Canadian: Occurs throughout Canada except in NU (Brouillet et al. 2016Footnote 1).
Worldwide: Native to northern Africa, Europe and Asia and widely introduced in North and South America, Australia, New Zealand, and beyond its native range in Africa and Asia (Arabian Peninsula, Southeast Asia) (USDA-ARS 2016Footnote 2).
Duration of life cycle
Annual or short-lived perennial
Seed or fruit type
Seed diameter: 0.8 - 1.3 mm
Seed thickness: 0.8 - 1.0 mm
Round to wedge-shaped seed; tapering at the hilum end; compressed
Covered in tubercles from stellate bases in regular rows following shape of seed
Translucent reddish-brown seed
The hilum is at one end of the seed within a closed notch
Habitat and Crop Association
Cultivated fields, gardens, pastures, lawns, open woodlands, plantations, orchards, roadsides and disturbed areas (FNA 1993+Footnote 3, Darbyshire 2003Footnote 4, CABI 2016Footnote 5). Infests a wide variety of crops (CABI 2016Footnote 5).
Common chickweed has been widely used as a leafy vegetable and medicinal herb (Defelice 2004Footnote 6). It becomes a major pest in cultivation where there is abundant soil organic matter and rainfall (Royer and Dickinson 1999Footnote 7). Due to its shade tolerance it can survive under the crop canopy (Royer and Dickinson 1999Footnote 7).
One plant can produce 750 to 30,400 seeds (Defelice 2004Footnote 6). It is also allelopathic and negatively impacts the growth of wheat (Inderjit and Dakshini 1998Footnote 8).
Field chickweed (Cerastium arvense)
Field chickweed seed is a similar size, rounded shape, reddish-brown colour and tuberculate surface as common chickweed.
Field chickweed seed tends to have a more angular shape, an open notch at the hilum, and is opaque rather than translucent as common chickweed.