Giant hogweed is a large pant native to Asia that has made its way around the world. It can grow 15-20 feet (4.5-6m) tall with a stem that has a diameter of 2-4 inches (5-10cm). The leaves of a giant hogweed plant grow to about 5 feet (1.5m) in width. Giant hogweed has lacy, white umbel flowers that can reach a diameter of 2 ½ feet (0.7m).

Giant hogweed was introduced into the United States around 1917 as an ornamental garden plant. It has escaped cultivation and become well established in many parts of the country. It is found abundantly in the western part of New York State, Connecticut and Massachusetts. It also flourishes on the west coast of the United States in Oregon and Washington, as well as in Canada and throughout Europe.

Giant hogweed is very adaptive and can thrive in a wide range of habitats. It lives on river banks, near streams, on roadsides, in vacant lots, in yards and gardens or in any other cool, wet areas. Hogweed spreads fairly slowly, but persistently.

Giant hogweed is very dangerous to humans. It secretes a clear toxic sap which makes the skin very sensitive to ultraviolet (UV) rays. Contact with the sap of giant hogweed quickly results in painful blisters, third degree burns and permanent scarring. If giant hogweed comes in contact with the eyes, it can cause temporary or sometimes even permanent blindness. Giant hogweed is especially dangerous to children, who are attracted to areas where this plant likes to grow. Its large hollow stalk is appealing to some for makeshift weapons and pea shooters.

Giant hogweed is hazardous not only to humans, but also to the environment. As an invasive species, giant hogweed destroys native plants and disrupts ecosystems by competing with other plants for sunlight, space and nutrients. This in turn affects animal life by reducing the food supply derived from native species of plants.

When the giant hogweed plant dies in the fall, it contributes to soil erosion along river and stream banks where it grows. Since it replaces native species whose roots normally remain and hold the soil in place, giant hogweed causes the soil it grows in to easily wash away. Giant hogweed also contributes to wind erosion in some of its habitats for the same reason.

In the United States, giant hogweed is on the federal government’s noxious weed list and further imports of this plant are illegal. It is also illegal to transport the plant from state to state or even within a state. Besides trying to prevent further introduction of the plant, attempts to control giant hogweed include the use of herbicides and mechanical removal, which are only minimally effective due to the plant's hardiness and adaptive capabilities.