Prohibited Noxious Weeds

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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, the Vegetation 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 are 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.
 Big Head Knapweed
 Common Barberry
 Common Buckthorn
 Common St John's Wort
 Diffuse Knapweed
 Flowering Rush
Garlic Mustard
 Mouse-ear Hawkweed
 Nodding Thistle
 Orange Hawkweed
 Pale Yellow Iris
 Plumeless Thistle
 Purple Loosestrife
 Salt Cedar
 Spotted Knapweed
 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
 Marsh Thistle
 Meodusahead  Puncturevine  Red Bartsia
 Rush Skeletonweed
 Russian Knapweed
 Saltlover  Scentless Chamomile
 Squarrose Knapweed
 Yellow Nutsedge
 Yellow Starthistle
For more information on these weeds, please check out the fact sheets from the Alberta Invasive Plants Network.
Images provided by Nicole Kimmel, Alberta Agriculture & Forestry.