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Summary
Duration	Perennial
Growth Habit	Graminoid
U.S. Nativity	Native to U.S.
Federal T/E Status
National Wetland Indicator	FACW
Morphology/Physiology
Active Growth Period	Spring, Summer, Fall
After Harvest Regrowth Rate	Slow
Bloat	None
C:N Ratio	Medium
Coppice Potential	No
Fall Conspicuous	No
Fire Resistant	No
Flower Color	Yellow
Flower Conspicuous	No
Foliage Color	Green
Foliage Porosity Summer	Porous
Foliage Porosity Winter	Porous
Foliage Texture	Medium
Fruit/Seed Color	Brown
Fruit/Seed Conspicuous	No
Growth Form	Rhizomatous
Growth Rate	Moderate
Height at 20 Years, Maximum (feet)
Height, Mature (feet)	3
Known Allelopath	No
Leaf Retention	No
Lifespan	Moderate
Low Growing Grass	Yes
Nitrogen Fixation
Resprout Ability	No
Shape and Orientation	Erect
Toxicity	None
Growth Requirements
Adapted to Coarse Textured Soils	Yes
Adapted to Fine Textured Soils	Yes
Adapted to Medium Textured Soils	Yes
Anaerobic Tolerance	Medium
CaCO3 Tolerance	Low
Cold Stratification Required	No
Drought Tolerance	Low
Fertility Requirement	Medium
Fire Tolerance	Medium
Frost Free Days, Minimum	90
Hedge Tolerance	None
Moisture Use	Medium
pH, Minimum	5.5
pH, Maximum	7.5
Planting Density per Acre, Minimum
Planting Density per Acre, Maximum
Precipitation, Minimum	6
Precipitation, Maximum	30
Root Depth, Minimum (inches)	10
Salinity Tolerance	Low
Shade Tolerance	Intolerant
Temperature, Minimum (°F)	-38
Reproduction
Bloom Period	Late Spring
Commercial Availability	Contracting Only
Fruit/Seed Abundance	Low
Fruit/Seed Period Begin	Summer
Fruit/Seed Period End	Summer
Fruit/Seed Persistence	No
Propagated by Bare Root	No
Propagated by Bulb	No
Propagated by Container	No
Propagated by Corm	No
Propagated by Cuttings	No
Propagated by Seed	Yes
Propagated by Sod	No
Propagated by Sprigs	No
Propagated by Tubers	No
Seed per Pound	5600000
Seed Spread Rate	Slow
Seedling Vigor	Low
Small Grain	No
Vegetative Spread Rate	Slow
Suitability/Use
Berry/Nut/Seed Product	No
Christmas Tree Product	No
Fodder Product	Yes
Fuelwood Product	None
Lumber Product	No
Naval Store Product	No
Nursery Stock Product	No
Palatable Browse Animal	Medium
Palatable Graze Animal	High
Palatable Human	No
Post Product	No
Protein Potential	Medium
Pulpwood Product	No
Veneer Product	No

 

Kingdom  Plantae -- Plants

Subkingdom  Tracheobionta -- Vascular plants

Superdivision  Spermatophyta -- Seed plants

Division  Magnoliophyta -- Flowering plants

Class  Liliopsida -- Monocotyledons

Subclass  Commelinidae

Order  Cyperales

Family  Poaceae -- Grass family

Genus  Agrostis L. -- bentgrass P

Species  Agrostis exarata Trin. -- spike bentgrass P

 

Alternate names: Other common names include spike redtop and western bentgrass. There are three recognized varieties:   A. exarata. var. exarata, A. exarata. var. pacifica Vasey, and A. exarata. var. monolepis (Torrey) Hitchc.  Spike bentgrass apparently hybridizes with A. scabra and A. stolonifera.

 

Uses: As a pioneer species, spike bentgrass has good potential for restoration of prairie wetlands, riparian areas, and other seasonally wet or intermittently flooded habitats.  It is also useful for revegetation of ditches, logged or burned over timberland, and other disturbances within brush and open woodland communities. 

 

Where locally abundant, this species is an important source of forage for livestock.  Foliage remains green and palatable throughout the summer.  Its palatability is rated good for cattle, horses, and elk, and fair to good for sheep and deer.  Spike bentgrass is also planted as a soil stabilizer in degraded areas and has been suggested for use in excluding reed canarygrass (Phalaris arundinacea).  Value for wildlife habitat is ranked high for numerous birds and mammals. Compared to many bentgrasses, spike bentgrass is considered by some as more compatible with other native grasses, forbs, and trees.

 

Description: Spike bentgrass is a medium textured, cool season, perennial bunchgrass with a dense, spike-like flower head (panicle).  The stems (culms) are slender and erect, usually 50 to 100 (150) cm tall.  The leaf blades are 2 to 20 mm wide, 5 to 20 cm long, and harsh to the touch.  This species contains considerable variability, from dwarf alpine forms to taller, more robust specimens along the seacoast.  Some texts indicate the occasional presence of short rhizomes and root development or growing points at lower nodes, but rhizomes appear to be lacking on plants in our area.  This species is found mostly in the western United States and Canada.  

 

Key to identification: Compared to most other bentgrasses, the panicle is particularly narrow and more spike-like.  It is 10 to 25 cm long.  The individual flower groups (spikelets) are very tiny and 1-flowered.  A botanical grass key may be required to accurately distinguish it from other bentgrasses.

 

Relative abundance in the wild: Spike bentgrass is relatively common is western Oregon, western Washington, and California. It can be locally abundant on moist sites throughout the western states. The species produces large quantities of tiny seeds with good retention that are easy to harvest or collect. It is usually not found in large pure stands, but occurs as scattered individuals or small colonies across a landscape.

 

Adaptation: Spike bentgrass has broad adaptation to a wide variety of habitats. Despite the tiny seed size, it is easy to establish and a high seed producer with good commercial potential. Spike bentgrass occurs in a wide variety of habitats including forest openings, grasslands, shrub lands, wet meadows, freshwater and high tidal marshes, as well as along streams, rocky beaches, and lake margins. It is most commonly found in moist open places, but occasionally grows in dry habitats such as semi-arid grasslands. Relatively shade intolerant, this species performs well on moderately acidic, mineral soils.  While most prevalent on disturbed sites such as ditches, harvested forestland, and roadsides, it may also be found in established meadow and riparian plant communities. Habitats range from sea level to alpine zones.  This species occurs mostly in the western United States and Canada.

 

Establishment: Some recommend a light debearding to remove the seed appendage (awn) in order to facilitate further seed cleaning and sowing with a drill. The seed has no dormancy and germinates readily. There are approximately 5,600,000 seeds/lb (+/- 20%). A seeding rate of 1 lb/acre of pure live seed would result in 125 live seeds per square foot.  Given the small seed size, the single species seeding rate is generally 1-3 lbs/acre, but some literature recommends a rate of 3-5 or up to 8 lbs/acre to attain a full stand.  The species establishes easily on moist, mineral soil in spring or fall.  However, the seed readily migrates in flood prone areas so a thin mulch layer coupled with a late summer or early fall plantings may be preferred.

 

Management: Information on this species is limited.  Moderate amounts of forage are produced and utilized by livestock, large game, and other wildlife well into summer. The ability of spike bentgrass to easily volunteer on moist, disturbed ground and readily produce seed makes it a candidate for moist soil management of wetland habitat for waterfowl, shorebirds, and other wildlife.

 

Limitations or environmental concerns:

Due to its abundant seed production and broad adaptability, it may be considered weedy in certain environments.  Please consult with your local NRCS Field Office, Cooperative Extension Service office, or state natural resource or agriculture department regarding its status and use.

 

Commercial availability of seed: Several seed sources are available for California and at least one for the Willamette Valley of Oregon.  Ecotypes may be harder to locate for other western states.

 

Prepared By:

Dale Darris and Amy Bartow, USDA NRCS Plant Materials Center, Corvallis, Oregon.

 

Species Coordinator:

Dale Darris, USDA NRCS Plant Materials Center, Corvallis, Oregon.

 

Edited: 16mar2006 jsp

 

For more information about this and other plants, please contact your local NRCS field office or Conservation District, and visit the PLANTS Web site<https://plants.usda.gov> or the Plant Materials Program Web site <https://Plant-Materials.nrcs.usda.gov>

 

 

 

Attribution:  U.S. Department of Agriculture