bulbous bluegrass
Poa bulbosa · Poaceae
bulbous bluegrass (Poa bulbosa) is a perennial 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 3 and warmer, down to about -33°F.
At a glance
| Type | graminoid USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | introduced USDA |
| Mature height | 1.5 ft USDA |
| Light | part-shade USDA |
| Water need | medium USDA |
| Growth rate | moderate USDA |
| Soil pH | 5–7.2 USDA |
| Bloom | May–June USDA |
| Flower color | Yellow USDA |
| Hardiness zones | 3 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 medium. It is recorded on soils from pH 5 to 7.2 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 1.5 ft, making it about knee height. It grows at a moderate rate.
Bloom period
USDA records a bloom period of May through June. 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 and fall. USDA rates its lifespan as long.
What the site needs to provide
USDA records it across sites receiving 12 to 40 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 100 frost-free days to finish its season. It roots to at least 8 inches. Fertility requirement: medium.
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 moderate 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 high. 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
- annual bluegrass Poa annua
- arctic bluegrass Poa arctica
- autumn bluegrass Poa autumnalis
Similar role and hardiness
- velvet bentgrass Agrostis canina
- American water plantain Alisma subcordatum
- kinnikinnick Arctostaphylos uva-ursi
- golden sedge Carex aurea
- white marsh marigold Caltha leptosepala
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol POBU, 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, Lifecycle, lifespan, 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.
Find more plants for your zone with the Plant Finder.