Plant of the Month (November) : Blue Grama/Eyelash grass – Bouteloua gracilis

 

Blue Grama (Bouteloua gracilis) looks attractive, even in fall and winter

We got 10 inches of snow in Mother Nature’s Montrose Garden the third week in October.  While a little snow and cold is not uncommon, this was a lot of snow for this early.  It got us thinking about plants that add winter interest to the garden – even when covered in snow.  And that brings us to our plant of the month: Blue Grama, Bouteloua gracilis. The scientific name is pronounced boo-te-LOO-uh  GRASS-il-is.  

As sees in the photograph, Blue Grama is in the Grass Family (Poaceae).  The Boutelouas or Grama grasses are native to the Americas, with the greatest diversity in the Southwestern U.S. and Mesoamerica. While more commonly named  Bouteloua gracilis, Blue grama is sometimes classified as Chondrosum gracile. [1] Chondrosum is closely related to Bouteloua and some taxonomists group all or most under Bouteloua.  The genus is named after the Spanish horticulturalist  Claudio Bouteloua (1774-1842). [2]

There are about 50 species of Grama, with at least seven (Bouteloua curtipendula, B. dactyloides, B. eriopoda, B. gracilis, B. hirsuta and Chondrosum simplex/ Bouteloua simplex, C. barbatum/Bouteloua barbata) native to Colorado. [3] Bouteloua gracilis, which has the widest statewide distribution, is the Colorado State Grass.

Blue Grama (Bouteloua gracilis): San Miguel county, CO

In fact, Blue grama has the widest distribution of all the grama grasses. Its range extends as far north as Alberta, Canada and as far south as Mexico. It is present in most of the Midwestern United States, extending east to Missouri and Texas, and as far west as Southern California. [4] In Colorado, it is common on both the Western Slope and Front Range.  And it occurs in a number of plant communities throughout its range, including grasslands, shrublands, woodlands and forests.

Blue grama is a warm season perennial grass, which means that its optimum growth is at temperatures between 80 and 95°F (27 to 35°C).  That being said, growth of Blue grama slows during very hot, dry conditions. In Mother Nature’s Montrose Garden, it grows most actively in early summer and again in fall. Plants are dormant in winter, with leaves turning purple, then tan, with autumn frosts.

Blue Grama (Bouteloua gracilis): plant

Bouteloua gracilis grows 12-18 inches tall and wide, making it one of the shorter native grasses.  It is finely textured, with blades at most 6 inches long and less than ½ inch wide (< 15 cm long, < 2 mm wide) and drooping. Leaf color is medium green to blue-green.  The overall impression is of a compact, neat-looking bunch grass.  That is probably one reason that it has been embraced by the horticultural community.

Blue Grama (Bouteloua gracilis): reprduction

Blue grama spreads slowly by seed and sometimes by tillering (vegetative reproduction).  There is some debate as to why some Bouteloua gracilis spread vegetatively, while others appear to not do so.  Part may be due to genetic variability. But another likely factor is differences in growing conditions.  Having observed this plant in both the wild and the garden, we suspect that soil moisture plays a role.  The species appears to spread very slowly in dry, mid-elevation sites in Western Colorado.  In the garden, Blue grama has spread more quickly (see above photo).

Blue Grama (Bouteloua gracilis): in flower

Like all grasses, Bouteloua gracilis is wind pollinated and expends little energy on colorful flowers. That being said, Blue grama is one of the prettier grasses when in flower. The flowers grow on a stalk that extends above the leaves, to about 20 inches tall. The flowers themselves – and then the seeds – are suspended horizontally, somewhat like a miniature brush (below). The fresh flowers are reddish-purple; they mature to light tan color.  Seeds are dispersed by wind, water, animals and by ‘hitch hiking’ on an animal’s fur.

Blue Grama (Bouteloua gracilis): showy flowers

Blue Grama (Bouteloua gracilis): seeds

As expected from its wide range, Bouteloua gracilis succeeds in a range of climates and soil conditions. It grows in USDA Zones 3-10, making it a good choice for both colder and warmer parts of the West.  It needs a well-drained soil, but tolerates soils on both the sandy or clay ends of the spectrum – even rocky soils. It tolerates soils with pH from 6.0 to 8.0 – possibly even higher.  It does well in full sun to part-shade, and needs only an occasional light dose of fertilizer – if that. 

Bouteloua gracilis is well suited for the dry West. It has a complex root system that includes shallow, fibrous roots and deep roots (to about 6 ½ ft).  This combination of shallow and deep roots is common in native plants subjected to extremes of soil moisture. The shallow roots allow plants to extract seasonal soil moisture, while the deep roots make the plants more drought tolerant.

Blue Grama (Bouteloua gracilis): in Mother Nature's
 Montrose Garden

While Blue grama is drought tolerant, it really looks best with occasional water during prolonged periods of hot, dry weather.  In many Western gardens, plants will thrive on occasional deep summer watering – perhaps every other week or monthly, depending on the soil type.  Since Blue grama has only moderate salt tolerance it is not a good choice for gardens using recycled water, which tends to have high salt concentrations.   It also does poorly in areas with a high water table.

Blue Grama (Bouteloua gracilis): seedlings

Blue grama is often sold as a water-wise lawn substitute, often in combination with the native Buffalo grass, Bouteloua dactyloides.  For this use, Blue grama is either seeded during warm weather or planted as plugs.  Getting this grass established from seed can be a challenge, particularly in areas with dry, windy Springs. Like all grasses, keeping the ground and seedlings/young plants moist is a must during establishment. For more on planting native grass lawns, see reference 5.

Blue Grama (Bouteloua gracilis): ground cover around trees

Blue grama lawns can be mowed occasionally once well-established.  But the grass is so attractive that many gardeners choose not to.  This species makes a particularly showy addition to prairie or meadow plantings, looking best when planted in masses or swathes.  It does well as a ground-cover between trees and native shrubs (above).  Its small size makes it a good choice for rock gardens and other small-scale plantings. It can even be grown as an accent plant in containers. We also like it as an edging plant around seating areas (below).

Blue Grama (Bouteloua gracilis): nice around seating area

Several attractive and useful cultivars are available as either seed or plants.  ‘Alma’ is a robust, upright plant with good seedling vigor. ‘Hachita’ is a vigorous New Mexico variety chosen for its ability to fill in quickly and make a dense turf. [6]   These two are available as seed from your local ag extension office or commercial growers.   Native plant nurseries may also have ‘Hachita’ as plants or plugs.

Bouteloua gracilis ‘Lovington’, also from New Mexico, is uniform in its growth, making it a good choice for lawns. It is available from commercial seed companies. ‘Blond Ambition’, available as plants from a growing number of sources, is a larger, more showy cultivar with light green flowers that turn to tan.  This is a lovely plant, even when the snows fly, and is gaining popularity as an ornamental ‘accent’ grass in Western gardens (below).

Blue Grama (Bouteloua gracilis) 'Blond Ambition'

We like Blue grama because it’s a grass native to Western Colorado. It just looks ‘right’ in local gardens and it has a long history of use as a forage crop and beyond. Seeds of the species were used as food where ever it grew. Native peoples have used the stems to make combs, brushes and brooms; some cultures have used the stems in basketry.  And the species is used ceremonially by the Navajo. [7]

So, if you are looking for a grass that’s attractive looking, tough as nails and has a nice history, Blue grama may be the right choice for your garden. Whether you use it as a native lawn, in a natural prairie or as a showy accent, you can’t go wrong with Bouteloua gracilis or its cultivars.

Blue Grama (Bouteloua gracilis): notrhering prettier than sunlight through grasses

 

For a gardening information sheet see: https://www.slideshare.net/cvadheim/gardening-sheet-bouteloua-gracilis

For more pictures of this plant see: https://www.slideshare.net/cvadheim/bouteloua-gracilis-web-show-239151795

For plant information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html

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1.   Weber WA and Wittmann, RC. Colorado Flora – Western Slope: A Field Guide to the Vascular Plants (4^th ed). Boulder CO, University Press of Colorado, 2012.

2.   http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=BOUGRA

3.   Ackerfield, J: Flora of Colorado. Ft. Worth, TX, BRIT Press, 2015.

4.   Anderson, Michelle D. 2003. Bouteloua gracilis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).  http://www.fs.fed.us/database/feis/plants/graminoid/bougra/all.html

5.   https://www.highcountrygardens.com/gardening/planting-blue-grama-grass-seed-bouteloua-gracilis

6.   https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/nmpmcrb10444.pdf

7.   http://herb.umd.umich.edu/herb/search.pl?searchstring=Bouteloua+gracilis

 

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We welcome your comments (below).  You can also send your questions to: monaturesmontrosegarden@gmail.com