Cheatgrass or Drooping Brome
Bromus tectorum · Cool-season, Annual, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Bromeae
Grass Category
Invasive/Weed Grass, Range/Pasture (low quality)
Variety / Cultivar
None (Wild type species)
Hardiness Zones
USDA Zones 3-11; extremely cold tolerant as a seedling; escapes summer heat by dying back to seed mid-summer.
About This Grass
A winter annual grass that grows 2-24 inches tall. It is characterized by its light green, hairy foliage and a distinct drooping or nodding panicle of spikelets. It turns purple-red as it matures and eventually transitions to a distinctive tan/golden brown when dry and straw-like.
Blade Characteristics
Fine to medium width (2-5mm); flat blades that are softly pubescent (hairy) on both sides; pointed tips; light green to lime green color; rolled vernation; membranous, fringed ligule (1-3mm); auricles are absent.
Root System
Shallow, fibrous root system; quick establishment in disturbed soils; does not form a dense sod or thatch, but creates high levels of dry fine-fuel litter.
Growing Information
Origin Region
Native to Europe, southwestern Asia, and northern Africa; highly invasive in Western North America (Intermountain West)
Growth Habit
Bunch-type (clump-forming); strictly annual, reproducing solely by seed; fast-growing and aggressive
Sunlight & Water Needs
Full sun to partial shade; very low water needs; high drought tolerance due to its annual lifecycle (it completes its life before summer heat); thrives in well-drained, nutrient-poor soils.
Mowing & Maintenance
Not typically mown as a desired grass; maintenance involves prevention of seed set via early mowing (before purple stage) or chemical control. Low maintenance as a weed, but high effort required for eradication.
Special Characteristics
Highly flammable when dry; seeds contain stiff awns (1-2cm) that can injure livestock and pets; high seed production (up to 300 seeds per plant); excellent at outcompeting native perennials for early spring moisture.
Ecological Information
Highly invasive in the US; significant threat to sagebrush ecosystems; alters fire regimes by increasing frequency and intensity of wildfires; provides minimal forage value once mature/dry.