Muhlenbergia rigens, commonly known as deergrass, is a warm season perennial bunchgrass found in sandy or well drained soils below 7000’ in elevation. The plant is characterized by dense, tufted basal foliage consisting of narrow pointed leaves that reach lengths of about 3’ and range in color from light silver-green to purple. The spike-like culms are less than ½” wide and 3 to 4 feet in length. During bloom, the numerous flowered panicles often reach heights of 5’ and terminate in a single awnless floret with a 3-nerved lemma. Deergrass is characteristic of tallgrass prairie of much of the Western United States.
DistributionDeergrass’s native range extends north into Shasta County in California and south into New Mexico, Texas and Mexico. There it inhabits a wide range of ecotypes including grassland, riparian, chaparral, mixed conifer, and oak woodland communities. Deergrass can grow in areas with periodic flooding, but cannot tolerate standing water and poorly drained soils. It is also shade-intolerant and requires full sun for proper growth.
Establishment & ManagementDeergrass can be established in late spring and early summer by broadcast seeding with irrigation. For best results, 50 seeds per square foot should be planted then lightly incorporated just below the soil surface with a culti-packer. Estiblishment is most successful when steps are taken to mitigate weed growth. Burning, discing and a reduced fertilization schemes to reduce the weed seedbank are recommended (4). Container planting is a highly effective way of establishing deergrass. The seed can be sown in flats in May and transplanted in the fall of the same year. Stand preparation should be the same as when broadcast seeded. During transplant, plants should be spaced with a minimum of 2’ between plants(4). After establishment little management is required. Irrigation is unnecessary in normal rainfall years and fertilization is not recommended as it may increase weed competition. Burning or mowing can be used every few years to reduce accumulated dead matter.
UsesDeergrass is common forage for a variety of animal species, namely deer, cattle and horses. It has also been used for erosion prevention and streambank stabilization because of extensive root systems. Restoration efforts currently use deergrass to displace exotic invasive annuals that dominate current grassland ecosystems as well as remediate overtilled and eroded agricultural land where they anchor loose soils and and return lost organic matter. Phytoremediative studies have also been conducted to test deergrass’s ability to remove chemicals from agricultural runoff. Deergrass’s dense stands and extensive roots act as a biofilter effective for herbicide, pesticide and particulate removal and breakdown. Because deergrass uses C4 carbon fixation, it gains an advantage in conditions of drought and high temperature. This characteristic, along with its attractiveness, has gained the plant recent attention as an ornamental in xeriscapes in yards and parks. Studies have also demonstrated a high tolerance to salt suggesting possible irrigation using low quality reclaimed waste-water sources at very low cost (2).
WildlifeDeergrass is a cover for mule deer during fawning periods and studies have equated reduced deer populations with overgrazed deergrass stands in and near cattle pasture (1). Young shoots and leaves are grazed by deer, horses and cattle. The tall grass is an overwintering host for many species of Lepidoptera and ladybug, which along with deergrass seed, provides food for many different bird species.
HistoryDeergrass was important to many Native American tribes who used its long seedstalks as the principal material in coiled baskets. Deergrass underwent an early form of cultivation by many California tribes who regularly burned areas to maintain stands of deergrass, and induce the production of long strait stalks for use in basketry. Each baskets required over 3000 stalks, driving the need for cultivation (3). It is believed that much of deergrass’s distribution is due to intervention by Native Americans.
References1. Bowyer, RT. Bleich, VC. Effects of cattle grazing on selected habitats of southern mule deer. California Fish and Game. 70:4(1984)240-247
2. Hunter, KAM, Wu, L. Morphological and Physiological Response of Five Californian Native Grass Species to Moderate Salt Spray: Implications for Landscape Irrigation with Reclaimed Water. Journal of Plant Nutrition. 28(2005)247-270
3. Jordan, TA. Ecological and Cultural Contributions of Controlled Fire Use by Native Californians: A Survey of Literature. American Indian Culture and Research Journal. 27:1(2003) 77-90
4. USDANRCS.PLANTS Profile for Muhlenbergia rigens (deergrass). United States Department of Agriculture, Natural Resources Conservation Service. Retrieved on 2008-05-25