Bermudagrass (Cynoden spp.) and quackgrass (Elymus repens or Elytrigia repens) are both perennial grass species that have a spreading habit and can be unwanted or invasive. Knowing which grass you are dealing with can help you plan how to address it. In some cases, the climate where the grass is growing is a sufficient clue. While quackgrass grows across an area that covers at least U.S. Department of Agriculture plant hardiness zones 3 to 11, Bermudagrass is found in USDA zones 7 to 10, although a few hardy strains survive winters in USDA zones 5 and 6.
Bermudagrass is a warm-season grass that turns a straw-brown color following frost. It can grow well in temperatures above 100 degrees Fahrenheit. Quackgrass is a cool-season grass and readily crowds out warm-season grasses and other vegetation that does not break dormancy or sprout until later in the year than the quackgrass, hogging moisture and nutrients. So, quackgrass will generally green up earlier in the year than Bermudagrass. Both of these grasses spread using rhizomes, horizontal underground stems, but Bermudagrass also produces stolons, horizontal stems that are located above ground.
It may be difficult to gauge the size of a grass plant if you continuously mow or trim it, but letting these grasses reach their mature height is very telling. Quackgrass is erect, can grow in clumps and reaches a mature height of almost 4 feet. Bermudagrass, alternatively, has stems that typically only grow 4 to 6 inches tall, although stems can grow up to 12 to 18 inches tall when growing conditions are favorable.
Quackgrass leaves are 1 1/2 to 12 inches long and usually about 1/8 to 1/4 inch wide with a rough or slightly hairy upper surface and a smooth lower surface. The quackgrass leaf sheath, the part of the leaf that wraps around the stem, is round and short and has overlapping margins. The projection inside and on top of the sheath, the ligule, is very short and membranous. Bermudagrass leaves measure 2 to 7 inches long and are less than 1/5 inch wide. The grass blades are smooth or sparsely hairy. Leaf margins are slightly rough and sheaths are distinctly flattened. The Bermudagrass ligule is a circle of white hairs.
Flowers and Seeds
Quackgrass flowers from May through September, producing a flower head that is a spike and measures about 2 to 8 inches long. Flattened, stalk-less spikelets where seeds later develop grow out of the spike in an alternating pattern. The Bermudagrass inflorescence consists of three to seven spikes that each measure 1 to 3 inches long and radiate out from a single point. Each spike contains spikelets arranged in two rows.
- United States Department of Agriculture Natural Resources Conoservation Service: Bermudagrass
- Virginia Tech Weed Identification Guide: Bermudagrass or Wire Grass
- Tonto National Forest: Invasive Weeds - Quackgrass
- Ohio Perennial and Biennial Weed Guide: Quackgrass
- United States Department of Agriculture Natural Resources Conservation Service: Plants Profile for Elymus Repens
- University of California Statewide Integrated Pest Management Program: Quackgrass
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