A Carrot Even Bugs Bunny Wouldn't Like
6/17/2009

SALEM, Oregon—You would think a giant member of the carrot family would be something a rabbit would dream about, but Giant hogweed has few friends, and unfortunately, no natural enemies in Oregon.

The Oregon Invasive Species Council June 2009 Invasive Species of the Month, featured online at www.oregon.gov/OISC, is a member of the carrot or parsley family, is native to Asia, and grows 10 to 15 feet tall. It found its way to northwest Oregon in 2001, where land managers are mounting a full frontal assault to eradicate the species in areas such as wetland and agricultural field edges, river corridors, forests, recreation areas, and neighborhoods.

Because of its invasive nature, Giant hogweed readily becomes a pest and outcompetes native vegetation. The plant is also a public health hazard because the sap causes skin to be more sensitive to the sun, resulting in second degree burns. The photosensitive effects can remain for several years, resulting in seasonal burns and scars.

The good news is that if Giant hogweed is detected early, mechanical and chemical treatments can kill the plant. Sites are monitored for five years to ensure any seeds the plant may have produced do not have an opportunity to grow and become established.

“Early detection and rapid response (EDRR) to infestations increases the potential successful eradication of hogweed,” said Oregon Department of Agriculture (ODA) Noxious Weed Control Program Manager Tim Butler. “Our goal is to detect infestations when they are small while they are more easily controlled. EDRR efforts also make sense economically—for every dollar spent, you can gain $33 in benefits.”

How important is it for the public to watch for Giant Hogweed? Oregon Department of Agriculture Plant Division Administrator Dan Hilburn says it is critical. “In Oregon, we're lucky that Giant hogweed was recognized as a weed before it got out of hand,” said Hilburn. “With the help of the public, we have the chance to completely eradicate this weed from the state."

Vern Holm, Northwest Weed Management Partnership Coordinator, agrees that public education and involvement is critical to managing invasive species. “Thanks to Oregon Public Broadcasting’s The Silent Invasion program and ongoing outreach by the Oregon Invasive Species Council and many other organizations throughout the state, more and more patches of Giant hogweed are being reported,” said Holm. “Also, early detection workshops, designed to teach the public how to identify new invaders, has resulted in a network of individuals with identification skills, which has provided important information about the distribution of Giant hogweed. Thankfully, plants that are detected are plants that can be controlled."

ODA has been monitoring 52 hogweed sites in the City of Portland. In 2008, over 1,250 Giant hogweed plants were removed. This year, ODA rolls up its sleeves with the City of Portland to continue this invasive plant removal project.

If you see giant hogweed, report it immediately at 1-866-INVADER or www.oregoninvasiveshotline.org. Remember, early detection is the key to keeping invasive species at bay.

And watch for the July’s Invasive Species of the Month, the “bug-eyed” emerald ash borer.

The mission of the Oregon Invasive Species Council is to conduct a coordinated and comprehensive effort to keep invasive species out of Oregon and to eliminate, reduce, or mitigate the impacts of invasive species already established in Oregon.