The weeds in the prohibited noxious class are those which are known to pose an intolerable economic threat to production, recreation or the general environment, and the degree of infestation is such that eradication is physically and economically feasible.

When prohibited noxious weeds are involved, theVegetation Management Technicians are obligated to inventory the designated species, to map the locations and issue a notice to destroy. The Vegetation Management Technicians are to advise the Director of Agricultural Services and then monitor the site regularly to ensure that the directives of the notice are carried out. If there is non‑compliance, he will be obliged to contact the Director of Agricultural Services so as to initiate legal action or cause the work to be done and have all costs charged against the land or person involved. Further, continued surveillance by the Vegetation Management Technicians can be anticipated for several years to ensure that there is no recurrences of growth of the weed.

The Weed Control Act stipulates that a person shall destroy a prohibited noxious weed that is on land the person owns or occupies.

Prohibited Noxious Weeds:


Big Head Knapweed

Big Head Knapweed

Common Barberry
Common Barberry

Common Buckthorn
Common Buckthorn

Common St Johns Wort
Common St John’s Wort

Diffuse Knapweed
Diffuse Knapweed

Flowering Rush 2
Flowering Rush

Garlic Mustard
Garlic Mustard

Mouse Ear Hawkweed

Mouse-ear Hawkweed

Nodding Thistle
Nodding Thistle

Orange Hawkweed
Orange Hawkweed

Pale Yellow Iris
Pale Yellow Iris

Plumeless Thistle
Plumeless Thistle

Purple Loosestrife
Purple Loosestrife

Salt Cedar

Salt Cedar

Spotted Knapweed

Spotted Knapweed

Sulphur Cinquefoil
Sulphur Cinquefoil

Autumn Olive
Dodder
Dyer’s Woad
Eurasian Water Milfoil
Giant Hogweed

Giant Knotweed
Himalayan Balsam
Hoary Alyssum
Japanese Knotweed
Jointed Goatgrass
Leafy Spurge
MarshThistle
Medusahead
Puncturevine
Red Bartsia
Rush Skeletonweed
Russian Knapweed
Saltlover
Scentless Chamomile
Squarrose Knapweed
Tansy Ragwort
Tyrol Knapweed
Yellow Nutsedge
Yellow Starthistle

For more information on these weeds please check out the fact sheets from the Alberta Invasive Plants Network.

What to do if you find any of these plants in the County of Newell?


Please notify the County of Newell Director of Agricultural Services. We can than work with the landowner to find a solution to remove this weed and keep it from spreading and establishing in our County.

Images provided by Nicole Kimmel, Alberta Agriculture & Forestry.