Problem Weeds

The weeds designated as noxious and prohibited noxious under the Alberta Weed Control Act spread rapidly and can outgrow native species resulting in an impact on natural environments.

In 2010, several plants were added to the noxious and prohibited noxious weed lists under the Alberta Weed Control Act, including a number of invasive ornamentals. Many of the new species can be found growing in flower beds or gardens.

Noxious Weeds

Noxious weeds must be controlled to prevent the spread of seeds and prevent the plants from being established. They can be controlled by hand-pulling, mowing, cultivating or spraying them with an appropriate herbicide.

The information sheets below are in PDF format.

• Broad-leaved Pepper-grass
• Common Mullein
• Downy Brome
• Japanese Brome
• Canada Thistle
• Common Tansy
• Scentless Chamomile
• Leafy Spurge
• Perennial Sow Thistle
• Oxeye Daisy
• Hoary Cress
• Common Burdock
• Blueweed
• Tall Buttercup
• Black Henbane
• Baby's Breath
• Hounds Tongue
• White Cockle
• Common Toadflax
• Creeping Bellflower
• Dalmation Toadflax
• Dames Rocket
• Field Bindweed
• Field Scabious
• Yellow Clematis

Prohibited Noxious Weeds

Prohibited noxious weeds must be destroyed by eradicating all growing parts of the plant or to render the reproductive mechanisms unviable. Prohibited noxious weeds can be destroyed by hand-pulling, cultivation or mowing followed by an application of an appropriate herbicide. Dispose of prohibited noxious and noxious weeds in a manner that will prevent the spread of the weed seeds.

The information sheets below are in PDF format.

• Jointed Goatgrass
• Meadow Hawkweed
• Red Bartsia
• Tansy Ragwort
• Yellow Flag Iris
• Nodding Thistle
• Diffuse Knapweed
• Spotted Knapweed
• Yellow Starthistle
• Orange Hawkweed
• Eurasian Watermilfoil
• Garlic Mustard
• Sulphur Cinquefoil
• Russian Knapweed
• Salt Cedar (aka Tamarisk)
• Himalayan Balsam
• Purple Loosestrife

While all prohibited noxious and noxious weeds are targeted by Agricultural Services for removal in the county, the main weeds of concern in Rocky View are Canada Thistle, Perennial Sow Thistle, Toadflax and Scentless Chamomile.

Tip: Avoid Wildflower Mixes

• Wildflower mixes often contain invasive plant species that spread rapidly and are not from the local area.
• Make sure to check the label for the Latin names to know exactly what you are planting in your garden and flower beds.
• Avoid purchasing seed mixes that do not include Latin names on the label.
• If you would like to plant wildflowers, it is best to research native wildflower species, common to your area, and plant individual flowers or purchase seed mixes from local reputable growers.