Quack grass, Agropyron repens
Weed Control Options 
Life Cycle
PerennialPropagation
Rhizomes and seed.Stems
Stems erect, 30-120 cm 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.Leaves
Leaves 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.Flowers and Fruit
"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."Roots and Underground Structures
Rhizomes have nodes or joints and internodes, and hard, white, very sharp-pointed tips. They produce roots and branches from the nodes. Some branches turn upwards to emerge as leafy stems. Others continue growing and branching horizontally and expand the patch. Each internode is partly covered by a short, light brown, dry, scaly sheath.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 considered the most troublesome perennial weedy grass in Ontario and throughout Canada.Competitiveness
Corn yield loss (%)*:4 % at 1 plant/m2
15 % at 5 plant/m2
Soybean yield loss (%)*:
4 % at 1 plant/m2
18 % at 5 plant/m2
*assumes that the weed has emerged with the crop and has been left uncontrolled all season.
Distinguishing Features
It is distinguished from Smooth brome by its slender, unbranched seed head (spike), the presence of auricles its split sheath, and its sharp-pointed light-coloured rhizomes with short scaly sheaths.Toxicity
Quackgrass is not known to be toxic.Human Health Issues
Quackgrass may cause allergies (hayfever).Forage Quality
No information exists at this time.Often Mistaken For
Wire-stemmed muhly.Power Ranking Corn
Power ranking↑ 10
Power Ranking Soybeans
Power ranking↑ 14
Biological Control
Currently none available for this weed. For the latest research on biological weed control: Click here
Biopesticide Control
Currently none available for this weed.Herbicide Resistance
No documented cases of herbicide resistance to date.For more information on weed resistance:
Click here
Media Items
Figure 1: Quackgrass: A. Non-flowering plant. B. Leaf-base. C. Spike. D. 1 Spikelet. Top
Figure 2: Ligule: membranous, but very short and hard to see. Top
Figure 3: Auricle: present at the base of the leaf blade. Top
Figure 4: Rhizomes: Sharp-pointed and far-reaching in the soil. Top
Figure 5: Seed head. Top