Quackgrass
Elymus repens (formerly Agropyron repens) · Cool-season (C3), Perennial
Grass Family
Poaceae, Pooideae, Tribe: Triticeae
Grass Category
Invasive/Weed Grass, Agricultural Weed
Variety / Cultivar
Not applicable (Wild Type / Common weed form)
Hardiness Zones
USDA Zones 3-9. Highly cold-tolerant; goes dormant and turns straw-colored in winter, greening up very early in spring.
About This Grass
A vigorous perennial grass that appears as a coarse, clumping weed in manicured lawns. It features upright stems that can reach 3 feet if unmowed, a dull blue-green to dark green color, and a distinctive wheat-like seed head (spike) 2-8 inches long.
Blade Characteristics
Coarse blades (4-10mm wide), flat, with a sharp-pointed tip. The upper surface is often slightly pilose (hairy) and rough to the touch. It has distinctive clasping auricles (long, slender claws) at the collar, a short membranous ligule, and vernation is rolled.
Root System
Moderately deep, extensively creeping rhizomatous system. The rhizomes are yellowish-white, thick, and have sharp tips capable of penetrating potato tubers or heavy soil. Rapid establishment; high thatch tendency.
Growing Information
Origin Region
Native to Europe, North Africa, and Western Asia; naturalized throughout North America and other temperate regions.
Growth Habit
Rhizomatous (Extremely aggressive spreading via long, sharp, white underground rhizomes); mat-forming.
Sunlight & Water Needs
Full Sun to Partial Shade; prefers moist, fertile soils but is highly drought-tolerant once established. High adaptability to various pH levels.
Mowing & Maintenance
Maintenance level is low from a survival standpoint but high for control. Mowing to 2-3 inches does not eliminate it due to its low-growing rhizomes. Control usually requires non-selective herbicides or intensive physical removal of all rhizome fragments.
Special Characteristics
High wear tolerance; allelopathic properties (releases chemicals that inhibit the growth of surrounding plants); extremely difficult to eradicate from turf due to rhizome fragments regrowing.
Ecological Information
Introduced/Invasive status in North America. Provides minimal wildlife value (seeds eaten by some birds), but primarily considered a noxious weed that out-competes native species and reduces agricultural yields.