Planting grasses (seeds, plugs or plants) is a quick and fairly inexpensive way to establish cover on bare, disturbed ground. Figuring out which species are adapted to your site is worth your time to assure good establishment and to prevent using a species that is inappropriate.
Selecting the most appropriate native grasses for your site can be challenging! Montana has 236 native grass species and numerous non-native species.
Unfortunately some non-native species are aggressive and invasive and these undesirables are often planted by unwitting landowners. It is surprising how many of these are included in grass seed ‘mixes’.
How do we determine if a species is desirable?
Learn to identify grasses in your local area. Identify both native and non-native species present on your site. Examine your site conditions and select species appropriate for that site.
Grass identification can be difficult and usually requires the inflorescence (flower-like structure) of the grass to be present for correct id. Here are a few options for determining what grasses you have on your property:
- use the “Montana Grasses” app
- take a sample to your extension service agent
- find a willing botanist to assist
Chances are you have weedy grasses on your site as well as desirable species. Knowing what species you are dealing with is important. Here are some examples of invasive grasses in Montana according to the Center for Invasive Species and Ecosystem Health:
- cheatgrass (Bromus tectorum),
- smooth brome (Bromus inermus)
- Bermuda grass (Cynodon dactylon)
- quackgrass (Elymus repens)
- orchardgrass (Dactylis glomerata L.)
- reed canary grass (Phalaris arundinacea)
- timothy (Phleum pratense)
- bulbous bluegrass (Poa bulbosa)
- annual bluegrass (Poa annua)
- canada bluegrass (Poa compressa)
- Kentucky bluegrass (Poa pratensis)
Weedy grasses invade and colonize disturbed sites where they freely reproduce and thrive, outcompeting native species. Not only does this devalue land but creates serious eradication challenges when we attempt to restore native grasslands.
Whether or not we can truly restore a native grassland to its former condition is a subject of debate for another day, but leaving sites to be overtaken by weedy species is perhaps one of the most serious ecological issues we currently face.
Once you have identified species present on the property determine tactics for reducing weedy species while increasing native species appropriate for your site. It may be impossible to totally eradicate weeds without serious damage to soil. Tactics for reducing weeds might include hand-pulling, bio-controls or herbicides.
Can native grasses be weedy? Yes, when introduced to different conditions than they normally exist in.
- A drought tolerant native grass may reseed like crazy when introduced to an irrigated site. (e.g. prairie junegrass)
- A rhizomatous (spreads by underground stems) grass (e.g. sweetgrass) may take over an entire area if the soil is moist and comprised of organic matter. In the wild sweetgrass would be restricted by the size of the moist meadow in which it lives. In a garden it could become invasive.
It’s all about ‘right plant, right place.’ It’s an old adage but it’s still true.
Ideally replicating the native grass palette already in place is optimal for the ecosystem, plant health and local fauna. Right plant, right place!
Assess the climactic conditions on your site. Is it sunny, shady, moist, dry, sloped? Keep in mind conditions may have changed due to construction, soil disturbance, compaction, removal of forest canopy and vegetation, etc… and you may be dealing with an altered landscape that may have difficulty supporting species that once grew there.
Next select species appropriate for your site. Match growing conditions. Use a mix of grasses already in the area. Naturalistic plantings include a mix of grass species and forbs (wildflowers and herbaceous plants).
Examples of native grass species in northern Rocky Mountains:
Examples of native grass species in northern Rocky Mountains:
|Achnatherum (Oryzopsis) hymenoides||indian ricegrass||medium||moderate||full||sandy||drought tolerant, short-lived, ornamental|
|Aristida purpurea||purple threeawn||short||moderate||full||sandy||easy to establish, warm season grass
|Bouteloua gracilis||blue grama||short||little||full||sand to silty-loam||drought tolerant, moderate establishment|
|Bromus marginatus (carinatus)||mountain brome||medium||high||full to part sun||silty-loam to clay||short-lived, rapid establishment, keep moist|
|Calamagrostis rubescens||pinegrass||medium||moderate||part to full shade||silty-loam to clay||rhizomatous, understory in coniferous forests|
|Danthonia unispicata||one-spike oatgrass||short||moderate||full to part sun||sand to clay||moderately easy establishment|
|Deschampsia cespitosa||tufted hairgrass||medium||very high||full||silty-loam to clay||very moist sites|
|Elymus canadensis||canada wildrye||tall||moderate||full||sand to silty-loam||rapid establishment, short-lived, moist sites|
|Elymus glaucus||blue wildrye||tall||moderate||full||sand to silty-loam||rapid establishment, short-lived, good for stabilization|
|Elymus lanceolatus aka Agropyron dasystachyum)||thickspike wheatgrass||medium||little||full||sand to clay||rhizomatous, drought tolerant, short-lived
|Elymus (Agropyron, Pascopyrum) smithii||western wheatgrass||medium||moderate||full||silty-loam to clay||drought tolerant, long-lived|
|Elymus trachycaulus aka Agropyron caninum, Agropyron trachycaulum)||slender wheatgrass||tall||high||full||sand to clay||moderate drought tolerance, rapid establishment, short-lived, good high elevation species|
|Festuca campestris||rough fescue||medium||moderate||full to part sun||silty-loam to clay||priries and open woods, does not tolerate trampling|
|Festuca idahoensis||Idaho fescue||short||little||full||silty-loam to clay||slow establishment, moderate drought tolerance
|Hierochloe odorata (Anthoxanthum hirtum)||sweetgrass||medium||very high||full||silty-loam to clay||rhizomatous, wet meadows|
|Hordeum jubatum||foxtail barley||short||little||full||sand to clay||easy to establish, good for disturbed areas, awns problematic for pets|
|Koeleria macrantha, Koeleria cristata||prairie junegrass||short||little||full to part sun||sandy||drought tolerant, early season|
|Leymus cinereus, aka Elymus cinereus||great basin wildrye||tall||little||full||silty-loam to clay||spring moisture followed by dry, slow establishment|
|Phleum alpinum||mountain timothy||short||high||full to part sun||clay||short-lived, prefers poorly drained mountain meadows|
|Poa secunda||Sandberg bluegrass||short||little||full||sand to clay||drought tolerant, early season, slow establishment|
|Pseudoroegneria spicata, aka Agropogon spicatum||bluebunch wheatgrass||medium||moderate||full||silty-loam to clay||drought tolerant, moderate establishment|
|Stipa (Hesperostipa) comata||needle and thread||medium||moderate||full||sand to silty-loam||drought tolerant, long-lived; long awns problematic for pets|
|Stipa nelsonii (Achnatherum) nelsonii||Columbia needlegrass||medium||moderate||full||silty-loam to clay||drought tolerant, moderate establishment
|Stipa (Achnatherum ) occidentalis||western needlegrass||medium||moderate||full to part sun||silty-loam to clay||drought tolerant, long-lived|
|Stipa (Achnatherum) richardsonii||Richardson's needlegrass||medium||moderate||full to part sun||silty-loam to clay||drought tolerant, long-lived, awns problematic for pets|
|Stipa (Nassella) viridula||green needlegrass||medium||moderate||full||silty-loam to clay||drought tolerant, moderate establishment|
Not all species work in all places – right plant, right place! Know what type of site each species needs.
Once you know what species are appropriate for your site and have dealt with weeds, where can you obtain grass seed, plugs or plants?
When you check out seed companies and look for native grass seed you will often find that they offer cultivars of natives – plants selected for desirable characteristics that can be maintained by propagation. This is done through selection, hybridization, and genetic modification but the thing to remember is that a cultivar has a particular trait that it has been replicated through propagation. For example, a grass may be selected for its blue color, or it’s ability to produce lots of seed, or it’s ease of establishment. These traits may or may not be desirable.
A cultivar is designated by a word or several words in quotation marks that follow the botanical name, for example: Pseudoroegneria spicata ‘Secar’ or a list of cultivars following the plant description: Secar, Goldar, Whitmar.
There is ongoing debate over the use of cultivars. My preference is to avoid them. They lack genetic diversity and impact the gene pool in the wild. Their homogeneity tends to look unnatural and there is concern over their value to wildlife that has evolved over time with a genetically diverse population.
On the other hand it may be difficult to locate seeds of native grass species.
One option is to collect your own seed. If you don’t have time to do that, select native species and create your own mixes. Keep in mind you only need small quantities of small seeds and larger quantities of big seeds. Most seed companies will provide the number of live seeds per pound and seeding rates for pure stands.
The Montana State University Extension publication Revegetation Guidelines for Western Montana may be helpful.
Some companies that sell native grass seed:
Let me know if you have another favorite so I can share the info!