Squirreltail (Elymoides)

The Squirreltail (Elymoides) is generally described as a perennial graminoid. This is native to the U.S. (United States) has its most active growth period in the spring . The greatest bloom is usually observed in the mid spring, with fruit and seed production starting in the spring and continuing until summer. Leaves are not retained year to year. The Squirreltail (Elymoides) has a long life span relative to most other plant species and a moderate growth rate. At maturity, the typical Squirreltail (Elymoides) will reach up to 1.5 foot high, with a maximum height at 20 years of 0 inches.

The Squirreltail (Elymoides) generally appears in field collections and doesn't tend to be commercially available. It can be propagated by seed. It has a slow ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -43°F. has high tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Reclamation/re-vegetation: Squirreltail displays many qualities which make it a good choice for what has been described as “assisted succession.” It is a short-lived perennial grass which can act as an early-seral species by competing with and replacing annual weedy species following fire. It is thought that after squirreltail establishes, annual weedy species should decrease in frequency and longer-lived, native perennials may be more successfully reseeded and established.

Its ability to germinate in the late fall and very early spring at a wide range of temperatures add to its capability to compete with cheatgrass (Bromus tectorum L.). Studies also indicate that squirreltail is capable of establishing in medusahead wildrye (Taeniatherum caput-medusae (L.) Nevski) infested sites. This makes squirreltail one of the more competitive native grasses available for reseeding disturbed rangelands. It is also a self-fertilizing species which allows it to produce seed despite sparse stands following seeding.

Squirreltail is considered to be one of the most fire resistant native bunchgrasses. Older plants contain relatively low amounts of dead material when compared with other native bunchgrasses. This allows for hot, but quick burns which do not penetrate and damage the crown. However, during dry years plants can be damaged by severe burns. As an early-seral species, new plants often increase for two to three years following burns.

Erosion control: When in large, dense stands, squirreltail is very effective at controlling wind and water erosion, due to its persistent ground cover.

Forage/wildlife: Squirreltail is considered to be fair to desirable forage for cattle, horses and sheep in spring before seed head development and late summer to fall after seed shatter. The long, sharp awns of the florets and glumes can be injurious to grazing animals during mid to late spring into summer. Leaves green up in very early spring and are palatable through the fall, especially following rain. The tendency for some leaves to remain green through the winter makes squirreltail an important, though not especially nutritious, winter forage species. Table 1 shows crude protein levels for the spring, summer and winter.

Table 1. Crude protein levels by season % Crude protein Spring 18.5 Summer 8.0 Winter 4.3 (Adapted from Monsen et al, 2004)

General Characteristics

General: Squirreltail is a cool-season C-3 bunchgrass native to the western United States. Foliage can be glabrous but is more often white hairy throughout. Plants are short, 10 to 45 cm (4 to 25 inches) tall, with culms erect to spreading. Leaf blades are flat to involute, 1 to 6 mm (0.04 to 0.24 inches) wide. The inflorescence is a spike from 2 to 17 cm (0.8 to 6.7 inches) long, not counting the awns. Internodes of the inflorescence are from 2 to 10 mm (0.08 to 0.40 inches) long with the rachis disarticulating regularly. At maturity the spike can be over 12 cm (4.7 inches) wide due to the widely spreading awns. Awns are scabrous and may grow from 2 to as much as 10 cm (0.8 to 3.9 inches) long, these often becoming purple with maturity.

Squirreltail is a self-pollinating allotetraploid and is known to hybridize with other species of Elymus as well as with members of Hordeum (barley) and Pseudoroegneria (bluebunch wheatgrass). Plants flower from late May to August.

Required Growing Conditions

Squirreltail (in the broad sense) can be found throughout western North America from Canada to Mexico. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Habitat: Bottlebrush and big squirreltail grow in a wide range of habitats, from shadscale communities to alpine tundra. Elymus elymoides ssp. elymoides is common at low to middle elevations in the western states. Subspecies californicus is native to mid-elevations up to alpine areas of Canada, California, Nevada and Utah. Subspecies brevifolius is found in a wide variety of habitats including desert and mountain plant communities, while subspecies hordeoides is restricted to the low lands of the Great Basin. Elymus multisetus occupies a similar range to ssp. elymoides, but is typically found in somewhat wetter, more mesic sites often in and near mountain foothills.

Adaptation In general, squirreltail is adapted to a wide range of ecological and topographical conditions. Plants can be found from 600 to 3,500 meters (2,000 to 11,500 feet) elevation in desert shrub to alpine plant communities. The different species-subspecies are adapted to sites receiving as little as 8 inches mean annual precipitation on upland sites or 5 to 9 inches in low lying areas that receive additional moisture. Big squirreltail is normally found in sites with 10 inches or more mean annual precipitation. Squirreltail grows well in medium to fine-textured soils, but also commonly occupies coarse-textured to gravelly soils. It tolerates low to moderately saline to alkaline run-in or overflow sites with electrical conductivity (EC) generally less than 10.

Cultivation and Care

For best results, seed should be planted to a depth of ¼ to ½ inches into a firm weed-free seedbed. For pure stands the recommended drill seeding rate is 7 lb pure live seed (PLS) per acre. Seed can be planted in early spring, but late dormant fall seeding is recommended for best annual weed suppression.

Squirreltail does not establish well into existing perennial shrub communities without mechanical treatment to reduce shrub density. Studies show four times the establishment success rate of squirreltail when planted after thinning big sagebrush (Artemisia tridentata Nuttall) as opposed to an untreated site. Similarly, it has been difficult to establish squirreltail in stands of crested wheatgrass (Agropyron cristatum [L.] Gaertner). It is recommended that crested wheatgrass and other perennial species competition be eliminated or severely reduced prior to seeding native seed mixtures that include squirreltail.

General Upkeep and Control

Seeds germinate in the fall or spring. Plants green up early and remain green through the fall and into winter. Stands should be protected from heavy grazing especially during flowering to ensure sufficient seed production to maintain the stand. New plantings should also be protected from grazing for at least two growing seasons. A direct seeded squirreltail stand in a big sagebrush/bluebunch wheatgrass community in south-central Idaho has survived for 30 years with recruitment from natural reseeding.

Wildland seed collection occurs from July to September before disarticulation of the spike. Best germination rates come from seed collected in stands with fifty percent of the seed heads having divergent awns and the other half having straight awns of a reddish color. This occurs approximately one week prior to disarticulation. One hour collecting for a single person averages a yield of about 1.6 oz of clean seed. Seed yields can vary widely depending on stand density and age.

Pests and Potential Problems Plants are known to be susceptible to rust.

Seed Production Plant seed in a 36-inch between-row spacing at a rate of 2.4 lbs PLS/acre for 30 PLS per foot of row. Fields should be weed free and have good field moisture to a depth of at least four inches. Soil should be kept moist throughout the germination phase (about 14-28 days). Fifty percent of germination should occur within 15 to 30 days after planting. Broadleaf weeds can be controlled with low rates of bromoxynil at the three to five leaf stage. Always apply herbicides according to label directions. No fertilizer should be applied during the first year to discourage annual weed competition.

Soil moisture should be carefully maintained during early green-up, boot stage, milk stage of seed development and after harvest. No irrigation should be applied during flowering to encourage seed set. Fertilize established fields at 100 lb nitrogen and 40 lb phosphorus per acre in mid-September. Soil testing is recommended to ensure proper rates of fertilization.

Broadleaf weeds can be controlled with herbicides. Application should occur prior to boot stage. Between-row cultivation can be used to control other weeds for the life of the stand.

Seed is ready to harvest in about mid-July of the second growing season (see “management” section for timing). Harvest by windrowing followed by combining. Some report difficulty with mechanical harvesting due to the ready disarticulation of the rachis of mature seed heads. Swathing prior to maturity and curing in windrows will help reduce this problem. Flail-vac and seed stripping harvesting equipment have also been used with varying degrees of success.

Because of the large amount of inert material produced from awns and glumes, this is a very time-consuming species to clean. Thresh seed through a hammer mill to remove awns. Follow with a clipper or other separator. Purity should exceed 90% with greater than 85% viability. Big squirreltail, in particular, has proven difficult to debeard without seed damage. Some seed companies have modified equipment that has resulted in improved seed viability.

Seed yields under irrigated conditions average approximately 200 lb/acre with 190,000 seeds/lb. Harvested seed should be dried to 12% or less moisture before storing. Storing seed in a cool dry environment will retain viability for several years.

Plant Basics
Growth Rate Moderate
General Type Graminoid
Growth Period Spring
Growth Duration Perennial
Lifespan Long
Plant Nativity Native to U.S.
Commercial Availability Field Collections Only
Physical Characteristics
Bloom Period Mid Spring
Displays Fall Colors No
Shape/Growth Form Bunch
Drought Tolerance High
Shade Tolerance Intolerant
Height When Mature 1.5
Vegetative Spread None
Flower Color Yellow
Flower Conspicuousness No
Fruit/Seed Abundance Medium
Fruit/Seed Seasonality Spring Summer
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Seed
Moisture Requirements Low
Cold Stratification Required No
Minimum Temperature -43
Soil Depth for Roots 12
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Regrowth Rate Moderate
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 6–8.4 pH
Precipitation Range 5–5 inches/yr
Planting Density 0–0 indiv./acre
Soil Textures Fine, Medium
Soil Depth for Roots 12
Minimum Frost-Free Days 90 day(s)
Salinity Tolerance Low
CaCO3 Tolerance High
Sustainability & Use
Leaf Retention No
Palatability Medium
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database, plants.usda.gov.
National Plant Data Center, Baton Rouge, LA 70874-4490 USA