Warm Season Grasses

Warm Season Grasses sagem

The Species Production Guides for warm season grasses provide specific information about growing each of these species for seed production. 

Scroll the list (alphabetized by scientific name) or press ctrl-f (or command-f) to search for any name in this page. 

A printable file (pdf) is also provided on each species page for those needing a print version.

This section is a work in progress. We will continue to add new species guides as they are completed.


  • Sorghastrum nutans / Indiangrass

  • Spartina pectinata / prairie cordgrass 

  • Sporobolus compositus / composite dropseed

  • Sporobolus heterolepis / prairie dropseed 

big bluestem

big bluestem sagem

a field of big bluestem in flower, showing the typical 3-4 branched seedheads resembling turkeys' feet

 

Andropogon gerardii Vitman 

Alternate Common Names: turkey foot, turkeyfoot

Scientific Synonyms: Andropogon chrysocomus Nash, Andropogon furcatus Muhl. ex Willd., Andropogon provincialis Lam., Andropogon gerardii Vitman var. chrysocomus (Nash) Fernald

Family:grass family (Poaceae)

Functional Group: warm season grasses

Description 

Life cycle and growth form

Perennial with short rhizomes and fibrous roots that forms large clumps, a bunchgrass.

Height: 2-8 ft  

big bluestem (Andropogon gerardii) whole plant

Leaves and stem

big bluestem (Andropogon gerardii) leaf

Leaves flat with a prominent midrib, 1-2 ft long and 1/4 in wide, often with long, unkempt, white hairs near leaf base and on lower sheath, ligule is a short, fringed membrane; flowering culms (stems) are erect and hairless, solid, often reddish to bluish purple in color with a waxy bloom, usually with a few branches near the top.

Flower, fruit and seedhead

Fruit/seedhead: Seed heads (panicles) consist of 2-6 spikelike racemes 1.5-4 in long at the tips of branches, containing both seed-bearing and sterile flowers; seed heads appear bristly when mature and shatter from the tops especially on dry, windy days.

Pollination: wind

big bluestem (Andropogon gerardii) inflorescence

Seed

Seed characteristics 

Seeds per ounce: 10,000 (IA NRCS)

Seeds per pound: 160,000 (IA NRCS)

1000 seed weight: 2.14 g (Seed Information Database)

Description: Fertile spikelet with awn, 1-2 cm long (1/2-3/4 in), attached stalk(s) are covered with hairs prior to debearding. Caryopsis smooth, brown, 3-5 mm long.

Typical seed test 

PLS: 85%

Purity: 89%

Germination: 39%

Dormant: 56%

(averages obtained from 11 tests of purchased seed lots)

Habitat and range

‌Habitat: Mesic to wet-mesic soil; full sun; prairies, savannas, roadsides, fens, glades. Wetland Indicator Status is Facultative (FAC) for the Midwest. Moist, loamy, deep, well-drained soils are preferred for seed production.

Conservation status: Global- G5, secure; Wyoming- S3, vulnerable (NatureServe) 

big bluestem (Andropogon gerardii) BONAP county level distributionmap

 

General Comments

Big bluestem is a dominant component of the tallgrass prairie ecosystem. This species establishes readily from direct seeding, particularly if seeded into crop ground where good weed control has been achieved (i.e. following a glyphosate-resistant crop, for example). It takes two to three years for the stand to develop, with good management and weed control.

 

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:36 in24 in‌12 insolid stand
PLS lbs/acre:  3.64.89.710-12

Seeding depth:1/4-1/2 in 

Seeding method: native seed drill

Seeding time: mid to late spring

Weed control: Prepare clean, firm, weed free seedbed prior to seeding.

 

‌Greenhouse

Seed pre-treatment: No stratification necessary. Germination of grass seed usually improves with proper storage (cool, dry conditions) throughout the first year after harvest.

Sowing: Sow seed in greenhouse 2 months before last frost free date at 1/4 in depth.

Transplanting: Transplant after all danger of frost.

Stand management

Weeds: During establishment -  mow the stand 6-12 in high during first growing season to prevent weed canopy from shading seedlings. Established stand – Atrazine, 2,4-D, Plateau (imazapic), Outlook (Dimethenamid-P).

Pests: Yellow midges may infest florets, reducing seed yields.

Diseases: Smut fungus affects florets.

Seed production

big bluestem (Andropogon gerardii) yield graph

First harvest: Flowering and seed set end of second growing season from direct seeding, 3 years for stand to fill out.

Yield: 60-150 bulk pounds/acre (based on 3 solid stands with no supplemental nitrogen or irrigation; plots were not harvested every year)

Stand life: Peak harvests third year and after. If seed yields decline because stands are sod-bound, they can be chisel plowed to reinvigorate. Annual spring fire when green shoots are 2 in tall helps control weeds and increase flowering and seed production. (Note: This recommendation is strictly for production fields, not remnant prairies). Some producers use nitrogen application in spring to increase seed yield (60-100 pounds lb N/ac). Productive stand life 20 years or more.

Flowering date: early August - mid-September in northern Iowa

Seed maturity/Harvest date: October in northern Iowa

Seed retention: Shattering begins mid to late October. 

Harvest date range at TPC (2003-2022): Sept 12 - Nov 2

Recommended harvest method: Combine at medium to hard dough stage, when some shattering is beginning to occur on the top of the main panicles.

Seed cleaning and storage

Cleaning process: Air-dry material, scalp through 1/2 in mesh, remove awns with debearder or brush machine, then air-screen. Indent cylinder can help remove foxtail or similar weed seeds, if present.

Seed storage: cool/dry (33-50° F, 30-50% RH)

 

Released Germplasm 

Source Identified material: Central (Zone 2), Northern (Zone 1), and Southern (Zone 3) Natural Selections/Iowa Ecotype Germplasm (IA), Northern Missouri Germplasm (MO), OH 370 Germplasm (OH), Southlow Michigan Germplasm (MI), Suther Germplasm (NC)

Selected germplasm: Bounty Germplasm (MN,SD), Hampton Germplasm (MO), OZ-70 Germplasm (AR, IL, MO, OK), Prairie View Indiana Germplasm (IN), Refuge Germplasm (AR, IL, MO, OK)

Cultivated variety (cultivar): Bison (ND), Bonilla (SD), Earl (TX), Kaw (KS), Niagara (NY), Rountree (IA), Sunnyview (SD)

 

References

Chayka, K. (n.d.). Andropogon gerardii (big bluestem). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/big-bluestem 

Hilty, J. (2019). Big bluestem - Andropogan gerardii. Illinois Wildflowers.https://www.illinoiswildflowers.info/grasses/plants/bigblue.htm 

Houseal, G. A. (2007). Grasses warm season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 66–67). Tallgrass Prairie Center - University of Northern Iowa.

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 29, 2024).

USDA-NRCS. (n.d.). Conservation plant releases. Natural Resources Conservation Service. https://www.nrcs.usda.gov/plant-materials/cp/releases 

USDA NRCS National Plant Data Team. (n.d.). Andropogon gerardii Vitman. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=ANGE

Species Guide Updated 12/17/2024

sideoats grama

sideoats grama dickeye
sideoats grama (Bouteloua curtipendula) header

 

Bouteloua curtipendula (Michx.) Torr.

Alternate Common Names: sideoats, side oats grama, side-oats grama

Scientific Synonym: Atheropogon curtipendula

Family:grass family (Poaceae)

Functional Group: warm season grasses

Description 

Life cycle and growth form

Perennial, warm-season bunchgrass, spreading slowly by short rhizomes to form loose colonies.

Height: 1-3 ft  

sideoats grama (Bouteloua curtipendula) whole plant
Leaves and stem
sideoats grama (Bouteloua curtipendula) leaf

Leaves mostly basal with leaf blades 6-8 in long and tapered to a sharp point; stiff hairs with glandular bases evenly spaced along the leaf margins, sticking out at a right-angle from the main axis of the blade; lower leaves curl and turn a light, tawny color when dry; ligule a very short fringe of hair; nodes hairless and green to purple; flowering stem is smooth and erect.

Flower, fruit and seedhead

Fruit/seedhead: Seed head 4-12 in long consisting of many short oat-like spikes (0.5-1.25 in long), each with 3-7 spikelets all turned to one side of the main stem, giving rise to the common name “sideoats;” entire spike falls when mature, leaving a naked stalk with visible nodes.

Pollination: Wind

sideoats grama (Bouteloua curtipendula) inflorescence
Seed

Seed characteristics 

Seeds per ounce: 6,000 (IA NRCS)

Seeds per pound: 96,000 (IA NRCS)

1000 seed weight: 1.30 g (Seed Information Database)

Description: Seed unit is a whole spike, fragment of spike, or floret. Although a seed unit may contain more than one germinable seed, it is counted as a single live seed in the calculation of pure live seed. Caryopsis (grain) 3-4 mm long, smooth brown.

Typical seed test 

PLS: 89% (n = 12)

Purity: 96% (n = 12)

Germination: 59% (n = 11)

Dormant: 34% (n = 11)

(average of n tests of purchased seed lots)

Habitat and range

‌Habitat: Dry to mesic, fine textured, calcium-rich soil; full sun; prairies, bluffs, along railroads, woodland openings. Well-drained soils are preferred for seed production.

Conservation status: Global- G5, secure; District of Columbia- SH, possibly extirpated; Connecticut, Louisiana, Florida, and Michigan- S1, critically imperiled; Georgia, Maryland, Nevada, New York, and Pennsylvania- S2, imperiled; Indiana and West Virginia- S3, vulnerable (NatureServe) 

sideoats grama (Bouteloua curtipendula) BONAP map

 

General Comments

Sideoats grama is an important component of tall and mixed-grass prairies, occurring on well-drained, dry, rocky, alkaline soils. This species establishes readily from direct seeding, particularly if seeded into crop ground where good weed control has been achieved (following a glyphosate-resistant crop, for example). The foliage provides forage for mammalian herbivores as well as specialist and generalist insects, and grassland birds feed on the seeds.

 

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:36 in24 in12 insolid stand
PLS lbs/acre:  3489

Seeding depth: 1/4-1/2 in 

Seeding method: native seed drill

Seeding time: Late spring when soil temperature reaches 55° F.

Weed control: Prepare clean, firm, weed free seedbed prior to seeding.

 

‌Greenhouse

Seed pre-treatment: No stratification necessary. Germination of grass seed usually improves with proper storage (cool, dry conditions) throughout the first year after harvest.

Sowing: Sow seed in greenhouse two months before last frost free date at 1/4 in depth.

Transplanting: Transplant into prepared beds at 12 in spacing after all danger of frost.

Stand management

Weeds: Mow stands high (6-12 in) in first growing season to prevent weed canopy from shading seedlings. Do not use atrazine the year of establishment. On established stands, Plateau (imazapic); Outlook (dimethenamid-P), and 2,4-D have been used. Hand roguing removes weeds that could contaminate seed, cultivation or mowing can be used between rows, and burning in late spring helps control cool season weeds and may prevent buildup of disease inoculum.

Pests: Gall midge larvae have been observed within spikelets.

Diseases: Stem and leaf rust and other fungi are known to occur.

Seed production

sideoats grama (Bouteloua curtipendula) yield graph

First harvest: Flowering and seed set end of second growing season from greenhouse grown transplants.

Yield: 20-255 bulk pounds/acre (per acre yields extrapolated based on production from 3 plots)

Stand life: Peak harvests third year and after. Annual late spring fire when shoots are 1 in tall helps control weeds and increase flowering and seed production.  (Note: This recommendation is strictly for production fields, not remnant prairies.)  Stand should persist 10 years or more if properly matched to soils and well managed.

Flowering date: mid-June - early July in northern Iowa

Seed maturity/Harvest date: September in northern Iowa

Seed retention: Holds seed fairly well, shattering occurs in October. Monitor fields fairly often as they mature and consider harvest when about 10% of stems have lost some spikelets from the top.

Harvest date range at TPC (2003-2023): Sept 1 - Oct 30

Recommended harvest method: Combine at hard dough stage.

Seed cleaning and storage

Cleaning process: Combine-harvested sideoats grama can be air screened initially to sort spikelets from plant fragments. Larger intact spikes can be run quickly through a debearder or hammer mill to break up spikes, and re-air screen. Indent to remove foxtail or other short-seeded weeds.

Seed storage: cool/dry (33-50° F, 30-50% RH)

 

Released Germplasm 

Source Identified material: Central Iowa Germplasm (IA Zone 2), Northern Iowa Germplasm (IA Zone 1), Southern Iowa Germplasm (IA Zone 3), Northern Missouri Germplasm

Selected Germplasm: South Texas Germplasm (TX) 

Cultivated variety (cultivar): Midwest adapted cultivars include El Reno (KS), Haskell (TX), Niner (NM), Pierre (ND), Premier (TX), Vaughn (NM).

Informal Variety: Killdeer (ND)

 

References

Chayka, K. (n.d.). Bouteloua curtipendula (side-oats grama). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/side-oats-grama

Gleason, H. A., & Cronquist, A. (1991). Poaceae. In Manual of Vascular Plants of Northeastern United States and Adjacent Canada (2nd ed., pp. 795-796). The New York Botanical Garden. 

Hilty, J. (2019). Side oats grama - Bouteloua curtipendula. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/so_grama.htm  

Houseal, G. A. (2007). Grasses warm season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 68–69). Tallgrass Prairie Center - University of Northern Iowa.

Kartesz, J.T., The Biota of North America Program (BONAP). 2023. North American Plant Atlas. (http://bonap.net/napa). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2023. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]

NatureServe. 2024. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. (Accessed: February 29, 2024).

USDA NRCS National Plant Data Team. (n.d.). Bouteloua curtipendula (Michx.) Torr. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=BOCU

Species Guide Updated 12/13/2024