Panicum virgatum

old switch panic grass, switchgrass, wand panic grass


Leaf Arrangement


Leaf Margin


Leaf Type


Leaf Shape


Growth Form


Flower Color


Flower Month

June - October

Height (meters)

0.3 - 2.4

Milky Sap








Growing Season

Warm season

Wetland Class


Wetland Coefficient of Conservatism


Prairie Coefficient of Conservatism


Field Characters

Identification tip: Switch grass is a large, coarse, usually bluish colored grass with large, wide, erect leaves and a distinctive ligule. When sterile it can be confused with Paspalum floridanum which has a membranous, pointed ligule and Sorghastrum nutans, which is easily identified by its claw-like ligule and prominent auricles (ear-like structures) at its leaf collars. Small, sterile specimens could be confused with Panicum anceps which can be distinguished by a gleaming white midrib and satiny sheath linings.

Cultural Information

Switchgrass is readily propagated by root cuttings, division, or seed. Seed viability was found to be 60-80% in plants growing on Louisiana prairie remnants in 1996. Care should be used when including switchgrass seed in a seed mixture for restoration. Due to its aggressiveness it can dominate and overpower other species. Harvest seed beginning in September. Strip seed from heads by hand or with mechanical seed strippers. Commercial seeds have a purity of 95%, a germination rate of 75%, and have 288,000 - 389,000 seeds/lb. the seed of wild populations can be quit variable ranging up to 1,000,000 seeds/lb. The recommended seeding rate is 5-8 lbs/acre. Seed germination for most members of the panicum is improved by cold/moist stratification, although many may be planted fresh (Steffen 1997). Propagation Goal: Plants Propagation Method: Seed Product Type: Container (plug) Stock Type: 1+0 container plugs Time To Grow: 11 Months Target Specifications: Height: n/a, herbaceous perennial. Caliper: n/a, herbaceous perennial. Root System: firm root plug. Propagule Collection: Seed is harvested by combine about Sept. 18. It is ready when it no longer has a soft, creamy center. Propagule Processing: Seed sizes change from year to year, so it is important to experiment with screens and techniques. First, run the seed through the Debearder with the middle screen size and the brushes set out 1/4 inch. Run it through the Crippen with a top screen of 15, middle screen of 10, and bottom screen solid. Next, run the good seed back through the Debearder, then through the Crippen again with a top screen of 12, middle screen of 10, and bottom screen of 1/25. Finally, try running the good seed over the Forsberg gravity table. Seed purity varies from year to year and should be sent out for testing. Pre-Planting Treatments: 8 ounces of seed is saved to sow one bench in either 64 flats of the Multipot #6, or 24 flats of the Multipot #3 or #4. Seed is damp stratified by mixing it with equal amounts of vermiculite and lightly dampening in a plastic bag or container. Store this seed for 3-4 months in a cold room of 34-36 degrees F. Propagation Environment: Fully controlled greenhouse. Container Type and Volume: Multipot #3, #4, or #6 are used. Cell volumes are 6, 9, and 6 cubic inches, respectively. Growing Media: Sterile, Pro-Mix PGX. Add vermiculite and perlite at a 10:1 ratio. Do not add slow release fertilizer to the grasses, as it tends to burn the young, tender roots. Ensure flats are tapped down to prevent settling. Total Time to Harvest: 7-11 months, depending on weather and plant/root development. Sowing Date: Three crops are started in the greenhouse with the first in late December and the last no later than the end of March. Sowing/Planting Technique: Sow the seeds by hand by broadcasting. Try to sprinkle 3-5 seeds per cell. Seed purity rates vary from year to year. Cover the seeds to one times their depth with the same growing media. Use a dibble board or roller to gently press seed and cover soil in the cell. Establishment Phase: Set the greenhouse temperatures to be 70-80 degrees during the day, and 65-75 degrees at night. 75% germination is reached in about one week. Plants must be watered by hand during germination. Set the hose on gentle shower to prevent the seeds from splashing out. Active Growth Phase: Once germination is successful, the greenhouse temperature may be turned down gradually depending on outside temperatures. Plants are irrigated in the morning by soaking for 20 to 30 minutes. This allows the foliage to dry out during the day. Once true leaves appear, not cotyledons, the plants may be fertilized. Start with 50 ppm of Rapid Grow or Peter's Liquid Fertilizer once a week. This rate is increased to 200 ppm gradually, and, again, decreased to 50 ppm before moving the plants outside to the shadehouse. It is important to rinse fertilizer residue off the foliage by running the irrigation for 30 seconds. Grasses are not thinned. When foliage reaches 8 to 10 inches, the plants need to be pruned back to 3 or 4 inches. This is accomplished by turning the flats on their sides and cutting with scissors or sheers. Make sure the clippings are all removed from the flats to prevent disease spread. Hardening Phase: The first greenhouse crop will be moved to a hoop house in late January to February. To acclimate the plants, the irrigation rate is reduced to 50 ppm before moving and greenhouse temperatures are decreased to 55-60 degrees day. The second and third crops are moved directly to the shadehouse in April and May. Again, greenhouse controls and fertilization rates are adjusted in preparation for the move. Plants that reach 8-10 inches in the shadehouse will require pruning also. Harvesting, Storage and Shipping: Harvest Date: Flats may be unplugged in October or November as long as most of the tops have died down. Storage Conditions: Plugs that are not shipped during this fall's planting season may be stored for spring planting in cold rooms above freezing, preferably 40-50 degrees. Try to remove most of the dead foliage as you can before bagging the root plugs for storage. Store them on plastic bags to ensure the roots do not dry out. Storage Duration: Approximately 4 to 6 months. Plugs may be shipped at any time as long as the receiver has cold storage. Length of Storage: 4 to 6 months Outplanting performance on typical sites: Outplanting Site: Illinois prairie sites to include State Parks, highway roadsides, and limited private lands. Prefers wet prairies. Outplanting Date: September to November (Flood, Blessman, and Horvath 2001)

Animal Use

This information is for the genera Panicum and Dicanthelium with note that, because of abundance and distribution, it is one of the country's most important food sources for ground-feeding songbirds and gamebirds. It is a preferred forage by cattle but is not as palatable as big bluestem in prairie. Animals that eat its seeds: Purple gallinule, Sora rail, Pectoral sandpiper, Ground dove, Mourning dove, Eastern white-winged dove, Bobwhite quail, Wild turkey, Woodcock, Redwing blackbird, Painted bunting, Cardinal, Cowbird, Brown creeper, Dickcissel, Blue grosbeak, Junco, Meadowlark, American and sprague pipit, Pyrrhuloxia, Chipping, vesper and white-throated sparrows, Pine-woods and tree sparrow, English, Harris, Henslow, Ipswich and sharp-tailed sparrows, Field, grasshopper, song, swamp and white-crowned sparrows, Savannah sparrow, Towhee, Pine warbler. Animals that eat the young plants and its seed: Baldpate and blue-winged teal, Florida and green-winged teal, Gadwall duck, Blue and canada goose, Snow goose, White-fronted goose. Animals that eat the plants: Antelope, White-tailed deer (Martin et al. 1951).

Natural History

Warm-season, sod-forming, perennial grass with vigorous scaly rhizomes, often forming large, dense colonies. It grows throughout the bluestem belt of eastern and central Great Plains and on certain prairie sites in other parts of the United States. Charles Allen (unpublished data) found it to be the dominate grass on Louisiana's railroad remnants. It is adapted to a wide range of soil and climatic conditions but prefers moist soils in low areas. Two distinct strains are recognized: an upland and bottomland. The bottomland strain has a much coarser stem and is 1-3 feet taller than the upland strain (Philips Petroleum Company 1955). Because it has superior palatability, the upland strain is preferred for grazing and hay. Switchgrass is nutritious and eaten by all classes of livestock, both as hay and forage. Upland switchgrass is cross-fertilized while the bottomland type is possibly apomictic (USDA 1948). The seeds of many Panicums were used as food in the Southwest, however, their importance as a food source was limited because they drop their seeds quickly after ripening (Doebley 1983). Switchgrass is found frequently on the edges of forests in the pine regions, remnant strips in the prairie regions, and cheniers and spoil banks in the coastal marsh. It ranges throughout the United States and Mexico. "Caniche" is the Acadian French name for switchgrass. It is also called "paille jaune", or yellow straw, a name used to refer to any reed grass (Holmes 1990).


Moist open places, savannas, marshes, waste places.