Big Bluegrass

General Description

Big bluegrass is a native, cool season, long-lived, perennial bunchgrass that matures early in the growing season. It is part of what is referred to as the Sandberg bluegrass complex, which includes 8 species, including big bluegrass, Canby bluegrass, slender bluegrass, Alkali bluegrass, Nevada bluegrass, Sandberg bluegrass, and pine bluegrass. The differentiating characteristics within this complex of species often vary with environmental factors, making distinguishing amongst them very difficult. Big bluegrass is the most robust of this collection and stands out for its large forage production and early spring growth. It has been used successfully for reseeding burned forest areas and is used by upland game birds for nesting.

Type

Native grass.

Origin

Big bluegrass is native to North America.

Longevity

The longevity of big bluegrass stands can exceed 30 years. This is partially due to seed shatter and the prolific “reseeding” of this plant species.

Use

Reclamation, grazing, hay. Upland game birds eat the seeds and use big bluegrass for nesting areas. It is also an important species for reseeding rangelands, stabilizing critical areas, reclaiming mine soils, and revegetating disturbed areas in aspen and conifer forests. Collections in Alaska have been used for erosion control, reclamation, and native plant community restoration.

Optimal Time of Use

Big bluegrass begins growing very early in the spring and up to 4 weeks earlier than crested wheatgrass. However, grazing on newly establishing stands should be deferred for 1 to 3 years.

Recovery After Use

Big bluegrass is considered an increaser species after grazing. It resists trampling very well as it goes dormant during summer and fall.

Palatability/Nutritional Value

Palatable for livestock in spring and fall, for deer in the spring, and for elk in all seasons. As curing progresses over the summer, livestock preference for big bluegrass decreases.

Annual Precipitation min/max (mm)

255mm / 610mm

Drought Tolerance

Does not tolerate drought as well as other cool season grasses.

Flooding Tolerance

Although it will grow in moist conditions, it will not tolerate early spring flooding, poor drainage, or high water tables.

Winter Hardiness

Big bluegrass is rated with excellent cold tolerance, but this rating is from the lower Columbia Basin in the U.S. Pacific Northwest where winters are milder than in many parts of British Columbia.

Soil Texture Preference

Thrives on a variety of soil textures from moderately coarse sands to dense clays.

Erosion Control

Very little to moderate erosion tendency – Southern Interior.

Salinity Tolerance

Low tolerance.

Acidity Tolerance

Low tolerance. Can tolerate pH down to 6.0.

Alkalinity Tolerance

Low tolerance (up to pH 8.0). Not suited for seeding on alkali flats.

Seeds per kg

2,000,000 seeds/kg (926,000 seeds/lb)

Suggested Mixtures

Can be mixed with native fescues, wheatgrasses, and wildryes.

Ease of Establishment

Some varieties of big bluegrass shatter easily and grow from scattered seed, thus stands can improve and fill in over time. Cheatgrass can be a problem for establishment. Weeds such as Russian thistle and prickly lettuce are less problematic.

Competitiveness

Once established, big bluegrass, especially the Sherman variety, competes well with cheatgrass.

Management Considerations

When seeded with other native plants, big bluegrass is often a minor component of the mix. Management of the stand should consider major species in the mix and overall seeding objectives.