Weed Control: Who Do You Call?


Weed control legislation has a long history in Ontario. The province first introduced legislation in 1866 to prevent the spreading of thistles. Later legislation introduced in 1884 was intended to prevent the spreading of noxious weeds and fruit tree diseases.

Today, the Weed Control Act is designed to provide relief from the spreading of noxious weeds. The act states that, "every person in possession of land shall destroy all noxious weeds on it." By regulation, the province has designated the following 23 plants as noxious weeds:

Municipalities may add to this by bylaw for local enforcement.

Q: Who oversees weed control?

A: There are four levels of weed inspectors. Township councils or cities appoint one or more weed inspectors at their discretion. There are also area weed inspectors and district weed inspectors.


Bull Thistle
Canada Thistle
Colt's Foot
Common Barberly
Cypress Spurge
European Buckhorn
Goat's Beard
Johnson Grass
Leafy Spurge

Nodding Thistle
Perrennial Sow Thistle
Poison Hemlock
Poison Ivy
Proso Millet (black seeded)
Russian Thistle
Scotch Thistle
Tuberous Vetchling
Wild Carrot
Yellow Rocket

A chief weed inspector is appointed by OMAFRA.

A landowner concerned about weeds on neighbouring lands should contact the municipal clerk and ask for the weed inspector.
The local municipal clerk should always be the first point of contact, regardless of whether the weed problem occurs at the municipal, county or provincial levels. The clerk will contact the appropriate inspector.

Q: What powers do weed inspectors have?

A: Weed inspectors have the authority to enter lands and buildings, except dwellings, to look for noxious weeds or weed seeds. Their entry powers include implements, machinery, vehicles and crops - in addition to land and buildings. If inspectors are denied entry or access, they can apply to a justice of the peace for a warrant to carry out their duties.

All weed inspectors have broad enforcement powers under the act, which include abandoned railway rights of way and MTO properties.

When a weed inspector finds noxious weeds or weed seeds, he can order the person in possession of the land to destroy them within seven days (excluding weekends).

An order to destroy weeds can be appealed to the chief inspector. In turn, the decision of the chief inspector can be appealed to divisional court.

Q: What happens if a landowner doesn't comply?

A: If a landowner fails to obey an order to destroy, the municipality can destroy the weeds and bill the owner for the cost. Ultimately, if the bill is not paid, it is added to the property tax bill as taxes owing.

Orders to destroy weeds can be given to a municipality for lands under their jurisdiction.
Sections 19 through 22 are key to the Weed Control Act. They state that:

19. No person shall deposit or permit to be deposited any noxious weeds or weed seeds in any place where they might grow or spread.

20. If the moving of a machine used for agricultural purposes is likely to cause noxious weeds or weed seeds to grow or spread, no person shall move the machine or cause it to be moved without first removing from it all seeds and other residue.

21. A person in charge of a grain elevator, seed-cleaning plant or other grain-cleaning or grain-grinding shall dispose of all refuse containing weed seeds in a manner that will prevent them from growing or spreading.

· Sections 3 (duty to destroy weeds), 13 (order to destroy weeds), 16 (destruction of weeds) and 18 (notice requiring destruction), do not apply to noxious weeds or weed seeds that are far enough away from any land used for agricultural or horticultural purposes that they do not interfere with that use.

The intention of the act is to protect agriculture and human health and it is not to be used as a "defacto" property standards bylaw.

Q: How should weeds be destroyed?

A: Regulations under the Weed Control Act describe how weeds are to be destroyed. The authorized methods include:

  • pulling up the weeds;
  • cutting before the seeds have developed enough to ripen after cutting;
  • where the seeds could ripen, the seeds are to be removed from the property, composted, used as animal feed, ground, crushed or burnt.
  • plowing or cultivating the soil where they are growing;
  • applying a herbicide that will prevent weed growth or seed ripening.

If herbicides are chosen, only approved products can be used.

Submissions & Correspondence

OFA letter regarding Wild Parsnip
(September 2, 2016)


Weed control must be taken seriously
(July 22, 2016 - Weed & Pest Management, Weed Control: Who Do You Call?)

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