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  

Leaves and stem

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

Seed

Appendix D

‌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) 

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 in	24 in	‌12 in	solid stand
PLS lbs/acre:	3.6	4.8	9.7	10-12

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.

‌Appendix A

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

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.

Appendix B

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)

Appendix C

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

Schizachyrium scoparium (Michx.) Nash

Alternate Common Names: prairie beardgrass, broom beardgrass

Scientific Synonym: Andropogon scoparius, Michx.

Family: ‌grass family (Poaceae)

Functional Group: warm season grass

Description 

Life cycle and growth form

Perennial, short rhizomes, fibrous roots, grows in dense clumps.

Height: 1-3 ft  

Leaves and stem

Leaf blades narrow, up to 8 in long, flat or folded lengthwise, green to blue-green in color, usually hairless; sheaths strongly flattened and often hairless; ligule is a fringed (ciliate) membrane; nodes are hairless and purple; flowering stem is hairless and erect with many short branches, bluish to reddish-purple in color.

Flower, fruit and seedhead

Fruit/seedhead: Single spikes, about 1 in long, arise from upper leaf axils, spikelets spread out as they mature, appearing as white, feathery appendages that arch; entire spikelets fall off at maturity and are weakly dispersed by the wind up to several feet from the parent plant.

Pollination: wind

Seed

 

Appendix D

‌Seed characteristics 

Seeds per ounce: 15,000 (IA NRCS)

1000 seed weight: 1.50 g (Seed Information Database)

Description: [shape, length, color, attached structures]

Typical seed test 

PLS: 68% (n = 12)

Purity: 71% (n = 12)

Germination: 35% (n = 11)

Dormant: 59% (n = 11)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Dry to dry-mesic soil; full sun; prairies, glades, dunes, roadsides, along railroads, woodland openings, scrubby barrens, abandoned fields; Wetland Indicator Status is Facultative Upland (FACU) for the Midwest; well-drained, moderately moist soils are preferred for seed production.

Conservation status: Global- G5, secure (NatureServe) 

General Comments

Little bluestem is a dominant component on dry or well-drained soils within the tallgrass prairie region. Careful site selection, seedbed preparation, and weed control are critical to successful establishment from seed. No-till drilling with a native seed drill into cropland following a glyphosate-resistant crop, soybeans for example, is an excellent method. It takes two to three years for a stand to develop and reach peak yields.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	solid stand
PLS lbs/acre:	2.4	3.2	6.4	8.0

Seeding depth: 1/4 in

Seeding method: native seed drill

Seeding time: late spring to early summer.

Weed control: Prepare clean, very 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 after all danger of frost.

‌Appendix A

Stand management

Weeds: Mow stands high (6–12 in) in the first growing season to prevent weed canopy from shading seedlings. Imazepic can be used to control grass and broadleaf weeds in established stands. Pre-emergent grass and broadleaf herbicides can be used for weed control. Always check chemical labels.

Pests: None noted.

Diseases: No significant issues noted in TPC production plots, however, a leaf spot fungus is known to infect little bluestem and related grass species.

Seed production

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

Yield: 30-100 bulk pounds/acre

Stand life: Peak harvests third year and after. If seed yields decline, stands can be chiseled to reinvigorate. We do not apply fertilizer to TPC plots, but this may improve seed yield. Annual late spring fire helps control weeds and increase flowering and seed production. (Note: These recommendations are strictly for production fields, NOT REMNANT PRAIRIES). Productive stand life 10-20 years or more.

Flowering date: Late July to late August.

Seed maturity/Harvest date: Late September to October.

Seed retention: Shattering is moderate, beginning in late September. Much of the variation in seed yield at TPC appears to be due to harvest timing, particularly waiting too long.

Harvest date range at TPC (2003-2022): Sept 5 - Oct 29

Recommended harvest method: Stripper or combine at hard dough to maturity, when most spikes are fluffed out and shattering is just beginning to occur.

Appendix B

Seed cleaning and storage

Cleaning process: Air-dry material, remove awns with a debearder or brush machine, then air-screen. Like other fluffy-seeded warm season grasses, this species may not flow particularly well through the air-screen cleaner.

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

Appendix C

Released Germplasm 

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

Selected germplasm: Badlands Ecotype (ND, SD), Coastal Plains Germplasm (TX, LA), Itasca Germplasm (ND), OK Select Germplasm (OK), Ozark Germplasm (MO, IL), Prairie View Indiana Germplasm (IN), STN-176 Germplasm (TX), STN-461 Germplasm (TX)

Cultivated varieties (cultivars): Ahring (Great Plains), Aldous (KS), Cimarron (OK, KS), Pastura (NM), Sims (Great Plains)

References

Chayka, K. (n.d.). Schizachyrium scoparium (little bluestem). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/little-bluestem 

Hilty, J. (2019). Little bluestem - Schizachyrium scoparium. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/little_bluestem.htm 

Houseal, G. A. (2007). Grasses warm season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 72–73). 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.). Schizachyrium scoparium (Michx.) Nash. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=SCSC 

USDA NRCS. Prairie View Indiana Germplasm Little Bluestem [Infographic] Retrieved February 20, 2025 from https://efotg.sc.egov.usda.gov/references/public/IN/Revised_Prairie_View_Little_bluestem.pdf 

Wipff, J. K. (2021, May 11). Schizachyrium scoparium (Michx.) Nash. Flora of North America. http://floranorthamerica.org/Schizachyrium_scoparium

Species Guide Updated 11/17/2025

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  

Leaves and stem

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

Seed

Appendix D

‌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) 

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 in	24 in	12 in	solid stand
PLS lbs/acre:	3	4	8	9

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.

‌Appendix A

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

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.

Appendix B

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)

Appendix C

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

Panicum virgatum, (L.) 

Alternate Common Names: thatchgrass, Wobsqua grass, blackbent, tall panic grass, old switch panicgrass

Scientific Synonyms: Panicum virgatum var. spissum, Panicum virgatum var. cubense, Panicum bavardii

Family: ‌grass family (Poaceae)

Functional Group: warm season grass

Description 

Life cycle and growth form

Warm season perennial, rhizomatous, forms clonal patches with many stems that expand over time.

Height: 3-6 ft  

Leaves and stem

Leaf blades 5/16 in wide and 6-22 in long, often hairy on the upper surface, especially near the ligule, ligule is fringe of dense hairs about 1/8 in tall; stem erect and hairless.

Flower, fruit and seedhead

Fruit/seed head: Seedhead is an openly branched, airy panicle 8-16 in long with green to purple spikelets near the ends of the branches.

Pollination: wind

Seed

 

Appendix D

‌Seed characteristics 

Seed weight: 

Seeds per ounce: 14,000 (IA NRCS)

Seeds per pound: 259,000 (IA NRCS)

1000 seed weight: 1.30 g (Seed Information Database)

Description: Spikelet is two-flowered with the fertile floret uppermost, smooth, awnless. Grain is shiny, smooth, 3-4 mm (about 1/8 in) long.

Typical seed test 

PLS: 91% (n = 9)

Purity: 97% (n = 9)

Germination: 49% (n = 7)

Dormancy: 44% (n = 7)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Mesic to wet-mesic soil; full sun; prairies, savannas, streambanks, shorelines, dunes, woodland openings, roadsides, along railroads, ditches; may become abundant in disturbed prairies, much less common in high quality prairies. Wetland Indicator Status is Facultative (FAC) for the Midwest. Fertile, well-drained soils are preferred for seed production.

Conservation status: Global- G5, secure; Nevada- S2, imperiled; Vermont and Wyoming- S3, vulnerable (NatureServe) 

General Comments

A number of cultivars of switchgrass have been developed for forage and seed production, winter hardiness, and grazing tolerance by the USDA-NRCS Plant Materials program. These cultivars have been planted widely as monocultures and in early prairie reconstructions.  Because seed has been commercially available at affordable prices for decades, it was usually seeded heavily and tended to dominate stands. For these reasons it has been considered aggressive. Switchgrass can form dense colonies on lowland prairies, but is usually uncommon on high-quality remnant upland prairies and tends to occur in isolated patches near disturbance activities such as gopher mounds (Weaver 1954). Switchgrass establishes readily from seed, and is relatively easy to harvest and clean.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	Solid Stand
PLS lbs/acre:	2.6	3.5	6.0	6.0

Seeding depth: 1/4 in 

Seeding method: Native seed drill or broadcast seed and cultipack for solid stand.

Seeding time: Spring

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

 

‌‌Greenhouse

Seed pre-treatment: Moist stratify seed for 4 weeks to improve germination.

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

Transplanting: Transplant after all danger of frost into rows convenient for tillage equipment.

‌Appendix A

Stand management

Weeds: Mow stands high (6-12 in) first growing season to prevent weed canopy from shading seedlings. Broadleaf herbicides can be used to control broadleaf weeds in established stands. Switchgrass is atrazine resistant, and can be applied at the label rate at planting time. Read and follow label instructions.

Pests: None noted.

Diseases: Seed smut, if left unchecked, can seriously decrease seed yields on switchgrass. The smut is caused by a fungus, Tilletia maclaganii. Glumes may exhibit an uncharacteristic purple coloration, and seeds are replaced by fungal spores that are red-orange when immature turning dark brown at maturity. Fields may need to be destroyed or relocated if diseased (NRCS 2003).

Seed production

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

Yield: 150-350 bulk pounds/acre (per acre yields extrapolated based on harvests of 2 plots)

Stand life: Stands should persist 10-15 years or more. Good seed production second year and after.

Flowering date: late July - early September in northern Iowa

Seed maturity/Harvest date: September in northern Iowa

Seed retention: Shattering begins in late September to early October

Harvest date range at TPC (2003-2010): Sept 16 - Nov 2

Recommended harvest method: Combine at hard dough stage before significant shattering has occurred. 

Appendix B

Seed cleaning and storage

Cleaning process: Pre-clean air-dried material by scalping thru 1/2 in and 1/4 in mesh to remove large particles. Brush to remove all floral parts from the grain, air-screen to clean.

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

Appendix C

Released Germplasm 

Source Identified material:  Natural Selections/Iowa Ecotype Projects Zones 1 (northern Iowa), 2 (central Iowa), and 3 (southern Iowa)

Cultivated varieties (cultivars): Mid-west adapted include Blackwell (KS), Cave-In-Rock (IL), Dacotah, Forestburg (ND), Nebraska 28 (NE), Shawnee (MO)

References

Chayka, K. (n.d.). Panicum virgatum (switchgrass). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/switchgrass 

Freckmann, R. W. & Lelong, M. G. (2021, May 11). Panicum virgatum L. Flora of North America. http://floranorthamerica.org/Panicum_virgatum  

Hilty, J. (2019). Switch grass - Panicum virgatum. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/switchgrass.htm 

Houseal, G. A. (2007). Grasses warm season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 70–71). 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.). Panicum virgatum L. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=PAVI2

Species Guide Updated 12/5/2025