Invasive plant species

Report invasive species

Giant Hogweed and Dog Strangling vine are two invasive plant species that have just begun to appear in Guelph. We’re doing what we can to detect it early and remove it to prevent spreading, but we need your help in reporting any sightings!

Do not touch giant hogweed

Identify giant hogweed

  • Tall, thick stem with reddish spots that stands 10 to 15 feet high
  • Umbrella-shaped white flower head with a flat top
  • Often mistaken for Queen Anne’s lace, cow parsnip and angelica; giant hogweed is much larger

Get rid of giant hogweed

The safest way to get rid of giant hogweed is to call a professional service. If you must remove it, follow the proper safety protocols.

  1. Wear protective clothing including gloves, pants, long sleeves, eye protection, rain coat and boots
  2. Remove flower heads to prevent seeds from growing
  3. Cut plant roots 3-5 inches below the soil
  4. Throw away the plant in a double-bagged garbage bag, sealed. Do not compost.
  5. Wash the clothes you wore during removal
  6. Watch for any new growth and remove as needed

Giant hogweed is an invasive plant originally from Asia. The sap of giant hogweed is dangerous to the skin, causing inflammation, burns and possibly blindness if it comes into contact with the eyes.

Dog Strangling Vine

A photo depicting the leaves of dog strangling vine. They are long, dark green and oval, coming to a sharp point. The flowers are a light pink and look like tiny stars.

Photo by R. A. Nonenmacher

Identify dog strangling vine

  • Grows one to two metres high, twining on to other plants and trees
  • It’s leaves are shiny, yellow-green and dark green in the shape of ovals with a pointy tip
  • Produces pink or purple star-shaped flowers with five petals in late June
  • Produces bean-shaped pods that are four-seven centimetres long that open to release feathery white seeds in late summer

Get rid of dog strangling vine

  1. Cut at the base
  2. Throw it in the garbage, not your compost!
  3. Do not let it flower or seed

Dog strangling vine is an invasive species from Europe that is spreading rapidly throughout Ontario. This plant species smothers native plants and young trees and impacts wildlife by reducing habitats for birds, pollinators and insects and increases wildlife grazing on native species.


Ontario’s Invading Species Awareness Program
Stop the spread of invasive species