NATIVE WARM SEASON GRASSES FOR
RIPARIAN HABITAT REHABILITATION

Are there better grasses than tall fescue for wildlife and riparian corridors?
When considering wildlife, without a doubt there are better grasses than tall fescue for riparian corridors. Some of the first grasses that come to mind are the native grasses that historically occurred in those locations. Probably the most recognized and commonly recommended is the native warm season grass, switchgrass. Other, better known native warm season grasses that naturally occurred in riparian corridors are big bluestem, indiangrass, prairie cordgrass, and eastern gamagrass. A cool season native endemic to riparian areas is nodding wildrye or Canada wildrye. Other cool season grasses, preferable to fescue are orchardgrass, red top and timothy.

What are the applications of these grasses?

Switchgrass

As mentioned, switchgrass is probably the most recognized and widely recommended native warm season grass for riparian or wet areas. Switchgrass is well adapted to lowland applications. It withstands a reasonable amount of inundation and can generally survive extended periods of flooding. Switchgrass has been documented to survive complete inundation for up to two weeks during the growing season. Short duration high water events appear to have no effect on switchgrass. Switchgrass will grow in tight, poorly drained soils but establishment is slower than in well drained soils.

Switchgrass seed is readily available through commercial vendors. Switchgrass seed is a small hard seed easily broadcast or drilled using a wheat drill or legume box on conventional grass seeders. There are numerous varieties available. Cave-In-Rock typically exhibits high dormancy. If available, request year old Cave-In-Rock seed. If year old seed is not available, cold, moist stratification will improve initial germination and emergence. Blackwell is often chosen as an alternative to Cave-In-Rock due to its lower dormancy.

Big Bluestem

Big bluestem is not commonly thought of in association with lowland or riparian areas. However, historically large expanses of big bluestem occupied bottomlands throughout the Midwest. J.E. Weaver, in his book North American Prairie, described, "...big bluestem is the most important dominant of grasslands which occupy the broad lowland valleys of Lake Winnipeg and the Red River of the Dakotas, the Missouri, the Platte and Arkansas, and other great drainages as well as the lowlands along their thousands of tributaries throughout the area of true prairie." Big bluestem is perhaps better adapted to well drained, well aerated soils than switchgrass. Big bluestem can withstand periodic flooding provided the soils are well drained. It can survive short periods of inundation, like those associated with flash flooding.

Big bluestem seed is available through commercial vendors. The seed is a fluffy or chaffy and will not flow through conventional drills or broadcast equipment. It can be broadcast when a carrier is used such as wheat, oats, fertilizer or lime. A rangeland drill is recommended. Debearded or brushed seed is available from some suppliers and will flow through some conventional equipment. Two major varieties are available, Kaw and Rountree. Seasonal shortages of either variety may occur. Though Rountree is best adapted east of the Mississippi, Kaw will do fine if Rountree is not available. If both varieties are in short supply, native big bluestem seed is usually available.

Indiangrass

Indiangrass is typically thought of as an upland grass, but naturally occurs in many lowland situations. The fact of the matter is, Weaver documented in lowland prairies which were occasionally flooded or repeatedly burned, indiangrass greatly increased in abundance. Indiangrass is more tolerant of "wet feet" than big bluestem, therefore more applicable to clayey lowland soils. Indiangrass survives flooding and inundation similar to big bluestem.

Indiangrass seed is available through commercial vendors. The seed is a fluffy or chaffy seed and will not flow through conventional drills or broadcast equipment. It can be broadcast when a carrier is used such as wheat, oats, fertilizer or lime. A rangeland drill is recommended. Debearded or brushed seed is available from some suppliers and will flow through some conventional equipment. Two major varieties are available, Osage and Rumsey. Seasonal shortages of either variety may occur. Though Rumsey is best adapted east of the Mississippi, Osage will do fine if Rumsey is not available. If both varieties are in short supply, native indiangrass seed is usually available. Rumsey is best suited for soils with fragipans.

Prairie Cordgrass

Prairie cordgrass is probably the definitive riparian/lowland grass. Also known as sloughgrass, cordgrass occupies the transition zone between moist soil and dry land. Hundreds of square miles of primary bottomlands were dominated by this grass. On the wet side of this grass community were the true wetland plants, sedges, rushes and other moist soil plants. Cordgrass can survive extended periods of inundation, depending on the season.

Cordgrass seed is extremely hard to find in any quantity. Seed prices are equally high. There has been limited success establishing cordgrass from seed on a large scale basis. The most common way of establishing cordgrass is by plugging or sprigging. Both methods have proven successful, however they are labor intensive and expensive.

Eastern Gamagrass

Eastern gamagrass naturally occurs in the narrow transition zone between the cordgrass community and the switchgrass community. Though eastern gamagrass is adapted to lowland/riparian situations, commercial seed sources today are from upland genotypes. Longevity and adaptability of the plants is questionable.

Eastern gamagrass seed is commercially available. Eastern gamagrass seed is similar in size to a soybean or popcorn kernel. The seed is typically planted with a corn planter. Though there are several sources for gamagrass seed there are three major producers. Pete, Iuka and Shepard's PMK-24 are the major varieties. Best results are obtained by planting stratified seed. Shepard's PMK-24 is only sold as stratified seed. Iuka has been selected for superior germination and does not require stratification. Shepard's PMK-24 or Iuka are recommended.

Canada Wildrye

Canada wildrye is a native cool season perennial natural to lower areas. Wildrye, in natural communities, often occurred with switchgrass. Canada wildrye is a short lived perennial.

Seed for Canada wildrye is available commercially, though in limited supplies and high priced. Canada wildrye seed has long, projecting awns and will not flow. It must be either hand sown or planted with a mixture of other seeds, using a rangeland drill.

Orchardgrass

Orchardgrass is an introduced cool season perennial. It is a bunch grass, therefore more desirable for wildlife than sod formers. Orchardgrass is shade tolerant and does well with legume mixtures, such as red clover, ladino clover or Kobe or Korean lespedeza. Orchardgrass seed is commercially available and can be planted with conventional grass drills or broadcast.

Redtop

Redtop is an introduced cool season perennial. It is classed as a wet meadow grass. Redtop is well adapted to wet sites and poorly drained soils. It also has a high tolerance for acid conditions, with a lower pH limit of 4.0 to 4.5.

Redtop seed is readily available through commercial seed sources. Redtop seed is extremely small. Seeding rates should be kept low, 1 to 4 lbs. per acre, depending on application. Seeding can be done by broadcast or drilling, using the legume box.

Timothy

Timothy is an introduced perennial cool season grass. It is well adapted to cool humid climates. Timothy does better with legume mixtures. Timothy is partially shade tolerant.

Timothy seed is readily available through commercial sources. Timothy seed is extremely small. Seeding rates should not exceed 1 to 4 pounds per acre, depending upon application. Seeding can be done by broadcast or drilling, using the legume box.

Orchardgrass, redtop and timothy are commonly used in a mixture. All species are relatively short lived (3 to 5 years) unless planted with legumes or fertilized annually or biennially.

What are the recommended methods of establishment? Establishment of the cool season grasses is by conventional methods familiar to all resource professionals and farmers. Switchgrass, because of it's hard seed can be planted using these methods as well. Particular attention should be given to planting depth, however. Seed should be between 1/4 and 1/2 inch deep and into a firm, fine textured seedbed.

There are a number of establishment methods available for native warm season grasses and most all can be successful. Native warm season grasses can be broadcast, with special considerations, drilled into an prepared seedbed or no-till drilled into crop stubble or sod. Experience has proved the most consistently successful method for establishing native warm season grasses is by drilling with a rangeland drill by either no-till or into a prepared seedbed.

Broadcasting

Broadcasting the chaffy native warm season grasses, big bluestem, indiangrass, little bluestem and sideoats grama require the use of a carrier such as wheat, oats, lime or fertilizer. About a bushel of wheat or oats per acre is necessary for the chaffy seed to flow. Don't use more than that though because of unwanted competition. Mix with lime per soil test and broadcast. When mixed with fertilizer, the most common carrier is potash. About 100 pounds per acre works best. Lime and/or fertilizer and your seed mixture can be spread with an air seeder found at many farmers cooperatives. If using a conventional broadcaster, i.e. an end gate seeder, PTO seeder or lime truck, remember the light fluffy native grass seeds don't travel as far as the carrier, therefore it is necessary to overlap to get good coverage. Broadcast applications require 25% more seed.

Drilling

Conventional Seedbed

Prepare a seedbed as you would for planting alfalfa, a firm, fine textured seedbed is preferred. Plant the native grasses using a rangeland drill. Particular attention should be given to the planting depth. As mentioned before 1/4 to 1/2 inch deep is ideal. Plant slower with a rangeland drill that conventional drills. Seed placement is affected by speed. Typically, planting too fast results in poor seed-soil contact and many times not enough seed in the ground.

No-till, crop stubble or cover crop If there is any actively growing vegetation, spray with Roundup to kill existing vegetation. No-till into killed seedbed. If a flush of weeds comes on after planting and before emergence of the native grasses, Roundup can be used again. If the native grasses have emerged, Plateau can be used on labeled grasses. Severe injury will result to switchgrass, though it will not be killed.

No-till, sod

Spray the sod with Roundup to kill the existing vegetation. Proceed as listed above. Plateau can also be used. It is particularly effective in fescue sod, provided it is sprayed before the fescue enters it's reproductive phase. It is most effective when fescue is between 4 and 8 inches tall.

What maintenance or management is needed for the grasses mentioned?

If weeds are a competitive problem during the establishment of the native grasses, regular mowing through the summer, above any new seedlings, will help with the establishment. The use of Plateau as a post emergence is recommended for labeled grasses to aid in establishment and can be used in lieu of mowing.

Once established the native grasses should be burned every 3 to 5 years to maintain their vigor. Haying or grazing, if allowed, can also be done.

How does the cost of establishment of native grasses compare to fescue?

It is difficult to give an accurate comparison. There are a number of variables to be considered. Planting rate, seed mixture, fertility and pH, planting method, management and maintenance all affect the end cost. The following price comparisons do not include seedbed preparation, planting cost or management/maintence costs. Herbicide costs will also need to be considered if applicable.

Are there other considerations?

Are the alternatives listed superior to fescue for erosion control? If solely considering erosion control, probably not. There is no doubt that switchgrass is more flood tolerant than fescue. There is no doubt that native warm season grasses are better wildlife habitat than fescue. There is no doubt that maintenance is no more or less laborious than with fescue. Additionally, and an important consideration in agricultural areas, switchgrass and big bluestem are tolerant to many agricultural chemicals during their establishment period and indiangrass, once established, is tolerant as well.

When looking at the overall picture and the long term benefits, native warm season grasses are better suited for riparian/lowland areas than fescue.