Quackgrass

Quackgrass, courtesy of Dr. Lynn Clark and Anna Gardner, Iowa State University

Photo courtesy of Dr. Lynn Clark and Anna Gardner, Iowa State University

Common Name(s):

Quackgrass
Couchgrass
Witchgrass
Chiendent

Scientific Name:

Elymus repens (L.) Gould

Scientific Name Synonym(s):

Agropyron repens (L.) Beauv
Elytrigia repens (L.) Desv. ex B.D. Jackson
Triticum repens L.
Triticum vaillantianum Wulfen & Schreb.

Symbol:

ELRE4

Description:

Life Span: Perennial
Origin: Introduced
Season: Cool

 

Growth Characteristics: Quackgrass is an aggressive plant that reproduces by spreading from yellowish-white rhizomes and by seed. Rhizomes can grow 23 inches or more from the main shoot before sending out stems, and grow as deep as 8 inches.   Flowers from June to August. Native of Eurasia.

Seedhead: The seedhead is a spike, 1 ½ -7 ½ inches long, one spikelet per node. Spikelets are 3-5 flowered, 1/2-5/8 inch long; glumes are sharply tipped 1/4-5/8 inch long, first glume is slightly shorter than the second, glumes 3-7 nerved, ½ as long as spikelet. Spikelets are either unawned or bearing awns up to 1/8 inch long. Lemmas unawned or awn-tipped with awns up to 1/4 inch long; rachis of the spikelet hairless.

 

Leaves: Flat, smooth to finely hairy on upper surface, dark green, 3-12 inches long, 2 – 3 ½ inches wide, and often constricted near the leaf tips. Auricles clasping; ligules lacking; sheaths often hairy.

Stems: Erect stems, usually 1-3 feet tall, green to whitish-colored.
 

Ecological Adaptations:

Quackgrass is a rapidly invading grass on many agricultural lands, along ditches, and water courses; and is common in semi wet meadows. It is found at elevations from 4000 to 9000 feet on irrigated land or where annual precipitation averages 10-22 inches. 

 

Soils: Found on sandy to clay loam soils, and is not salt tolerant.

Associated Species: Kentucky bluegrass, smooth brome, orchardgrass, sagebrush, timothy.

Uses and Management:

Quackgrass provides fairly good spring forage, spreads rapidly, and quickly stabilizes moist, erodible soils. It is designated a noxious weed in the State of Utah, however, and is not recommended for seeding. Because of the ability of broken rhizomes segments to grow and produce new plants, it is extremely difficult to control mechanically. The scaly rootstocks contain sugar and triticin, a carbohydrate similar to insulin, valuable for treatment of kidney disorders. A poisonous fungus called ergot that replaces the seeds with black or purple club-shaped bodies is often found in both western wheatgrass and quackgrass. Livestock loss has resulted from ingestion of grasses with ergot from pasture, in hay, or in grain or grain screenings.

 

Although quackgrass is considered an undesirable weed species it is often crossed with other wheatgrasses (Agropryon spp.) to create hybrids for grazing. It can be controlled with chemicals such as glyphosate, dichlobenil, and fauzifop. Sometimes, however, chemicals are not effective. Mowing, burning, and chemical application combined may be the best way to eradicate quackgrass. Late spring fires generally decrease quackgrass cover, flowering and biomass, while early spring fires can increase them.

It provides cover for numerous small rodents, birds, and waterfowl.