Native Grasses, Sedges and Rushes for the Home Landscape

ThisMGNV - Sustainable Landscaping Logo class explains how native grasses, sedges and rushes can add structure and beauty to your garden all year long. Explore the landscape uses for native grasses and sedges, learn how to maintain them, and appreciate the important ways that these plants support wildlife.

Online class offered by Extension Master Gardeners.

Speaker: Extension Master Gardener Elaine Mills who researches and writes many of the resources for  Tried and True Native Plant Selections for the Mid-Atlantic.
Zoom session, recorded August 22, 2020

Video | Plant List | Chat Addendum | Recommended Resources


Video of Presentation

 


NATIVE GRASSES, SEDGES, and RUSHES for the HOME GARDEN

Locally Native Sedges

Locally Native Rush

      • Common/Soft Rush (Juncus effusus)

Locally Native Grasses

Cool Season Grasses

Warm Season Grasses

Additional Native Grasses

        • Prairie Dropseed (Sporobolus heterolepis)
        • Buffalo Grass (Bouteloua dactyloides)


Addendum: Additional Details and Answers to Chat Questions

The native plants described during the main portion of the presentation are native to Arlington County and the City of Alexandria in Northern Virginia, and most of them are also indigenous to the Mid-Atlantic.

  • Viewers from other areas of Virginia will want to look for regional native plant guides. Links to free PDF versions of these guides can be found on the website for the Virginia Native Society at https://vnps.org/virginia-native-plant-guides/
  • Viewers watching from other states may wish to consult county-level maps at https://plants.sc.egov.usda.gov/java/ to confirm the presence of the plants in their regions. Local Extension offices should also be able to provide information on locally native species.

Questions were raised about the unwanted spread of some of the plants discussed. As I pointed out, none of the grasses or sedges in the talk are considered invasive. The term “invasive” is reserved for non-native plants which are introduced into an ecosystem and that spread uncontrollably and cause harm to the environment. (Presidential Executive Order 13112, February 1999).

River Oats/Northern Sea Oats (Chasmanthium latifolium), one of the cool-season grasses, is the only plant I consider aggressive as it can spread by both self-seeding and rhizomes. While Bottlebrush Grass (Elymus hystrix), another cool-season grass, can spread through self-seeding, it’s roots are short and much less tenacious, and I find it easy to pull if it appears outside the areas where I would like it to grow. The sedges generally spread within a limited area via rhizomes, and I find them equally easy to control.

The two sedge species I mentioned during the presentation as replacements for invasive Liriope were Appalachian Sedge (Carex appalachica), which has wide, dense tufts of delicate, grass-like foliage, and Plaintain-leaved Sedge (Carex plantaginea), which has wide, strap-like leaves and measures around 18” across.

To learn about other native plants that can replace invasive ground covers, plan to attend the online public education class on “Native Ground Covers for Sun and Shade” (scheduled for September 25) or watch the recording when it is uploaded to the mgnv.org website at the end of September.

I regret the omission of Path Rush (Juncus tenuis), also known as Slender or Poverty Rush, from my list of recommended plants. I had not seen it in local gardens and have not had personal experience growing it. This cool-season plant is native throughout the United States. It is considerably shorter than Soft Rush at 4-12” tall and has dense clumps of cylindrical stems. Typical growing conditions are full sun to light shade in moist to wet soil. It does well in heavy clay soil and tolerates drought, flooding, moderate salinity, and gets its common name because it can handle compacted soil and a moderate amount of foot traffic.

Poverty Oatgrass (Danthonia spicata) was mentioned by several listeners as a grass species that might tolerate minor foot traffic. It is a clump-forming cool-season grass with twisted, wiry, tufted foliage. It prefers full sun to light shade, dry conditions, and sterile, rocky soil, and doesn’t tolerate competition from taller ground vegetation. Some online sites propose it as a substitute for turf grass, and state of Maryland is studying its possible use as a roadside grass.

Regarding moisture tolerance of Buffalo Grass (Buchloe dactyloides), the grass species that is currently in use as a turf replacement, my further research indicates that it would not do well in moist to wet conditions. The plants are intolerant of lots of moisture and generally do not perform well in areas with high rainfall.

A question was raised about the salt tolerance of Gray’s Sedge (Carex grayi), which I described as tolerant of seasonal flooding. My research indicates that it is moderately tolerant of salt. Our agent lists these species as tolerant of occasional inundation by a tidal creek: Bouteloua curtipendula, Bouteloua gracilis, Deschampsia cespitosa, Sporobolus heterolepis, Eragrostis spectabilis, and Schizachyrium scoparium. Several online sources describe these additional native species as tolerant of salt (either in coastal environments or along roadsides): River Oats (Chasmanthium latifolium), Soft Rush (Juncus effusus), Muhly Grass (Muhlenbergia capillaris), Switchgrass (Panicum virgatum), and Indian Grass (Sorghastrum nutans). In the talk, I described Purpletop (Tridens flavus) as being salt-tolerant.

In response to a chat question regarding grasses for erosion on slopes, I would suggest Little Bluestem (Schizachyrium scoparium), Indian Grass (Sorghastrum nutans), or Switchgrass (Panicum virgatum). I have seen Switchgrass used extensively on the sloping outside edges of rain gardens and have photographed the other two species on sizeable meadow slopes.

In response to a chat question on grasses for pond edges, I would suggest River Oats (Chasmanthium latifolium) for shadier locations, noting the possibility of its aggressive spread [The spreading rhizomes may be just what you want!], or Switchgrass (Panicum virgatum), which has very deep roots, in sunnier locations.

One participant inquired about variations in color of Little Bluestem (Schizachyrium scoparium). Some of that may be attributable to genetic variation within the straight species. Some breeders have selected for certain colors in named cultivars. For example, ‘Jazz’ has silvery blue foliage that turns mauve purple in the fall; ‘Prairie Blues’ has blue-gray foliage that turns red-orange in the fall.

Another participant asked about ‘White Cloud.’ That is a cultivar of Muhly Grass (Muhlenbergia capillaris) with which I was previously unfamiliar. It has the same fine-textured foliage, but its showy seed heads are white. It apparently has a more upright shape, grows a bit taller, and blooms shortly after Pink Muhly Grass. It can be grown in Zones 7 to 10, and its care is the same as for the straight species.

One participant asked about starting plants from seed or plugs. I have personally always purchased small plants from native nurseries. Plugs would be another option for starting to cover large areas in an economical manner, if you’re willing to wait for them to fill it and spread. I gather it would be difficult to start many of these plants from seed in the home garden. 

Someone inquired whether early spring trimming of grasses might disturb bees and other insects that use them as larval hosts. Concern for native bees overwintering in the stems of grasses would only be an issue for the more robust grasses with larger circumference stems, such as Indian Grass and Switchgrass. One solution would be to cut the bottom of the stems to 4-6” high and to retain the upper part of the plant and place it upright in a holder, such as a tomato cage, until the season has advanced. Or you could carefully lay the stems down horizontally in an out-of-the-way garden location. The caterpillars of butterflies, skippers, and moths that would be using grass plants or sedges as larval hosts wouldn’t be feeding on them until the plants put out new green growth a little later in the season.

I did not mention plant care of rushes. The foliage of Juncus effusus is generally described as evergreen, and it retains its color all year long in warm winter climates. In cold areas, it turns yellow in the fall before browning up for the winter. In the early spring, any dead foliage and old flowering stems can be removed. This plant can be propagated by division from mid-spring to early summer.

A question was posed about native species to interplant with sedges. Some that I mentioned in the talk were shade-loving perennials, such as Blue-eyed Grass, Wild Geranium, Marginal Wood Fern, Alumroot, Wild Ginger, Foamflower, Dwarf Crested Iris, and Eastern Columbine.

 Someone inquired about Nutsedge (Cyperus rotundus). This is a non-native species of sedge with an original range in Africa, southern and central Europe, and southern Asia. It is a tenacious, aggressive weed in this country, especially in lawns. Our agent commented: “There are selective herbicides that can control nut sedges in turf grass and planting beds. It WILL however also kill off desirable sedges.”

In response to a question about the use of landscape cloth to control weeds, I would say that information I have received from a local soil scientist advises against it. He suggests that this layer interferes with the normal flow of water and recommends using mulch instead.

Other locally native species recommended by participants:

    • Eastern Narrow-leaved Sedge (Carex amphibola)
    • Virginia Wild Rye (Elymus virginicus)
    • Common Wood Reedgrass (Cinna arundaceae).

 


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