Noxious Giant Hogweed Plant, in Waterloo Region

Mark Bauman was walking near the St. Jacobs dam when he spotted a big, "neat looking plant" that would look nice his garden.

So he dug out one and planted it near his house. Only later, when it had to trim back the spreading crop, did he realize it wasn't all that pretty.

"I actually got some burns on my hands," said the Woolwich Township councillor.

Within a day or so, the giant hogweed sap caused dime-sized, brown blisters to well up on his hands as he worked out in the sun. "It looked like a second-degree burn."

There was pain, but it wasn't overwhelming, he said. Eventually, they cleared up without leaving scars.

"I didn't know what it was. That's when I started looking at what it was and found out."

Giant hogweed was transplanted from China to England, for use in ornamental gardens. It's smothered Britain, spread across Europe and is now in the U.S. and southern Ontario.

Bauman didn't initially find widespread concern about the plant. That changed about five years ago, as people started raising alarms as more started turning up in the area. The more Bauman talked about it, the more people mentioned they've seen it around for years here and there.

Giant hogweed develops pods containing upwards of 10,000 seeds. The plant likes wet soil along waterways, where it drops pods into the water to spread seeds downstream.

"The Grand River doesn't know boundaries. It's going to follow the watercourses," Bauman said.

Bauman pressed Woolwich and Waterloo Region councils to act on the growing nuisance that spoils crops, sickens livestock and in extreme cases, disfigures and blinds humans.

Last year, regional council added giant hogweed to the local list of "noxious weeds." That means weed inspectors can order land owners to destroy it on sight. If they don't, eradication crews can be ordered in and the cost added to the landowners taxes.

Upwards of 1,500 plants were destroyed near the St. Jacobs dam three years ago, said Larry Martin, the region's weed inspector.

He's already had dozens of calls about hogweed this year, and expects many more before frost hits.

"It's just seems to be cropping up all over the place," he said.

Some calls are about sightings of a look-alike Angelica, which has smaller white flowers. But it doesn't tower four to five metres like giant hogweed.

Grand River Conservation Authority crews are fighting hogweed across the watershed, from Belwood to land near Guelph Lake to a plant found this year along a trail in Cambridge's Shade's Mills Conservation area.

Kitchener firefighters were told this month to be wary of the plant along rural watercourses in the city.

City of Waterloo crews have discovered the plant in Kaufman flats near the Grand River, Bechtel Park and Rolling Hills Park in the Lakeshore part of town.

"It's not in epidemic proportions, but it's creeping into the area," said Len Fay, Waterloo's manager of forestry and horticulture.

Since Waterloo is a "pesticide free community," city crews have to "go in and cut it out," he said.

What to watch out for:

Plant can grow up to five metres tall with an umbrella of white flowers nearly a metre across. The hollow stems can be up to 10 cm in diameter, with white hairs and red-purple colouring. The leaves can spread nearly two metres across

Avoid the clear sap, which causes skin to become sensitive to sunlight, causing nasty chemical burns

If exposed to the sap, avoid sunlight, don't touch your eyes and wash thoroughly with soap and water

Get medical help if blisters form

Contact with eyes can cause temporary or permanent blindness

Sap can also produce painless red blotches that later develop into purplish or brownish scars that may persist for years

Seeds can lie dormant up to seven years, so expect years of work to eradicate the plants from an area

Wear eye protection, gloves and rubberized overalls if you try to cut it or spray herbicides; calling a contractor is safer

Don't use power tools to cut it or burn the plants; sap will spread in the air

Give hogweed a wide berth and report it to your township or city hall if you find it.

Info: www ontarioweeds.com or region weed inspector 519-575-4016.

This article courtesy: The KW Record