Elymus canadensis L. 

Alternate Common Name(s): nodding wildrye, western wildrye, great plains wildrye

Scientific Synonym(s): Elymus brachystachys Scribn. & C.R. Ball, Elymus canadensis L. var. brachystachys  (Scribn. & C.R. Ball) Farw., Elymus canadensis L. var. hirsutus (Farw.) Dorn, Elymus canadensis L. var. robustus (Scribn. & J.G. Sm.) Mack. & Bush, Elymus crescendus L.C. Wheeler, Elymus philadelphicus L., Elymus philadelphicus L. var. hirsutus Farw., Elymus robustus Scribn. & J.G. Sm.

Family: ‌grass family (Poaceae)

Functional Group: cool season grasses

Description 

Life cycle and growth form

Perennial, cool-season bunchgrass, weak to no rhizomes.

Height: 1-5 ft  

Leaves and stem

Leaf blades up to 16 in long, 1/4-3/4 in wide, ligule a short (up to 1 mm) membrane, sheaths usually smooth with two small, purplish to brown lobes (auricles) clasping stem where the sheath meets the blade, nodes hairless and hidden under the sheaths; stems smooth, erect, unbranched.

Flower, fruit and seedhead

Fruit/seedhead: Seedhead a thick, bristly spike, 3-10 inches long, usually nodding, light tan when mature, each spikelet with a pair of awned glumes (up to 1.5 in including the awn) and 3-5 florets, lemmas (chaffy parts around the grain) also awned (up to 2.5 in including the awn), awns twist and curve outward when dry, florets drop when mature, leaving glumes on the stalk.

Pollination: wind

Seed

Appendix D

‌Seed characteristics 

Seeds per ounce: 5,200 (IA NRCS)

Seeds per pound: 83,200 (IA NRCS)

1000 seed weight: 4.50 g (Seed Information Database)

Description: The long, barbed awns make this species difficult to clean. Curved awns on lemmas are up to 5 cm (2 in). Glumes taper to awns 1-3 cm (1/2-1.25 in) long. Caryopsis dark brown at maturity, 5-8 mm long.

Typical seed test 

PLS: 88%

Purity: 96%

Germination: 66%

Dormant: 19%

(averages obtained from 12 tests of purchased seed lots)

Habitat and range

‌Habitat: Broadly adapted to a range of conditions: dry to moist soil; partial to full sun; prairies, savannas, woodland edges, bluffs, dunes, riverbanks, upland and lowland, open areas, disturbed areas. Wetland Indicator Status is Facultative Upland (FACU) for the Midwest. Well-drained, loamy soils are preferred for production.

Conservation status: Global- G5, secure; Maine- SH, possibly extirpated; Nevada and Virginia- S1, critically imperiled (NatureServe) 

General Comments

Canada wildrye is a relatively short-lived perennial bunchgrass which establishes readily from seed in mixed plantings. These two traits make it ideally suited as a nurse crop for prairie restorations. It can also be direct-seeded as a seed production field into a well-prepared, weed-free seed bed (e.g., following a glyphosate-resistant crop).

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	solid stand
PLS lbs/acre:	7	10.5	21	21

Seeding depth: 1/4-1/2 in

Seeding method: native seed drill

Seeding time: Fall, or early spring preferred.

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 at 12 in spacing in prepared beds after all danger of frost.

‌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.

Pests: None noted.

Diseases: Susceptible to leaf and stem rust, also ergot.

Hybridization risk: This species is known to hybridize with related species Elymus hystrix, E. villosus, E. virginicus

Seed production

First harvest: Flowering and seed set will occur at the end of the first growing season from previous fall seeding or early spring seeding, or late spring transplants.

Yield: 35-370 bulk pounds/acre (per acre yield extrapolated from 3 plots)

Stand life: 4-6 years. Seed production declines significantly in the fifth year and after. Annual fall burning will prolong stand life and seed yield.

Flowering date: mid-July to mid-August in northern Iowa

Seed maturity/Harvest date: September in northern Iowa

Seed retention: shattering occurs early to mid-October

Harvest date range at TPC (2003-2010): Sept 7 - Nov 4 

Recommended harvest method: Combine at maturity (hard dough stage). Long, barbed awns make harvesting a challenge, causing seed to ball up and not flow. Additional de-awning bars or other modifications to the combine may be required for successful harvest of this species.

Appendix B

Seed cleaning and storage

Cleaning process: Debeard or brush to remove long awns and make the material flowable. Air-screen to clean (See Appendix C for settings).

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)

Selected Germplasm: Lavaca Germplasm (TX)

Cultivated variety (cultivar): Mandan (ND) 

Tested: Icy Blue Germplasm (MI)

References

Barkworth, M. E., Campbell, J. J.N., & Salomon, B. (2021, May 11). Elymus canadensis L. Flora of North America. http://floranorthamerica.org/Elymus_canadensis 

Chayka, K. (n.d.). Elymus canadensis (Canada wild rye). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/canada-wild-rye 

Cochrane, T. S., Elliot, K., & Lipke, C. S. (2014). Canada wild-rye. In Prairie plants of the University of Wisconsin-Madison Arboretum (3rd ed., p. 264). University of Wisconsin-Madison Arboretum.

Great Plains Flora Association. (1991). Grass family. In T. M. Barkley, R. E. Brooks, & E. K. Schofield (Eds.), Flora of the Great Plains (2nd ed., p. 1167). University Press of Kansas.

Houseal, G. A. (2007). Grasses cool season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 84–85). 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.). Elymus canadensis L. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=ELCA4

Species Guide Updated 01/31/2025

Elymus virginicus L.

Alternate Common Name: Terrell grass

Family: ‌grass family (Poaceae)

Functional Group: cool season grasses

Description 

Life cycle and growth form

Perennial, cool season bunchgrass with fibrous roots.

Height: 1-4 ft  

Leaves and stem

Leaf blades mostly flat but sometimes with inrolled edges, rough textured, 12-35 cm (5-14 in) long and 5-15 mm (1/4-5/8 in) wide, sheath sometimes with fine hairs; ligule a short membrane bracketed by two small, often purplish projections (auricles) that may wrap partway around the stem. Stems unbranched, smooth and erect, multiple from the base making clumps.

Flower, fruit and seedhead

Fruit/seedhead: Seed head is an erect spike 5-17 cm (2-7 in) long  (distinguishing it from Canada wildrye which has drooping spikes), often partially enclosed in the uppermost, inflated leaf sheath, light straw-colored at maturity. Spikelets bear awns up to 1 in long. Spikelets eventually drop off, leaving a naked stalk with alternating nodes.

Pollination: wind

Seed

 

Appendix D

‌Seed characteristics 

Seed weight: 

Seeds per ounce: 4,200 (IA NRCS)

Seeds per pound: 67,200 (IA NRCS) 

1000 seed weight: 6.14 g (Seed Information Database)

Description: Typical seed unit is a spikelet with 2-3 florets, awned, 0.5-2 cm (1/4-7/8 in) long including awns. Empty scales (glumes) on either side of spikelet thickened, rigid, awned, up to 2.5 cm long (1 in) long including awn. Awn length is highly variable in this species.

Typical seed test 

PLS: 96% 

Purity: 98%

Germination: 48%

Dormant: 51%

(averages obtained from 9 tests of purchased seed lots)

Habitat and range

‌Habitat: Mesic to wet-mesic soil with high fertility; light shade to full sun; deciduous forests, savannas, thickets, meadows near woodlands. Wetland Indicator Status is Facultative Wetland (FACW) for the Midwest. Well-drained loams are preferred for seed production.

Conservation status: Global- G5, secure (NatureServe) 

General Comments

Virginia wildrye is commonly found in open forests, savannas, and along woodland edges, and can be particularly abundant in open forests along creeks and rivers. It readily establishes from seed, and holds promise as a nurse crop for prairie and savanna reconstructions. Because of its shade tolerance, it will spread in open woodlands, but eventually gives way to full-sun adapted prairie species in a prairie reconstruction.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	Solid Stand
PLS lbs/acre:	8.6	11.5	23	20-35

Seeding depth: 1/4-1/2 in

Seeding method: native seed drill

Seeding time: Fall or early spring

Weed control: Prepare clean, firm, weed free seedbed prior to seeding (e.g., following a glyphosate-resistant crop, for example).

 

‌‌Greenhouse

Seed pre-treatment: No moist stratification is 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 1/4-1/2 in depth.

Transplanting: Transplant after all danger of frost into rows spaced convenient for tillage equipment or at 12 in spacing in a weed barrier.

‌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. Cultivate or mow between rows.

Pests: Grubs are reportedly a problem in Texas.

Diseases: Ergot is known to occur on seedheads.

Hybridization risk: This species is known to hybridize with related species Elymus canadensis, E. hystrix, E. villosus. Maintain adequate separation between plots of these species.

Seed production

First harvest: Abundant flowering and seed set end of first growing season from greenhouse grown plugs transplanted into a weed barrier.

Yield: 355-775 bulk pounds/acre (per acre yields extrapolated from production on 3 plots)

Stand life: Estimated stand life 5-8 years. Annual early spring burn will prolong the life of the stand.

Flowering date: mid-July to mid-August in northern Iowa

Seed maturity/Harvest date: late August to early September in northern Iowa

Seed retention: Shattering occurs mid to late October; fairly low risk of seed loss.

Harvest date range at TPC (2006-2025): Aug 14 - Nov 22

Harvest date range at Elsberry, MO: Aug 29 to Sept 12

Recommended harvest method: Combine at hard dough stage. 

Appendix B

Seed cleaning and storage

Cleaning process: Pre-clean air-dried material by scalping through 1/2 in mesh to remove large chopped stems and leaves. Debeard or brush gently to remove awns and break up seed heads, then airscreen to clean (see Appendix C for settings).

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

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Project Zones 1, 2, and 3. Northern Missouri Germplasm

Selected Germplasm: Cuivre River Germplasm (MO), Kinchafoonee Germplasm (TX), Tober Germplasm (ND)

References

Chayka, K. (n.d.). Elymus virginicus (Virginia wild rye). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/virginia-wild-rye 

Hilty, J. (2019). Virginia wild rye - Elymus virginicus. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/va_rye.htm 

Houseal, G. A. (2007). Grasses cool season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 86–87). 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.). Elymus virginicus L. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=ELVI3

Species Guide Updated 12/3/2025

Calamagrostis canadensis (Michx) P. Beauv. 

Alternate Common Names: bluejoint reedgrass, Canada bluejoint, Canada reedgrass, marsh reedgrass, meadow pinegrass

Scientific Synonym: Calamagrostis anomala

Family: ‌grass family (Poaceae)

Functional Group: cool season grasses

Description 

Life cycle and growth form

Perennial, rhizomatous grass that forms spreading, hummocky colonies.

Height: Flowering culms 3-5 ft tall 

Leaves and stem

‌

Leaf blades up to 12 in (30 cm) long and 3/16-3/8 in (3-8 mm) wide, leaf sheaths smooth with prominent veins; ligule is membranous, about 1/8 in (3 mm) tall; stems and nodes are hairless; dead leaves and stems accumulate from year to year in absence of fire, forming tussocks.

Flower, fruit and seedhead

Fruit/seedhead: Mature seed head is a pale gold, loosely branched, plume-like panicle 4-8 in long (10-20 cm), tending to nod to one side; short “flag leaf” just below panicle tends to stick out at a 90 degree angle from the stem; florets fall off when mature, leaving glumes on the stalks.

Pollination: Wind

Seed

Appendix D

‌Seed characteristics 

Seed weight: 

Seeds per ounce: 280,000 (IA NRCS)

Seeds per pound: 4,480,000 (IA NRCS)

1000 seed weight: 0.32 g (Seed Information Database)

Description: Spikelets about 2 mm (3/32 in) long. Grain (caryopsis) about 1/32-1/16 in (1 mm) long, with tuft of hairs at the base slightly shorter than the grain.

Typical seed test 

PLS: 90%

Purity: 95%

Germination: 73%

Dormant: 22%

(averages obtained from 4 tests of purchased seed lots)

Habitat and range

‌Habitat: Wet-mesic to wet soil; full sun; bogs, marshes, wet swales, along rivers and streams. Tolerates acidic soils up to pH 8 conditions; can tolerate anaerobic (low oxygen) conditions; prefers nutrient-rich, seasonally-inundated soils; irrigation is essential for optimal seed production on upland sites. Wetland Indicator Status is Obligate Wetland (OBL) for the Midwest.

Conservation status: Global- G5, secure; North Carolina, Delaware, and Kansas- S1, critically imperiled; Illinois- S3, vulnerable (NatureServe)

General Comments

Bluejoint is a highly rhizomatous species forming large colonies in preferred habitats, occupying sites even more wet than prairie cordgrass (Spartina pectinata) seems to prefer. Like prairie cordgrass, seed production occurs mostly on the outer edges of colonies, and is generally low. Bluejoint is best propagated in controlled conditions of the greenhouse, and transplanted into wide row spacings.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Not recommended for this species

 

‌‌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 on surface of growing mix in greenhouse two months before last frost free date. Water carefully with a mist wand to avoid dislodging seed.

Transplanting: Transplant after all danger of frost. Greenhouse grown plugs can be transplanted into wide row spacing, 6-8 ft between rows, and plants should be 1-2 ft apart within the rows. This gives the newly established plants adequate root-space for rhizome spread, and promotes more flowering and seed set after establishment. Irrigate during establishment and as needed for flowering and seed production.

‌Appendix A

Stand management

Weeds: Pre-emergent herbicides can be used after transplanting seedling plugs or pieces of rhizome. It’s critical to water-in transplants to seal soil around roots to prevent herbicide from coming into contact with and possibly damaging roots.

Pests: Nematode (Subanguina calamagrostis) invades leaf tissue and form galls, causing leaves to twist, and allowing subsequent infection by a fungus (Norton 1987).

Diseases: None noted.

Seed production

First harvest: Plants remain vegetative first growing season. Some flowering and seed set in the second growing season from greenhouse grown transplants.

Yield: 0.4-8.2 bulk pounds/acre (yields extrapolated based on production from 3 plots); commercial growers can achieve yields of 20-50 pounds per acre (USDA Plants Guide)

Stand life: Stands are long-lived in proper soils/hydrology. Seed production declines as stands become sod-bound in approximately 4-5 years. Flowering is patchy within a stand and may be higher on the edges of clones.

Flowering date: mid to late June in northern Iowa

Seed maturity: early July in northern Iowa

Seed retention: Shattering occurs soon after maturity, and seed is windblown. Monitor frequently for ripeness and be ready to harvest when inflorescences turn pale, fluffy, and open. The glumes stay on the plant when the seed drops, so seed heads can appear full even after they have shed much of their seed.

Harvest date range at TPC (2003-2008): June 29 - July 10

Recommended harvest method: Hand harvest or combine at maturity, but before dispersal. The seed is very light and wind-dispersed. Turn off air when combining.

Appendix B

Seed cleaning and storage

Cleaning process: Thresh hand-collected material through 1/4 in screen. Brush seed to remove tuft of hairs at base of florets to improve flow of seed through airscreen (see settings in Appendix C).

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

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Zones 1, 2, and 3

Cultivated variety (cultivars): Sourdough (AK)

References

Alaska DNR. (2007). ‘Sourdough’ Bluejoint Reedgrass Calamagrosis canadensis. [Infographic]. dnr.alaska.gov. https://dnr.alaska.gov/ag/akpmc/pdf/plant-flyers/SourdoughBluejoint.pdf 

Chayka, K. (n.d.). Calamagrostis canadensis (Canada bluejoint). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/canada-bluejoint

Hilty, J. (2019). Bluejoint grass - Calamagrostis canadensis. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/bluejoint.html 

Houseal, G. A. (2007). Grasses cool season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 82–83). 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)]

Marr, K. L., Hebda, R. J., & Greenef, C. W. (2021). Calamagrostis canadensis (Michx.) P. Beauv. Flora of North America. http://floranorthamerica.org/Calamagrostis_canadensis  

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).

Norton, D.C., Cody, A.M., Gabel, A.W. (1987) Subanguina calamagrostis and Its Biology in Calamagrostis spp. in Iowa, Ohio, and Wisconsin. The Journal of Nematology, 19(2), 260-262. https://pmc.ncbi.nlm.nih.gov/articles/PMC2618621/

USDA NRCS National Plant Data Team. (n.d.). Calamagrostis canadensis (Michx.) P. Beauv. USDA plants database. https://plants.usda.gov/plant-profile/CACA4

Wynia, R.L. (2006, March 07) Bluejoint Reedgrass Calamagrostis canadensis (Michx.) Beaux. USDA NRCS Plant Guide. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_caca4.pdf

Species Guide Updated 12/1/2025

Koeleria macrantha (Ladeb.) Schult. 

Alternate Common Names: June grass, Junegrass, crested hair grass, Koeler’s grass

Scientific Synonyms: Koeleria albescens auct., Koeleria cristata auct. non Pers. p.p., Koeleria cristata Pers. var. longifolia Vasey ex Burtt Davy, Koeleria cristata Pers. var. pinetorum Abrams, Koeleria gracilis Pers., Koeleria nitida Nutt., nom. utique rej., Koeleria pyramidata auct. non (Lam.) P. Beauv. p.p., Koeleria yukonensis Hultén, Koeleria nitita, Koeleria cristata Pers. var. pubescens, Koeleria cristata Pers. var. major

Family: ‌grass family (Poaceae)

Functional Group: cool season grasses

Description 

Life cycle and growth form

Perennial, cool-season bunchgrass with fibrous roots.

Height: 0.5-2 ft  

Leaves and stem

‌

Leaves mostly basal in a distinct tuft, leaf blades 3-25 cm long (1.25-10 in) and 1-4 mm wide (up to 3/16 in), leaf sheaths short-hairy to smooth, with hairs on the margins of the collar, ligule a short (<1 mm), ragged membrane; stem with fine hairs at base of seedhead and at nodes.

Flower, fruit and seedhead

Fruit/seedhead: Light tan spike-like panicle 3-18 cm long (1.25-7.25 in) and 1-3 cm wide (0.5-1.25 in), stem covered in fine hairs below the seed head. At maturity, seed drops off with surrounding chaffy parts (lemma and palea), but glumes (chaffy parts below the flowers) stay on the stalk.

Pollination: wind

Seed

 

Appendix D

‌Seed characteristics 

Seed weight: 

Seeds per ounce: 200,000 (IA NRCS)

Seeds per pound: 3,200,000 (IA NRCS)

1000 seed weight: 0.30 g (Seed Information Database)

Description: Seed unit is a grain about 2-3 mm long (1/8 in), with or without surrounding chaffy parts (lemma and palea).

Typical seed test 

PLS: 69% (n = 10)

Purity: 76% (n = 10)

Germination: 68% (n = 9)

Dormant: 1% (n = 9)

(averages obtained from n tests of purchased seed lots)

Habitat and range

‌Habitat: Full sun. Found in dry, upland, rocky or sandy prairies, becoming more abundant on northern prairies. Very well-drained soils are preferred for seed production.

Conservation status: Global- G5, secure; Pennsylvania- SX, presumed extirpated; Alaska, Kentucky, and Louisiana- S1, critically imperiled; Arkansas and Ohio- S2, imperiled; Nevada- S3, vulnerable (NatureServe)

General Comments

Prairie Junegrass is an important cool-season grass component, particularly in prairies on dry, very well-drained sites. Plants are of medium longevity, poorly tolerant of competition, and may rely on reseeding to persist.

Recommendations for Seed Production 

Establishment for seed production

‌Direct seeding

Row spacing:	36 in	24 in	12 in	Solid Stand
PLS lbs/acre:	0.25	0.4	0.75	0.75-1.0

Seeding depth: 1/8 in (light needed for germination)

Seeding method: native seed drill

Seeding time: Late spring

Weed control: Good weed control before seeding is essential. Seedlings are small and slow growing and vulnerable to competition from weeds as well as to mechanical damage from equipment or foot traffic.

 

‌‌Greenhouse

Seed pre-treatment: No stratification necessary, although we have observed improved speed and uniformity of germination following 30-day cold/moist stratification. Germination of grass seed usually improves with proper storage (cool, dry conditions) throughout the first year after harvest.

Sowing: Sow seed on top of soil (or cover only very lightly, seeds require light to germinate) in a greenhouse 8-12 weeks before the last frost free date. Water (or mist) very gently to avoid splattering or floating seeds out of the potting medium.

Transplanting: Transplant into a weed barrier 8-12 in apart after all danger of frost.

‌Appendix A

Stand management

Weeds: For plantings in weed barrier, hand rogue weeds while small, being careful not to uproot young seedlings. For direct seeded stands, mow stand high (6–12 inches) in first growing season to prevent weed canopy from shading seedlings. Cultivate or mow vegetation between rows. Broadleaf herbicides can be used to control broadleaf weeds in established stands. Non-native perennial cool-season grasses such as Kentucky bluegrass (Poa pratensis) and smooth brome (Bromus inermis) invade plantings and can outcompete Junegrass, causing declines in production.

Pests: Grubs are reportedly a problem in Texas. 

Diseases: Ergot is known to occur on seedheads.

Seed production

First Harvest: Flowering and seed set at end of second growing season from greenhouse grown transplants. Plants will remain vegetative the first growing season. 

Yield: 10-175 pounds/acre (averages extrapolated from 3 plots)

Stand life: Potentially 4-5 years. Peak harvests occur in second and third year, after which seed production declines significantly. Invasion by non-native cool-season grasses is one cause of yield decline.

Flowering Date: early to late June in northern Iowa

Seed maturity/Harvest date: late June - early July in northern Iowa. Regularly monitor plots for maturity as seed heads change from green to straw colored. Tap seed heads lightly on hand and observe for shattering. 

Seed retention: Shattering occurs mid to late July

Harvest date range at TPC (2003-2023): June 22 - July 8

Recommended harvest method: Combine harvesting is practical for larger plots. Swathing/windrowing before combining may improve threshing, uniformity of seed maturation, and reduce shattering due to wind. A modified hedge-trimmer with an attached collection tray works for harvesting small plots. 

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 pieces of stems and leaves. Run through a brush machine to break up seed heads, then air-screen to clean (see appendix for settings).

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

Appendix C

Released Germplasm 

Source Identified material: Natural Selections/Iowa Ecotype Project Zone 1 (northern Iowa) and Zone 2 (central Iowa)

References

Chayka, K. (n.d.). Koeleria macrantha (Junegrass). Minnesota Wildflowers. https://www.minnesotawildflowers.info/grass-sedge-rush/junegrass 

Hilty, J. (2019). June grass - Koeleria macrantha. Illinois Wildflowers. https://www.illinoiswildflowers.info/grasses/plants/june_grass.htm

Houseal, G. A. (2007). Grasses cool season. In G. A. Houseal (Eds.), Tallgrass Prairie Center’s native seed production manual (pp. 88–89). 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).

Runkel, S. T., & Roosa, D. M. (2009). June grass. In Wildflowers of the tallgrass prairie: The upper Midwest (2nd ed., pp. 106–107). University of Iowa Press.

Standley, L. A. (2021, May 11). Koeleria macrantha (Ledeb.) Schult. Flora of North America. http://floranorthamerica.org/Koeleria_macrantha 

USDA NRCS National Plant Data Team. (n.d.). Koeleria macrantha (Ledab.) Schult. USDA plants database. https://plants.usda.gov/home/plantProfile?symbol=KOMA

Species Guide Updated 12/04/2025