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Giant hogweed, an invasive, noxious weed with a sap that can cause painful blisters, even blindness, if it comes in contact with the eyes.

How to identify giant hogweed:

Giant hogweed – growing 3 to 4 metres in height and when in bloom, carries numerous small, white flowers that form an umbrella shape.

It looks like a colossal version of Queen Anne’s lace, or wild carrot and is often mistaken for angelica or cow parsnip because of its similar leaf pattern.

Giant hogweed is most commonly recognized by its flowering stalks, the plant blooms in mid-May through July.    The plant is a perennial, meaning it returns every spring.

Since arriving in Ontario, the plant has spread quickly, taking advantage of local waterways, including those in the Grand River watershed, to carry its particularly buoyant seeds.

What to do if you spot giant hogweed:

If you find the plant in your backyard,  it is recommended that you remove it.   The weed is a public health hazard and is dangerous to both children and pets.

The city advises people to wear protective clothing, including gloves and eye protection to avoid getting the sap on their skin or in their eyes.

People are told to remove the flowering head in order to stop the spread of the plant’s seeds and sever the plant’s roots, 8 to 12 centimetres below the surface of the soil.

When disposing of the plant, seal what’s left of the weed in a double-bag.  Any seeds left behind can germinate for up to 15 years after the parent plant has been killed.

How to treat giant hogweed burns:

Giant hogweed, if encountered in the wild, should be left alone.  “Stay away from it,”. If your skin comes in contact with the weed, wash any affected areas immediately with soap and water.  Keeping any affected areas of skin out of direct sunlight and seek medical advice as soon as possible.