annual bluegrass
Poa annua · Poaceae
annual bluegrass (Poa annua) is a annual grass or grass-like plant in the Poaceae family. It is introduced to North America rather than native. USDA records it as hardy in zone 11 and warmer, down to about 47°F.
⚠ Invasive or noxious status. USDA lists this plant with an invasive or noxious weed status somewhere in its range. Check your state's noxious weed list before planting it — in some states it is illegal to sell or plant.
Both flags are quoted from USDA PLANTS, not inferred.
At a glance
| Type | graminoid USDA |
|---|---|
| Lifecycle | annual USDA |
| Native status | introduced USDA |
| Mature height | 0.3 ft USDA |
| Light | part-shade USDA |
| Water need | medium USDA |
| Growth rate | rapid USDA |
| Soil pH | 4.8–8 USDA |
| Bloom | April–May USDA |
| Flower color | Yellow USDA |
| Hardiness zones | 11 and warmer USDA |
| Guild layer | ground-cover Derived |
| Nursery availability | Routinely Available USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It grows in partial shade. USDA rates it as having moderate water needs. Its drought tolerance is rated low. It is recorded on soils from pH 4.8 to 8 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 11.
Size and growth
At maturity it reaches about 0.3 ft, making it a low, mat-forming plant. It grows quickly.
Bloom period
USDA records a bloom period of April through May. Flowers are yellow.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, fine in texture. Its flowers are not conspicuous — a plant for form and foliage. Its active growth period is spring.
What the site needs to provide
USDA records it across sites receiving 24 to 60 inches of annual precipitation. It needs at least 60 frost-free days to finish its season. It roots to at least 3 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
Propagating it
Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a rapid rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated low. Its growth form is recorded as bunch.
Role in a guild
Ground cover. In a layered planting this is the lowest layer — it shades soil, holds moisture, and suppresses weeds. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Poa
- alpine bluegrass Poa alpina
- arctic bluegrass Poa arctica
- autumn bluegrass Poa autumnalis
- bulbous bluegrass Poa bulbosa
Similar role and hardiness
- ovate spikerush Eleocharis ovata
- tinker's penny Hypericum anagalloides
- toad rush Juncus bufonius
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol POAN, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Invasive status, Lifecycle, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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