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How to identify giant hogweed, what to do if you encounter them explained in this video.

How to avoid a painful run-in with Giant Hogweed

Hailey Montgomery
Digital Reporter

Friday, June 2, 2017, 1:46 PM - Springtime in Canada marks the return of a highly resilient, perennial invasive plant species that is both a public health risk and a threat to Canada’s native diversity.

Plans to control the plant are in the works, following frequent sightings across the country, where it has shaded out native plant species and caused human skin to break out into painful, blistery rashes.

A giant hogweed will reach maturity and flower in the summertime, then becoming more dangerous and difficult to remove. At any height, it is safest to avoid the plant completely.

Here's what you need to know in case you spot a giant hogweed in your area:

What does giant hogweed look like?

Giant Hogweed can grow to 2.5 to 4 m (8 to 14 ft.) tall, with leaves up to 1 metre wide. Once the plant is full grown, it will bloom large (30 cm in diameter), white flowers. Its stem is covered in coarse hairs and purple spots. 

Queen Anne’s lace is a common lookalike, but is much shorter and completely safe. 

What should I do if I encounter giant hogweed? 

Conservation Halton in Oakville, ON, advises that you do not attempt to remove a giant hogweed yourself. If you encounter the plant in nature, then simply leave it alone. If you see the plant on your property, it is best to call a professional, especially if the plant has flowered. If you do choose to remove the plant yourself, you MUST completely cover your skin with protective waterproof clothing. You should also wear goggles and rubber boots.  

If you touch the plants, try not to expose your skin to sunlight. Immediately rinse the skin with water and soap. If you do develop a rash, seek medical attention.

You may also report a Hogweed sighting to your local conservation authority.

Where is giant hogweed found?

Giant hogweed typically thrives near the floodplains of creeks and rivers. It has been spotted across Canada.

Why is giant hogweed dangerous to our health?

Giant hogweed sap contains a noxious chemical that makes our skin unable to protect itself from the sun. The toxic sap, combined with sunlight, can make the skin break out into a reaction resembling a third-degree sunburn. The burn causes large, liquid-filled boils, and is said to be painful and itchy.This reaction, known as photosensitivity, could appear two-to-three days after the skin is exposed to the hogweed sap.

Where did giant hogweed come from? 

Giant hogweed is believed to have been brought to Canada from the mountainous regions of southwest Asia. It was planted in gardens decoratively, because of it’s unusual appearance and large flowers. It still thrives in parts of Asia and Europe.

How does it spread so quickly?

When the hogweed matures and flowers, it can produce up to 120,000 winged seeds. The seeds travel in the air and in rivers and creeks, and can survive for days.

Sources: Conservation Halton | The Government of Ontario | The University of Guelph | Ontario's Invading Species | [Thumbnail Credit]

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