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Tuber Oat Grass, Bulbous Oat Grass
Arrhenatherum elatius var. bulbosum

Family: Poaceae (poh-AY-see-ee) (Info)
Genus: Arrhenatherum (ah-ren-AH-ther-um) (Info)
Species: elatius var. bulbosum
Synonym:Arrhenatherum elatius subsp. bulbosum
Synonym:Arrhenatherum elatius var. tuberosum


Ornamental Grasses and Bamboo



6-12 in. (15-30 cm)

12-18 in. (30-45 cm)


9-12 in. (22-30 cm)


USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

Sun Exposure:

Full Sun

Sun to Partial Shade

Light Shade


Unknown - Tell us

Bloom Color:

White/Near White

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall


Grown for foliage


Other details:

Average Water Needs; Water regularly; do not overwater

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

Unknown - Tell us

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Allentown, Pennsylvania

Gardeners' Notes:


On Oct 5, 2010, wakingdream from Allentown, PA wrote:

In southeastern PA I found this plant on our property when we moved here in 1990. After 20 years it is still going, having been moved at least 3 times. It is a short, early, striking grass, soft to the touch and very attractive. It held on being stuck under a privet hedge that sucked all moisture away. It held on being placed in heavy shade, far away from the water source. It held on in a very moist spot near a birdbath (getting dumped and refilled for weeks) with afternoon shade but bright morning sun. It held on getting surrounded and obscured by taller self sowing cottage garden annuals. I have just recently moved it to a fresh spot where it can get more even light, less swampy conditions and have room to expand a bit. The interesting root system (bulbous nodules stacked together... read more