Legislation and Info Sheets
1. The Weed Control Act
The Weed Control Act is the Provincial legislation for weed control in Alberta. The Act is administered by the Department of Agriculture, Food and Rural Development. The enforcement of the Act is delegated to local municipalities. This Act over-rides any other legislation dealing with weeds, and the Crown is bound by it.
The purpose of the Weed Control Act is to eliminate existing invasive plant
infestations and limit the introduction and spread of invasive plants throughout the
province. Invasive plants designated as weeds are listed in the Weed Regulation (AR
171/2001) and categorized as restricted, noxious or nuisance.
Although every effort is made to ensure that all information on this webpage is accurate and complete, link to Alberta Legislation (Off-site) for the most current Weed Control Act/Weed Regulation.
For detailed invasive plant information sheets , click on the highlighted species listed below.These documents require Acrobat Reader. If you do not have Adobe Acrobat Reader, the plugin downloader is available for free at:
(Off-site)
Restricted Weeds
Restricted weeds are usually found in small numbers, and are designated as restricted in order to prevent their establishment. Restricted weeds are non-native species that pose a serious threat because of their ability to spread rapidly and out-compete natural vegetation. Section 31(a) of the Weed Control Act states that "owners or occupants of land shall as often as necessary destroy all restricted weeds located on the land to prevent the spread, growth, ripening or scattering of the restricted weeds." Restricted weeds of Alberta are:
(a) Red bartsia - Odontites serotina Dum;
(b) Diffuse knapweed - Centaurea diffusa Lam;
(c) Spotted knapweed - Centaurea maculosa Lam (pdf, 288 Kb);
(d) Nodding thistle - Carduus nutans L. (pdf, 262 Kb); 
(e) Eurasian Water Milfoil - Myriophyllum spicatum L.;
(f) Dodder - Cuscuta spp.;
(g) Yellow star-thistle - Centaurea solstitialis L.
Noxious Weeds
Noxious weeds are generally more abundant than restricted weeds. They have the ability to spread rapidly. Section 31(b) of the Act states that "owners or occupants of land shall as often as necessary control in accordance with this Act and regulations all noxious weeds located on the land to prevent the spread, growth, ripening or scattering of the noxious weeds." Noxious weeds of Alberta include:
(a) Russian knapweed - Centaurea repens L.;
(b) Field bindweed - Convolvulus arvensis L.;
(c) White cockle - Silene alba (Mill.) E. H. L. Krause (pdf, 168 Kb);
(d) Bladder campion - Silene cucubalus Wibel (pdf, 161 Kb);
(e) Cleavers - Galium aparine L. and Galium spurium L.;
(f) Hoary cress - Cardaria spp.;
(g) Knawel - Scleranthus annuus L.;
(h) Perennial sow thistle - Sonchus arvensis L. (pdf, 156 Kb);
(i) Cypress spurge - Euphorbia cyparissias L.;
(j) Leafy spurge - Euphorbia esula L. (pdf, 232 Kb);
(k) Stork's bill - Erodium cicutarium (L.) L'Her.;
(l) Canada thistle - Cirsium arvense (L.) Scop. (pdf, 180 Kb);
(m) Toadflax - Linaria vulgaris Hill. (pdf, 165 Kb);
(n) Persian darnel - Lolium persicum Boiss. & Hohen.;
(o) Scentless chamomile - Matricaria perforata Merat. (pdf, 153 Kb);
(p) Common tansy - Tanacetum vulgare L. (pdf, 225 Kb);
(q) Blueweed - Echium vulgare L. (pdf, 235 Kb);
(r) Spreading dogbane - Apocynum androsaemifolium L.;
(s)
Field scabious - Knautia arvensis (L.) Duby (pdf, 200 Kb);
(t)
Hound's-tongue - Cynoglossum officinale L. (pdf, 196 Kb);
(u) Oxeye daisy - Chrysanthemum leucanthemum L. (pdf, 214 Kb);
(v) Tall buttercup - Ranunculus acris L. (pdf, 176 Kb);
(w)
Purple loosestrife - Lythrum salicaria L.
Nuisance Weeds
Nuisance weeds are common throughout the Province, and are often native species. Due to their abundance and biological suitability, it is difficult to eradicate nuisance weeds. Section 31(c) of the Act states that "owners or occupants of land shall as often as necessary prevent the spread or scattering of nuisance weeds." Nuisance weeds of Alberta include:
(a) Dalmatian toadflax - Linaria dalmatica (L.) Mill. (pdf, 111 Kb);
(b)
Wild radish - Raphanus raphanistrum L.;
(c)
Creeping bellflower - Campanula rapunculoides L.;
(d) Hedge bindweed - Convolvulus sepium L.;
(e) Bluebur - Lappula echinata Gilib;
(f) Downy brome - Bromus tectorum L.;
(g) Tartary buckwheat - Fagopyrum tataricum (L.) J. Gaerta;
(h)
Wild buckwheat - Polygonum convolvulus L.;
(i) Biennial campion - Silene cserei Baumg.;
(j) Night-flowering catchfly - Silene noctiflora L.;
(k) Common chickweed - Stellaria media (L.) Vill.;
(l)
Field chickweed - Cerastium arvense L.;
(m)
Mouse-eared chickweed - Cerastium vulgatum L.;
(n) Rough cinquefoil - Potentilla norvegica L.;
(o)
Cow cockle - Saponaria vaccaria L.;
(p)
Flixweed - Descurainia sophia (L.) Webb;
(q)
Green foxtail - Setaria viridis (L.) Beauv.;
(r) Quack grass - Agropyron repens (L.) Beauv.;
(s) Narrow-leaved hawk's-beard - Crepis tectorum L.;
(t) Hemp nettle - Galeopsis tetrahit L.;
(u) Henbit - Lamium amplexicaule L.;
(v) Lady's-thumb - Polygonum persicaria L.;
(w) Round-leaved mallow - Malva rotundifolia L.;
(x) Ball mustard - Neslia paniculata (L.) Desv.;
(y) Dog mustard - Erucastrum gallicum (Willd.) O.E. Schulz;
(z) Green tansy mustard - Descurainia pinnata (Walt.) Britt.;
(aa)
Wild mustard - Sinapis arvensis L.;
(bb) Wormseed mustard - Erysimum cheiranthoides L.;
(cc)
Wild oats - Avena fatua L.;
(dd) Redroot pigweed - Amaranthus retroflexus L.;
(ee) Shepherd's-purse - Capsella bursa-pastoris (L.) Medic.;
(ff)
Annual sow thistle - Sonchus oleraceus L.;
(gg) Corn spurry - Spergula arvensis L.;
(hh) Stinkweed - Thlaspi arvense L.;
(ii) Russian thistle - Salsola pestifer A. Nels.;
(jj)
Dandelion - Taraxacum officinale Weber.
Additional Invasive Plants
These invasive plants are not currently designated under the Weed Regulation. However, some municipalities have categorized the following as noxious or nuisance:
(a) Black henbane - Hyoscyamus niger (pdf, 228 Kb);
(b) Orange hawkweed - Hieracium aurantiacum (pdf, 157 Kb);
(c) Wild caraway - Carum carvi. (pdf, 210 Kb).
(d) Sulfur cinquefoil - Potentilla recta (pdf, 129 Kb).
2. The Public Lands Act
Of relevance to holders of dispositions issued under the
Public Lands Act is Section 60 of the Act. It states that "a holder of a
disposition shall, with respect to the land contained under the disposition,
use only seed that is free of all restricted and noxious weeds within the
meaning of the Weed Control Act; and cut, keep down and destroy all
restricted and noxious weeds to which the Weed Control Act applies".
Link to Alberta Legislation (Off-site)
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