Giant hogweed is one nasty plant - July 14, 2002

Mail Tribune (Medford, OR — Wayback)

2002-07-16

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SUNNY Temp: 61 °F Wind: CLM at 0 mph Tuesday, July 16, 2002  SECTIONS   Home Page   Local News  Sports  Business  Obituaries  Life  Opinion - Politics  AP News  Weather  Classified  Archives  Site Map  EXTRA  Cyberchef  E The People  Golf  Job Network  Headbone Zone  Wellness Connection  Movie Times  Newspaper in Education  Oregon CarZone  Outdoor Journal  Personals  Prime Times  Real Estate  Tempo A & E  TV Times  W3 Magazine  CLASSIFIEDS  Find a Car  Find a Home  Find a Job  Find Everything  E SOUTHERN OREGON  Destinations  Automotive  Communities  Employment  Entertainment  Publications  Real Estate  Recreation  Shopping  Calendar  ABOUT US  FAQ  What's New  Advertise  Home Delivery  Classified Ad  Contact Us  Media Kit  Jobs @ Mail Tribune Email Story to a Friend July 14, 2002 Giant hogweed. Click the photo to see a larger (35k) version; use your Back button to return to the story. Don’t touch the plants The Oregon Department of Agriculture has posted photos of giant hogweed at www.oda.state.or.us in hopes of avoiding a rash of mistaken identity calls. The best way to identify giant hogweed, which can look a lot like the cow parsnip, is its purple stems, the ODA’s Tim Butler says. Hogweed can grow to 15 feet. Cow parsnip grows to 8 feet, and it has green stems. If you do think you’ve found a hogweed, you can call ODA officials at (503) 986-4621. Anybody cutting down giant hogweed should wear gloves and protective clothing. Seed heads should be burned or taken to a landfill, not put into compost heaps where they may survive the heat. Hogweed can be treated with the herbicide glyphosate, which should be applied during bud stage and while the plant is growing. But the best cure is prevention. "Don’t move plants if you don’t know what they are," says George Tiger of Oregon State University Extension Service. "If in doubt, leave it." Giant hogweed It’s 15 feet tall, with a 5-foot leafspan. It can leave you vulnerable to ultraviolet light. And it’s spreading By BILL VARBLE Mail Tribune The advance of a giant, people-menacing plant out of Asia sounds like science fiction. But with giant hogweed widespread in Portland and reaching as far south as Eugene, could the Rogue Valley be next? "The good news is there’s none down your way," says Tim Butler, who manages the noxious weed control program of the Oregon Department of Agriculture in Salem. So far. The giant hogweed, Heracleum mantegazziamum, is an ugly customer indeed, causing burning, blisters, intense itching and sometimes permanent scars. It’s an intimidating specimen, growing 15 feet high with leaves up to 5 feet across. It flowers from the middle of May through July. The stem is up to 4 inches thick, warty and pocked with blisters, each of which sprouts an individual hair. "It looks like a cow parsnip," Butler says, "but much larger." Hogweed produces a clear, watery sap that sensitizes its victim’s skin to ultraviolet radiation, resulting in painful burns. Acute symptoms include purple blisters up to 5 inches across that can last a week and leave black and purple scars. Giant hogweed was found at four sites in Oregon a year ago and has now been identified in 50. A member of Umbelliferae, a group of plants with cauliflower-like heads, it is on the state’s A list of weeds that occur in small numbers and are targeted for eradication, and on a similar federal list. George Tiger of the Oregon State University Extension Service hasn’t seen hogweed, but he says people bring noxious weeds to the county all the time. "They say they got it in Eastern Oregon or Washington, and they think it looks neat," he says. Tiger says people have brought in poison hemlock, noxious whitetop and even poison oak. "It’s usually the uninformed," he says. "It’s not the master gardeners." Native to the Caucasus of southwest Asia, giant hogweed was introduced to England in the 19th century and spread by gardeners who found it exotic and showy. It escaped the British Royal Botanic Gardens at Kew in the early 1900s. English garden journals listed it as a showy ornamental until the 1960s, when it was linked to rashes and scarring. It came to Canada, Pennsylvania and Washington, where it’s been found at more than 800 sites. Once it gets started, giant hogweed can take over, especially in riparian zones and ravines. Seeds are too heavy to be spread by the wind, although they can be carried downstream in creeks and rivers. "Gardeners have told us they thought it was neat," Butler says. When plants are identified, Butler works with landowners to eradicate it. It is illegal to sell the plant. Giant hogweed is the latest in a long list of invaders spreading into Oregon, including English ivy, Scotch broom and more recently small broomrape, a threat to the clover industry, and kudzu, a viny scourge formerly not known west of Texas. Is giant hogweed headed for Southern Oregon? "You can’t say it won’t show up, but it would be a big jump," Butler says. "People don’t need to panic." Printer Friendly Version   Email Story to a Friend Subscribe Archive: Click to Search Mail Tribune Home Local News  | Sports  | Business  | Obituaries  | Life Opinion - Politics | AP News | Archives  |  Site Map   E Southern Oregon  | Classified   Copyright 1997-2002 Mail Tribune. All rights reserved. Privacy Policy web master feedback A D V E R T I S E R S