Blue grama

Blue grama is one of the shorter prairie grasses.

Blue grama is smaller than the closely related side oats grama, growing only 8 to 15 inches tall.  It was a common grass in the shortgrass prairie. 

This plant has some cultivated varieties. Go to list of cultivars.

Botanical name:

Bouteloua gracilus

All Common Names:

Blue grama, mosquito grass

Family (English):

Grass

Family (Botanic):

Poaceae

Tree or Plant Type:

  • Grass,
  • Perennial

Native Locale:

  • Illinois,
  • North America

Landscape Uses:

  • Container,
  • Foundation,
  • Massing,
  • Mixed border,
  • Patio/sidewalk

Size Range:

  • Medium plant (12-24 inches),
  • Small plant (6-12 inches)

Light Exposure:

  • Full sun (6 hrs direct light daily)

Hardiness Zones:

  • Zone 3,
  • Zone 4,
  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7,
  • Zone 8,
  • Zone 9,
  • Zone 10

Soil Preference:

  • Alkaline soil,
  • Moist, well-drained soil

Season of Interest:

  • Early winter,
  • Mid winter,
  • Mid summer,
  • Late summer,
  • Early fall,
  • Mid fall,
  • Late fall

Flower Color & Fragrance:

  • Purple

Shape or Form:

  • Upright

More Information:

Size and Form

This species is a small grass growing 8 to 10 inches tall ( up to 15 inches when in flower).  The habit is upright.

Plant Care

Blue grama tolerates heat and drought well.
In the Southwestern United States it is used a mowed turfgrass.  It does not do well as a lawn in the Midwest due to the climate being too wet.

While it is considered a clumping grass, it does actually spread very slowly by rhizomes.  It also spreads by seed.
This is a warm season grass, so its most active growth occurs in summer.  It will remain standing in winter and can act as winter interest.
Since this grass remains attractive through winter, it should not be cut back until early spring, before new growth begins.  At that time, it can be cut down to the ground.

Disease, pests, and problems

No serious problems.

Native geographic location and habitat

Native to most of North America, including a few counties in Illinois.

Leaf description

The leaves are up to 10 inches long, but narrow and grown mostly from the base of the plant.  In summer, the leaves are gray-green.  In autumn, the leaves take on purplish tones.  During winter, the leaves are tan or straw colored.

Flower description

Flowering occurs in late summer (usually July to September).  The tiny, purplish flowers are held in comb-like structures resembling mosquito larvae (the reason for one of the common names), held at right angles to the stalk.  The flowers are wind pollinated.

Fruit description

The small fruit (caryopsis or grains) form within the comb-like structure that held the flowers.  The comb-like structures start out silvery-white, then turn purple and then straw colored as they mature.

Cultivars and their differences 

Blond Ambition (Boutleloua gracilis 'Blond Ambition'): This cultivar has larger flowers than the species and and they and chartreuse colored instead of purplish.  The fruit mature to a blonde color.

Location of Bouteloua gracilus (Blue grama) at the Arboretum

We do not seem to have this in our living collection.