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Ministry of Agriculture, Food and Rural Affairs

Quack grass

Scientific Name: Agropyron repens (L.) Beauv.

Other Names: AGGRE, chiendent, Couch grass, Quitch grass, Scutch grass, Twitch, Twitch grass, chiendent rampant, agropyron rampant, Elytrigia repens (L.) Nevski, Elymus repens (L.) Gould

Family: Grass Family (Gramineae)

General Description: Perennial, spreading by seed and by light-coloured underground stems (rhizomes).

Habitat: Quack grass occurs in cultivated fields, pastureland, waste places, rights-of-way, lawns and gardens in almost any soil texture throughout Ontario. This is the most troublesome perennial weedy grass in Ontario and throughout Canada.


  • First shoot leaves are sometimes hairy, after that they are hairless
  • New leaves appear rolled up on emergence


  • Rhizomes have nodes or joints and internodes, are hard, white, very
  • Sharp-pointed tips
  • Roots and branches are produced from the nodes- some turnup wards, others grow horizontally and expand the patch
  • Each internode is partly covered by a short, light brown, dry, scale sheath


  • Erect
  • 30- 120 cm (1- 4 ft) tall
  • Either not flowering during the whole growing season or producing a slender, unbranched inflorescence called a spike
  • Stem nodes (joints) distinct and often purplish


  • Flat
  • Nearly smooth
  • Lower leaf sheaths hairy, upper ones often smooth
  • Sheaths split with margins overlapping
  • Auricles present and clasping the stem like little hooks


  • Spike (seed head) with 1 (rarely 2) unstalked spikelet at each node or joint
  • Spikelets alternating from one side of the rachis (central stalk of the spike) to the other, and with their flat or broad side towards the rachis
  • Each spikelet made up of 3 to 7 florets ("seeds") side by side between 2 outer glumes (empty chaff), and either with short awns (bristles) or awnless
  • Flowers from June to September

Often Confused With
Smooth Brome (Quackgrass is distinguished from smooth brome by its slender, unbranched seedhead (spike), the presence of auricles, its split sheath, and its sharp-pointed light-coloured rhizomes with short scaly sheaths)

Quack grass auricle Quack grass rhizomes Quack grass seed head Quack grass ligule
Click to enlarge.