10:32 AM PDT on Wednesday, May 31, 2006

By GARY CHITTIM / KING 5 News

SEATTLE - A noxious week with a nasty bite is a growing public health threat in Washington’s urban areas.

Giant hogweed looks harmless enough with its broad leaves, delicate flower, and sturdy stalks. That's why people planted them in Seattle decades ago. But this plant can give you a nasty burn.

"You get a blister, kind of a puss filled blister, then after that goes away you a darkened skin a dark purple cherry that can last for several years," said Sasha Shaw of the King County noxius weed control program.

The venom is in the sap. Cut open the stalk and you'll see it. People who try and cut this plant down without protective clothing can get that liquid all over them.

King County

Giant hogweed can grow up to 15 feet tall.

"It's easy for them to get in, they're playing with them, they like to use the hollow stems as a little telescope," Shaw said.

Gardeners are obviously at risk but so are children.

Spencer Wilson has scars that will likely last several years after he played in a patch in the backyard of an old gas station in Seattle's Georgetown neighborhood.

Not only does giant hogweed burn like fire, it spreads like it.

"It had no problem leaping this tall fence and spilling into the alleyway, and if they don't remove it will grow to 15 feet tall and choke this whole alley."

That's why if you see it King County weed fighters want to know about it, and will even help you remove it.

King County property owners who are interested in learning how to identify and control noxious weeds are invited to attend any of the five workshops, set for June and sponsored by the King County Noxious Weed Program.

"Noxious weeds can cause a number of problems for property owners," said Sasha Shaw, King County's noxious weed program education specialist. "Some are poisonous to humans and livestock, and most grow rapidly and are difficult to control."

Weeds can also reduce crop yields, destroy native habitat, clog waterways and diminish land values.

"The hard part is to know where to start and how to tell the weeds apart, and we can teach property owners how to identify the worst invaders and how to prioritize their control," Shaw said.

The workshops, which are free and begin at 7 p.m., feature presentations on pasture weeds and weed management, identification tips with live weed specimens, plus the opportunity for participants to bring unknown weeds and ask questions.

Workshop dates and locations are:

June 8 at Meadowbrook Farm, Snoqualmie;

June 13 at the Covington Library;

June 14 at the Auburn Library;

June 20 at the Enumclaw Library; and

June 27 at the Vashon Land Trust Building, Vashon Island.

To sign up for a workshop, or for more information, contact Shaw at 206-263-6468, or sasha.shaw@metrokc.gov.