ESTABLISHING NATIVE WARM SEASON GRASSES

Native grasslands are diverse communities that are dominated by a group of plants called graminoids (grasses and grass-like plants in the families Poaceae and Cypereaceae) with a significant component of broad-leaf herbaceous plants (forbs or wildflowers) and less than 10% woody cover. Most native grassland communities in the eastern United States are perennial in nature. An early study by Hubbard (1934) found that 28 tribes of grasses dominate the grassland community on a global basis. In 1950 (Hartley) updated that information and summarized it saying that six tribes dominate including the panic grasses (Paniceae 24.7%), fescues (Festuceae 16.5%), bluestems (Andropogoneae 11.9%), wheat-grasses (Agrosteae 8.2%), love-grasses (Eragrosteae 8.1%), and wild oats (Aveneae 6.3%). The 22 remaining grass tribes, on a global basis, account for 24.3% of the plant community.

A variety of factors, including climate, soils, latitude, longitude, and disturbance history dictate which particular grass species are likely to be found in any native grassland. For example, the percentage of C3 grasses (cool-season) increases at more northern latitudes with a concomitant reduction in C4 grasses (warm-season). The reverse is also true in southern latitudes because the warm-season grasses (bluestems, love-grasses) are adapted to inhabiting open, dry, and hot habitats and are more efficient at conserving water. They typically begin growing when the soil temperatures reach 55 F and in Kentucky this is generally in late April. Their peak growth and production occurs in June, July, and August depending upon species. For example, switchgrass and eastern gamagrass mature in June, big bluestem matures in July, and Indiangrass matures in August. The cool-season grasses (fescues, wheat-grasses) typically begin growing when soil temps are at freezing 32 F and are actively growing in early spring and fall. They are typically dormant during the hot, dry summer months when the native warm-season grasses NWSG are actively growing.

Kentucky had both cool-season and warm-season dominated grassland habitats prior to European settlement. The bluegrass woodlands and savannas of Central Kentucky were primarily dominated by cool-season grasses, particularly the wild ryes (Elymus virginicus, E. villosus, and E. MacGregorii) and cane (Arundinaria gigantea). The grasslands that occurred in the "barrens" region of the Mississippian Plateau are dominated by NWSG that include little bluestem (Schizachyrium scoparium), and Indian-grass (Sorghastrum nutans) with site variation. Historically, you would likely encounter Eastern gamagrass (Tripsacum dactyloides), big bluestem, and switchgrass (Panicum virgatum) on wetter sites and on more shallow sites you would like find tall dropseed (Sporobolus asper), side-oats grama (Bouteloua curtipendula), broomsedge, split-beard, and Elliotts' broomsedge (Andropogon virginicus, ternarius, and gyrans, respectively).

Globally, grasslands are one of the most threatened terrestrial plant communities. The U.S. Geologic Survey estimates less than three percent of the 81 million hectares of original tall grass prairie in North America remain intact. Furthermore, they estimated an overall decline of 79% of all grassland types in North America with the mixed grass and short grass prairies declining by 64 and 66% respectively. Prior to European settlement there were more than 3 million acres of deep soil grasslands in Kentucky. Today less than several thousand acres remain and 64% of the rare communities listed by the Nature Conservancy in Kentucky are grass dominated habitats.

Most native grassland losses are attributed to agricultural conversion to farmland or domestic pastures. Furthermore, the losses produce small isolated fragments that then become susceptible to invasion by exotic plants and these invasive weeds are a major issue in maintaining, rehabilitating, and restoring native plant communities. Consequently, there has been a tremendous interest in re-creating or restoring native grassland habitat. The remainder of the information provided here will guide you into decisions about rehabilitating or creating native grassland habitat based upon more than a decade of research information generated by students in my lab at the University of Kentucky. A summary of our research can be found at the following link in a paper that was published by the Weed Science Society of America in the journal Weed Technology.

RELEASING OR REHABILITATING NATIVE STANDS

The initial question you have to ask is, "Do I need to start from scratch? Or can I simply renovate an existing field of broomsedge or other natural stand of NWSG?" If you have a mixture of about 50% tall fescue and 50% NWSG then I would recommend simply renovating the existing stand with herbicides if you have no intentions of using the grass for grazing or forage. If you do want to use it for agronomic purposes then you will most definitely want to kill everything and start over. If you want the field for wildlife habitat or other purposes you can use a selective herbicide and remove the fescue from the existing sward of grass. Our research information indicates you have three options: 1) apply 12 oz/acre imazapic (Plateau®) with 1 quart methylated seed oil (or other non-ionic surfactant) per acre using a 20 gallon/acre spray rate, 2) apply 2 oz/acre sulfosulfuron (Outrider®) with 1 quart non-ionic surfactant per acre using a 20 gallon/acre spray rate, or 3) apply 12 oz/acre clethodim (Select®) with 1 quart non-ionic surfactant using a 20 gallon/acre spray rate in mid-April (see PowerPoint presentation for data and more information). Using any of these methods will result in significant fescue reduction and will leave most of the native species intact.

ESTABLISHING NWSG

There is much information and misinformation about establishing NWSG and native grasslands that it can be confusing at times to understand what to do and how to do it. While there is no cook-book approach to managing this issue, what is provided here is research based information and if followed carefully will yield excellent results. Attention to detail is critical for establishing NWSG and you should do your homework before beginning the process because failures tend to be quite expensive. Consequently, some over-riding themes that are important are stressed here:
1. Purchase high quality seed. Be sure to take a handful of seed from each bag and send it to the University of Kentucky Regulatory Services and have it tested for quality.
2. Use local genotype seed if possible and available.
3. Match the grass species used with appropriate site conditions.
4. If your goal is wildlife habitat, Do Not add more than ¼ to ½ lb PLS/acre switchgrass. If possible, eliminate its use altogether.
5. Diversify your seeding (both with grasses and forbs) as much as possible because it is extremely difficult to put additional species into the grassland after it has had several growing seasons.
6. No-till conversion of tame pasture or idle grassland is generally more successful than tilling the soil and seeding into a newly created seedbed.
7. It is critical that as much of the existing vegetation as possible be killed prior to seeding NWSG.
8. Weed control during the establishment phase is absolutely critical.
9. Pay attention to how the drill is performing. Get off the tractor and check to make sure seed is dropping from each tube and that it is not seeded any deeper than ¼". This is also critical.
10. In Kentucky and much of the mid-south region, seeding in the spring is preferable to dormant or fall plantings.
11. Patience is definitely a virtue.

Purchase and use high quality seed. NWSG and native wildflower or forb seed can be expensive. In recent times many vendors have entered the NWSG seed business and seed availability, while once a concern, is no longer a valid issue. There is plenty of seed in the market. However, seed quality can vary tremendously and I have seen NWSG plantings where everything has been done appropriately only to find the seeding has failed because poor quality seed was used in the initial planting. In general, NWSG cultivars will establish better in the short-term. When developing a seed mixture for the project the best method is to purchase each type of grass and forb (wildflower) seed separately and create your own mixture. Furthermore, it is absolutely essential that you take a handful of seed from each bag you receive from the supplier and send it to the University of Kentucky Regulatory Services and have it tested for purity, germination, weed seeds, etc. Once you get the test results back, if there are discrepancies between the supplier and UK's test you should contact the vendor and UK and resolve the discrepancy. There is tremendous variability in the quality of NWSG seed and you deserve to get the quality of seed that you have paid for. As the old saying goes, you get what you pay for and if you order the cheapest grass seed available, you are likely to get the worst in seed quality.

Use local genotype seed if possible. There is tremendous interest in restoring or re-creating native grasslands and if that is a conservation goal, you must use local genotype seed. However, if you are interested in other types of plantings, such as for hay or forage, you may want to use an established cultivar. At this time the only local genotype material available in quantity for Kentucky is Roundstone Seed located in Hart County. Dropseed Nursery has small amounts of local genotype seed and plants available for Kentucky. Suggested cultivars of the NWSG recommended for this region include 'Roundtree', 'Kaw', or 'Oz-70' big bluestem; 'Aldous' little bluestem; 'Newberry', 'Osage' or 'Rumsey' Indiangrass; 'Cave-in-Rock', 'Kanlow', 'Durham', and 'Blackwell' switchgrass; 'Highlander', 'Pete', and 'Iuka' Eastern gamagrass; and 'El Reno' and 'Trailway' side-oats grama.

Match the grass species to the site selection. Another common mistake many people make when trying to establish NWSG is planting species that are not adapted to the appropriate habitat. For instance, while switchgrass will grow in uplands, in nature it grows in deeper, wetter soils. The following are general recommendations for grass species by habitat type. Grasses adapted to deep, well-drained to occasionally wet soils would include switchgrass, eastern gamagrass, big bluestem and Indiangrass. Grasses adapted to upland soils that are moderately deep and well-drained would include little bluestem, big bluestem, and Indiangrass. Grasses adapted to upland soils that are thinner would include side-oats grama, little bluestem, tall dropseed, and northern dropseed. Grasses for poor, infertile, upland soils would include the above species plus broomsedge, Elliott's broomsedge and split-beard broomsedge. Some of the early NWSG plantings focused on using switchgrass and from a wildlife standpoint, this grass doesn't provide the quality habitat that big and little bluestem and Indiangrass can provide. Furthermore, it can become quite aggressive and get too thick quickly inhibiting wildlife movement. Consequently, I usually never recommend more than ¼ to ½ lb./acre switchgrass in any wildlife planting.

Attempt to diversify your plantings as much as possible because it is extremely difficult to add species once a sward has been established and the grasses dominate the plant community. Pure stands of grass, unless your objective is to hay or graze the field, does not provide quality wildlife habitat. The more legumes and forbs added in the mix, the better the quality of the habitat. If you want a diverse prairie re-creation you should strive to get a mixture of 60% grass and 40% forbs (wildflowers). Native forbs (wildflowers) also have general habitat requirements and the selection of species will depend on a variety of factors including your budget, seed availability, etc. Because the list of forbs is lengthy, you should talk with a native plant nurseryman, botanist, or other specialist to determine site specific wildflowers to add to the mixture. Remember, more is better.

Our experience has found that the most successful NWSG plantings are created by drilling directly into dead sod. The most difficult situation to establish these grasses is going into previously cropped agricultural lands. While we have not done research to understand why no-till plantings are more successful, I suspect it has to do with reduced weed competition, retaining soil moisture for better seedling establishment, and the use of herbicides in previously cropped fields that have suppressed weeds which are released once you quit farming the site. If you are going into previously cropped agricultural lands keep in mind that if wheat was planted just prior to seeding you should not follow it with NWSG because wheat is allelopathic and will greatly slow the establishment of the grasses. In order for no-till seeding to be successful you must use a good no-till drill. While there are many no-till manufacturer's, we have had the best success using Truax drills . Drill availability is one concern when establishing NWSG and you should contact the KDFWR and click on private lands wildlife biologist to obtain information about your biologist. Contact them for using a no-till drill. Your local county Conservation District or seed supply store may also have a drill for loan or rent.

One of the critical steps in no-till NWSG establishment is to control the existing vegetation as completely as possible. This will involve the use of herbicides. There are multiple options to accomplish this task and depending on what types of vegetation exist in the field to be converted may dictate which herbicide combination works the best for you. In our research we usually prescribe a burn in early to mid-March to remove the residual plant material prior to any herbicide application. If you are able to burn you should only need a single herbicide application in the spring to control the existing vegetation. We generally apply the burn down herbicide in mid-April when the field has greened up and is about 4 to 6" tall. The herbicide options for tall fescue at this point are to use 2 quarts glyphosate, 32 oz Journey® (a mixture of 1 qt glyphosate and 12 oz imazapic), 12oz Plateau® (Imazapic), 2 oz Outrider® (sulfosulfuron), or 12 oz Select® (clethodim) with 1 quart glyphosate per acre along with the appropriate surfactant and adjuvant (ammonium sulfate or 28-0-0 liquid fertilizer). Always read and follow the manufacturer's label when using any herbicide. If you are using Plateau® as your burn down herbicide, you will get the best results if you use methylated seed oil (MSO) as your surfactant (see this web site for excellent information about surfactants: http://www.ext.colostate.edu/pubs/crops/00564.html.

Other exotic grass species are more difficult to kill with a single herbicide application. For example, we have had the best success killing common Bermuda using a combination of 2 quarts glyphosate plus 1 pint arsenal® followed by a 12 oz Plateau® application several weeks after the initial spraying. It appears that 12 oz of Plateau® is necessary because a second study using only 6 oz Plateau® did not provide the same level of control. However, several studies have found that the key to establishing NWSG in Bermuda grass is to control the existing grass as completely as possible. Consequently, you may have to use multiple herbicide applications. Once the Bermuda grass has been controlled you should apply 4 to 6 oz of Plateau®/ acre at seeding for weed control. Another southern species, common Bahiagrass is also difficult to control because it is tolerant (like many other Paspalums) to Plateau® or Arsenal®. Consequently, you may have to use multiple glyphosate applications to kill the existing vegetation.

We are currently exploring herbicides that will kill smooth brome, reed canary grass, and the old world bluestems and as information becomes available, it will be posted on this site.

Proper Planting is a MUST!!!! Far too often NWSG plantings fail because of poor seed quality or poor seeding techniques. It is important that there is good seed-soil contact for appropriate germination and growth. Which ever method of seeding or drill you use, the most important thing is that the seed is no deeper than ¼" in the soil. Any deeper and it will not germinate. It is better to have seed on top of the ground rather than too deep in the furrow. Furthermore, it is important that you calibrate your drill and when drilling actually get off the tractor to make sure you are putting seed in the ground. I have seen far too often where drill tubes get plugged and no seed is actually put in the ground. I recommend you get off the tractor after every round and check the drill tubes.

The preferred season to establish NWSG in Kentucky and the mid-South is spring. We have attempted numerous fall or dormant plantings and they generally fail or do not establish as well as the spring plantings. The best time for seeding in Kentucky is May and early June. However, you can seed up into July if there is sufficient rainfall but it gets risky this time of the year. If you are going to diversify your stands with additional grass species and forbs (wildflowers) that are not tolerant to Plateau® herbicide, we recommend a double seeding. Seed the grasses and Plateau® tolerant wildflowers in the spring and then in late-fall or early winter, seed the additional species into the field. I recommend you run the drill perpendicular to the original spring planting to maximize seed getting into bare ground between grass plants. This method has worked exceptionally well because many of the wildflower seeds need a cold period to germinate and will sprout in the spring. Furthermore, it is extremely difficult to put the wildflowers into the grasses after they have become established by the end of the second growing season.

Patience is definitely a virtue when establishing NWSG. Don't begin to stress over the planting until after the second year. At that time if you do not see signs of significant NWSG and wildflowers you might consider the planting a failure and start over.

The information I have provided here is designed to supplement what is found on other governmental sites for establishing NWSG. Please see the links section below for more detailed information on establishing these grasses.

LINKS (other sites with more information about native warm season grasses)

http://www.conservation.state.mo.us/documents/landown/nwsg.pdf
http://www.utextension.utk.edu/publications/pbfiles/PB1746.pdf
http://www.ca.uky.edu/agc/pubs/agr/agr145/agr145.pdf
http://www.in.gov/dnr/fishwild/hunt/warmgrass.pdf
http://fw.ky.gov/native.asp
http://www.wildlifemanagement.info

RESEARCH PUBLICATIONS (Please email tbarnes@uky.edu for reprints of articles)

T.G. Barnes 2004. Strategies to Convert Exotic Grass Pastures to Tall Grass Prairie communities. Weed Technology 18:1364 - 1370.

Ruffner, M.E. and T. G. Barnes 2004. The efficacy of herbicides for eradicating tall fescue. North American Prairie Conference 18:67-74.

C. Rhoades, T. Barnes, and B. Washburn. 2002. Prescribed fire and herbicide effects on soil processes during barrens restoration. Restoration Ecology 10:656-664.

Washburn, B.E., T.G. Barnes, C.C. Rhoades, and R. Remington. 2002. Using imazapic and prescribed fire to enhance native warm season grasslands in Kentucky, USA. Natural Areas J. 22(1):20-27.

Madison, L.A., T.G. Barnes, J.D. Sole. 2001. Effectiveness of fire, disking, and herbicide application in removing tall fescue dominated fields. Wildlife Society Bulletin 29:706-712.

Washburn B.E. and T.G. Barnes. 2000. Post-Emergence Tall Fescue (Festuca arundinacea) Control at Different Growth Stages with Glyphosate and AC 263,222. Weed Technology 14:223-240.

Washburn, B.E. T. G. Barnes, J.D. Sole. 2000. Improving northern bobwhite habitat by converting tall fescue fields to native warm season grasses. The Wildlife Society Bulletin 28:97-104.

Washburn, B.E. and T.G. Barnes. 1999. Converting Tall Fescue Grasslands to Native Warm-Season Grasses. Eastern Native Grass Symposium 2:331-341.

Washburn, B.E. and T.G. Barnes. 2000. Native Warm-season Grass and Forb Tolerance to Imazapic and 2,4-D. Native Plant Journal 1:61-68.

Washburn, B.E., T.G. Barnes, J.D. Sole, R. Hines. 1999. Eradicating Tall Fescue Using Glyphosate Followed by Cool-season Grass Seedings. Proceedings Southeastern Association of Fish & Wildlife Agencies 53:270-281.

B.E. Washburn, T.G. Barnes, J.D. Sole.1999. No-till Establishment of Native Warm Season Grasses in Tall Fescue Fields. Ecological Restoration 17:40-45.

T.G. Barnes, J.L. Larkin, M.B. Arnett. 1998. Establishing Native Warm Season Grasses on Eastern Kentucky Strip-mines. Proceedings of the American Society of Surface Mine Reclamation 25:615-633.

Madison, L.A., T.G. Barnes, J.D. Sole. 1995. Improving Northern bobwhite brood rearing habitat in tall fescue dominated fields. Proceedings of the Southeastern Association of Fish & Wildlife Agencies 49:525-536.

Barnes, T.G., L.A. Madison, J.D. Sole, M.J. Lacki. 1995. An assessment of tall fescue dominated fields habitat quality for northern bobwhite. Wildlife Society Bulletin 23:231-237.

Side oats grama Flower