Agriculture

Weeds

The links below will help you identify the most common weeds found in Manitoba. You can search by common name or family name.

Consult the weed management resources for information on cost-effective control.

Noxious Weeds in Manitoba - Declaration

Weed species in Manitoba are not all created equal. Specific weeds have been designated as 'Noxious' and have been categorized into different tiers based on their significant threat to agricultural primary production. Tier 1 weeds must be eradicated without conditions. Proper identification is important and control measures will depend on the species. Control of Tier 1 weeds is the landowners responsibility (e.g. farmer, company or Governemnt, including Manitoba Highways). The Provincial Mandate to control Noxious Weeds is through the Noxious Weeds Act, but implementation of the Act is at the Municipal or Weed Control District Level. See Manitoba Weed Supervisors Association website and the link to the Manitoba Weed Supervisor Weed Districts map.

Manitoba Noxious Weeds Distribution Maps

The maps below indicate the municipalities where these weeds have been found up to and including the 2024 crop season.

Palmer Amaranth Distribution - 2024

Smooth Pigweed Distribution - 2024

Waterhemp Distribution - 2024

Herbicide Carryover Concerns

Herbicide Carryover Risk

Herbicide Spraying in Hot, Dry Conditions

Weed Control Advice for Dry Conditions - FAQ

Manitoba Weed Survey Results

Herbicide Resistant Weeds - Manitoba 2016

Manitoba Weed Survey - Annual Crops 2016

Manitoba Weed Survey - Annual Crops 2016 Summary poster

Weed Species By Common Name
American Dragonhead Annual Sowthistle Barnyard Grass Bladder Campion Broad-Leaved Plantain Canada Thistle Chickweed Cleavers Cocklebur Common Burdock Common Groundsel Common Milkweed Cow Cockle Curled Dock Dandelion Diffuse Knapweed	Flixweed Foxtail Barley Green Foxtail Hemp-Nettle Kochia Lamb's Quarters Leafy Spurge Narrow-Leaved Hawk's Beard Night-Flowering Catchfly Nodding Thistle Perennial Sowthistle Pineapple Weed Prostrate Knotweed Purslane Quackgrass Red Root Pigweed Round-Leaved Mallow	Russian Thistle Scentless Chamomile Shepherd's Purse Smartweed Stinkweed Stork's Bill Volunteer Barley Volunteer Canola Volunteer Flax Volunteer Wheat White Cockle Wild Buckwheat Wild Mustard Wild Oats Yellow Foxtail Yellow Nutsedge

Amaranth Family

Red Root Pigweed

Buckwheat Family
Curled Dock Prostrate Knotweed	Smartweed Wild Buckwheat

Composite Family
Annual Sowthistle Canada Thistle Cocklebur Common Burdock	Common Groundsel Dandelion Diffuse Knapweed Narrow-Leaved Hawk's Beard	Nodding Thistle Perennial Sowthistle Pineapple Weed Scentless Chamomile