Annual Bluegrass
Poa annua · Cool-season annual (rarely perennial), C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Invasive/Weed Grass in lawns and sports turf
Variety / Cultivar
Common Poa annua (wild type)
Hardiness Zones
USDA Zones 3-11; survives cold winters but senesces (turns brown and dies) when soil temperatures exceed 80-85°F.
About This Grass
A low-growing, bright yellowish-green tufted grass that stands out against the darker, coarser Bermuda grass. It forms dense, light-colored clumps and is known for producing prolific white seed heads even at very low mowing heights.
Blade Characteristics
Fine to medium width (2-3mm), soft texture, light green color; folded vernation; distinct boat-shaped leaf tips; long, white, membranous ligule; no auricles; blades usually have crinkled or wavy sections across the leaf surface.
Root System
Very shallow fibrous root system; low thatch tendency; easy to pull up; poor drought tolerance due to shallow roots; dies quickly in high heat.
Growing Information
Origin Region
Originating in Europe and Eurasia; now established globally in temperate climates
Growth Habit
Bunch-type/Clumping; occasionally develops short stolons; forms dense tufted mats
Sunlight & Water Needs
Prefers partial to full sun but tolerates shade better than Bermuda; requires frequent moisture/wet conditions; thrives in over-watered or compacted soils.
Mowing & Maintenance
Maintenance involves removal rather than cultivation; mowed height typically 0.5-2.0 inches; high seed production despite frequent mowing; difficult to control without pre-emergent herbicides.
Special Characteristics
Extremely prolific seeder; high shade tolerance compared to Bermuda grass; poor heat and drought tolerance; highly opportunistic in compacted, damp soil patches.
Ecological Information
Introduced species; generally considered a weed in managed turf; provides food for some small birds but tends to displace desired turfgrasses and creates unsightly dead patches in summer.
Notes
Patch of grass surrounded by Bermuda