The "Invasive Species Spotlight" is a summer blog series focusing on a different plant each week that is a problem for Mid-Atlantic home gardeners.
About the author:
Jacqueline Hyman is a junior journalism and English major at the University of Maryland. She is the editor-in-chief of the Mitzpeh, an independent Jewish newspaper at UMD. In addition, Jacqueline enjoys musical theater, and teaches piano and voice at Guitar Center. She is excited to be interning this summer for the Washington Gardener.