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Statewide IPM Program, University of California

Annual bluegrass
 (Poa annua )

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Life stages of Annual bluegrass seedling mature plant flower cluster collar region leaf tip

Annual bluegrass is a short, cool-season annual, biennial, or perennial grass. It is highly variable and is one of the most common weeds found throughout California, especially in coastal regions up to an elevation of 6600 feet (2000 m). Habitats include agricultural land and other disturbed areas. It can easily be distinguished from other grasses by its leaf tip, which is shaped like the bow of a boat.


Turf, gardens, landscape areas, fields, roadsides, vegetable crops, vineyards and orchards.


The membranous ligule is rounded with a slightly pointed, jagged tip.

Mature plant

Annual bluegrass growth is characterized by the spreading of dense, low clumps, 3 to 12 inches (8–30 cm) tall. Leaf blades are hairless, often yellowish green, and sometimes dark green. They are often crinkled at the midsection. It often roots at lower stem nodes and the root system is fibrous.


Visible mostly December through July, although in some sites it can be found nearly year round, the annual bluegrass flower head is triangular to egg shaped in outline. It branches more than once, is often pale, and at times, bright green to purplish. It has about three to eight flowers per spikelet.


Annual bluegrass reproduces by seed and can have many generations in a season.

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