Author: John R. Hall III, Extension Agronomist, Turfgrass Management, Virginia Tech
Publication Number 460-127, January 1997
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Tall fescue is a moderately coarse-textured, olive-green turfgrass tolerant of a wide range of management and climatic extremes. It performs best on well-drained soils. It has good drought tolerance and provides moderate to good levels of turfgrass quality with limited maintenance. The new "turf-type" tall fescue varieties are more dense and finer bladed than the traditional K-31 tall fescue and have provided higher turf quality in full sun or light to moderate shade.
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Tall fescue can be established from seed or sod and is well suited for use on lawns, or moderately trafficked athletic fields. It is not particularly tolerant of heavy traffic and does tend to be susceptible to Rhizoctonia Brown Patch in wet, hot summers. When used in areas where moderate to heavy traffic is expected, it is advisable to include 10 percent Kentucky bluegrass in the seed mixture for lateral healing potential.
Kentucky bluegrass is a medium-textured, blue-green turfgrass best suited to well-drained or moderately well-drained soils and moderate to high levels of sunlight. It responds well to high levels of management and does have the potential to provide a higher level of turf quality than tall fescue. In heavily trafficked areas, it does show better persistence than tall fescue.
On newly disturbed mine soils the lack of earthworms, and microbial inactivity, contribute to increased rates of thatch buildup in Kentucky bluegrass. Kentucky bluegrass generally has more insect problems than tall fescue.
The fine texture of Kentucky bluegrass makes coarse grass contaminants such as orchardgrass and tall fescue, which are common on surface mine sites, more objectionable. Most mine operators have used tall fescue in reclamation seedings, therefore the potential for tall fescue contamination of seeded Kentucky bluegrass is high. Selective removal of tall fescue clumps from Kentucky bluegrass stands is possible with a herbicide called chlorsulfuron. Kentucky bluegrass can be established from seed or sod. Sodding minimizes the potential for coarse grass contamination.
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Hybrid bermudagrass selected for cold tolerance has potential for use on surface-mined land. Bermudagrass is a warm-season grass that persists under lower mowing heights than tall fescue and Kentucky bluegrass. It has good drought tolerance and insect and disease resistance and is best suited to athletic field or golf course fairway use at lower elevations in southwest Virginia.
It has good summer and early fall traffic tolerance and mid-summer recuperative potential. Bermudagrass is prone to severe injury if heavily trafficked in early spring or late fall. It lacks shade tolerance and goes dormant, turning brown after the first frost in the fall. It will remain brown from the first hard frost in the fall until late April or early May in southwestern Virginia. Because of this, it is not particularly well suited to home lawn situations. The hybrid bermudagrasses cannot be seeded and are established by planting sod, vegetative sprigs or plugs. Irrigation is necessary to insure successful sod or sprig establishment.
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Zoysiagrass is an olive-green, warm-season grass of fine to medium texture that turns brown with the first hard frost in the fall and turns green in late April. It is an extremely low maintenance grass with good insect and disease resistance.
It can be established from seed, sod, sprigs or plugs. Seed is scarce and expensive and is extremely difficult to successfully germinate. Sprigs or plugs of zoysia are much more readily available. They are generally slow to establish, requiring two to three growing seasons for complete ground cover. Its slow recuperative potential makes it generally undesirable for athletic fields unless they are lightly trafficked. This grass has more shade tolerance but less recuperative potential than bermudagrass. It is most suitable for home lawn use, cemeteries, and low maintenance sites.
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See Figure 2.
Perennial ryegrasses have been evaluated on strip mine soils in southwest Virginia and their long term performance in pure stands has been unacceptable. They are susceptible to Winter Brown Blight, Helminthosporium Leaf Spot and Rhizoctonia Brown Patch disease activity. They are not recommended in pure stands except on heavily trafficked athletic fields where annual reseeding is necessary. On sites where Kentucky bluegrass is the grass of choice, and a potential for erosion exists, they can be beneficially included with bluegrass at 10 to 15% of the Mixture.
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Creeping red and Chewing's fine fescue, are acid, shade and drought tolerant turfgrasses that have been tested in the Powell River Project research. These grasses rapidly developed thatch under all soil amendments tested (Figure 3). This thatch led to turf quality decline in pure stands of these grasses within two to three years. Our research provided 3 lb nitrogen per 1,000 square feet per year to the grasses. This may have aggravated the development of thatch in this species. These grasses are not recommended in pure stands on surface-mined soils at this time. They are best used as companion grasses with Kentucky bluegrass in mixtures containing 85 to 90 percent Kentucky bluegrass and 10 to 15 percent fine fescue.
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Each method of establishment has advantages and disadvantages. Seed is generally cheaper to plant than sod, sprigs or plugs. Seed, sprigs and plugs all require early establishment weed control and variable amounts of time for complete ground cover development. Mature stands of tall fescue and Kentucky bluegrass generally require six to nine months from seed. Sprigged bermudagrass requires 45 to 60 days to provide 100 percent ground cover. However, sprigged stands of bermudagrass should not be considered mature until the end of the second growing season. Zoysiagrass is likely to require two full growing seasons to provide 100 percent ground cover from sprigs and three full growing seasons to provide total cover from plugs planted on 12 inch centers.
Where immediate erosion control or the need for mature turf is a major concern, sodding is certainly the best alternative. Irrigation is a necessity for successful sodding, sprigging and plugging.
If seeding is the method of establishment chosen, either hydraulic seeding or traditional seeding may be used. Hydraulic seeding is ideally suited to situations where the slope of the land is severe. It involves spraying the seed on the soil surface in a water, fertilizer, lime and mulch slurry. It is not conducive to maximum seedling survival since the seed is seldom in complete contact with the soil; however, it is popular on surface-mined land because new rocks are not brought to the surface in the planting process. Traditional seeding methods involve prior incorporation of recommended nutrients and lime into the soil followed by incorporation of the seed into the surface of the soil with mechanical planters or by raking. Traditional seeding, including nutrient incorporation, is much preferred on surface-mined soils because phosphorus and lime incorporation is important to rapid and deep correction of these common deficiencies. However, the rocky nature of surface-mined soils often makes fertilizer incorporation difficult as every tillage procedure tends to bring new rocks to the surface. When soil tests indicate phosphorus and lime requirements are extreme, soil incorporation of the nutrients and lime is beneficial.
An important key to success with all methods of establishment is the purchase of quality plant material. Insist on Virginia Crop Improvement (VCIA) certified seed, sod or sprigs in all instances. VCIA labels insuring certification will be affixed to the seed package or delivered with sod, sprigs or plugs.
Time of establishment can often affect the selection of turfgrass and the method of establishment. Kentucky bluegrass and tall fescue are best established in the fall between August 15 and the end of September. The second best time for establishment of these grasses is in the spring between March 15 and May 1. Bermudagrass and zoysiagrass are most successfully established from May 1 to July 15.
Time delays in construction often necessitate establishment outside the desirable period. In these instances, it may be wise to switch the type of turfgrass or method of establishment to maximize chances for success. For instance, delays necessitating late fall or winter establishment may justify switching from seed to sod of Kentucky bluegrass or tall fescue. Delays necessitating summer establishment may justify switching from Kentucky bluegrass and tall fescue to bermudagrass or zoysiagrass. Delays from early summer to late summer may justify switching from sprigs of bermudagrass or zoysiagrass to sod.
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Special interpretation of tests is required for surface-mined soils, so be certain the lab you choose can interpret the results. Tests for surface-mined soils are available through the Virginia Cooperative Extension offices in each county. The exact amounts of lime, phosphorus and potassium required for establishment will be indicated by the laboratory.
Nitrogen requirements for establishment vary with season and method of establishment as well as type of turfgrass. Warm-season grasses such as bermudagrass and zoysiagrass are normally established in early summer, whereas cool-season grasses such as tall fescue and Kentucky bluegrass are established in spring and fall. If lime, phosphorus and potassium requirements are being met, incorporation of nitrogen at the rates indicated in Table 1 should be adequate.
Table 1. Amounts of soluble nitrogen recommended for turfgrass establishment at various times for cool- season and warm-season turfgrasses on surface mined soils.
| Season | Turfgrass Type1 | Method of Establishment | |||
| Seed | Sod | Sprigs | Plugs | ||
| --- lb N/1,000 sq ft2 --- | |||||
| Fall | Cool-Season | 2.5 | 2.5 | NA3 | NA |
| Spring-Summer | Cool-Season | 1.5 | 1.0 | NA | NA |
| Warm-Season | 2.5 | 2.0 | 2.5 | 2.5 | |
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Table 2. Original soil amendments and recommended application on surface mined soils.
| Material | Volume per 1000 sq. feet | Depth of material before incorporation to 6 to 8 inches |
| Cubic Yards | Inches | |
| Sawdust1, 3 | 3 to 6 | 1 to 2 |
| Composted Sludge2, 3 | 3 to 6 | 1 to 2 |
| Composted Leaves3 | 3 to 6 | 1 to 2 |
| Peat or sphagnum3 | 3 | 1 |
| Rotted Farm Manure2 | 3 | 1 |
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Prior to seeding, rocks, wood and debris larger than 2 inches in diameter should be removed from the site. If any undesirable plant material exists in the area to be planted, it should either be physically removed or controlled with a non-selective herbicide such as glyphosate.
After incorporation of fertilizer, lime and soil amendments and prior to planting of the grass, it is important to make final preparations for planting. Do not plant when the soil is exce ssively wet or dry. The soil should have a blocky, granular structure and not be powdery or contain large clods.
Prior to making the final purchase of materials or contracting to have the work done, measure areas to be planted to be certain material requirements or bids have been properly calculated. In situations where irrigation will be necessary for establishment, confirm irrigation capability so that areas to be planted are not larger than can be adequately irrigated.
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Straw mulches usually come from wheat or oats and may be spread by hand or machine. (See Figure 7.) Normal rates of straw application provide 1.5 to 2 bales of straw per 1000 square feet (1.5 to 2 tons of dry straw per acre). Straw can be windblown and therefore should be tacked down either with wood fiber mulch or with a mulch anchoring tool. A mulch anchoring tool is a tractor drawn, disc-like implement that has a dull, serrated edge that punches the straw into the surface of the soil. The rocky nature of surface-mined soil reduces the effectiveness of these mulch anchoring tools. However, straw mulch can also be anchored with liquid mulch binders such as asphalt. Asphalt is applied at the rate of 10 gallons per 1000 square feet. In residential areas where asphalt may not be desirable, the straw can be secured with chemical binders, pegs and twine or lightweight plastic or paper nets stapled over the straw.
Wood and paper cellulose fiber materials are applied in a water slurry through a hydroseeder. These materials provide adequate mulching in normal seeding situations. (See Figure 8.) However, when seeding where the seedling environment will be hostile due to slope, time of seeding, or soil texture, straw mulch anchored with wood fiber mulch provides the best overall seedling environment. Turf areas to be mowed normally have a slope of 3:1 or less and therefore mulching rates providing either wood fiber mulch alone at 1,000 to 2,000 lbs per acre or a combination of 3000 lbs of straw plus 750 lbs of wood fiber mulch per acre have proven adequate. If straw is used at the above mentioned rates, it will not have to be raked out of the seeding after germination unless it was not uniformly distributed.
Erosion nets and mats are increasingly popular in areas where extreme erosion potential exists. Jute nets are installed either alone or on top of the mulch. Excelsior mats may be used alone or incorporated with seed. In instances where the seed is incorporated in the excelsior mat it is important to be aware of the long term quality potential of the species and varieties in the mat.
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Rolling all newly planted turfgrass areas with a weighted roller at the time of seeding speeds up germination and increases seedling survival. In sodded and plugged areas it removes air pockets between the sod and the soil and improves rooting.
In spring seedings where crabgrass control is desired in association with the seeding, siduron pre-emergence herbicide should be applied immediately after seeding and prior to mulching or irrigating. This material is available in a sprayable wettable powder or dry granular formulations.
Broadleaf weeds in newly seeded turfgrass areas can be most effectively controlled after the second or third mowing using traditional broadleaf herbicides, such as 2,4-D, dichlorprop, mecoprop, Triclopyr, dicamba or combinations of these materials. In all cases where a decision is made to use herbicides, read and closely follow label directions.
Mowing practices during the establishment stages are critical. Begin mowing with a sharp mower when the grass is one-third higher than the mowing height at which you intend to mow. Continue to mow with a frequency which never removes more than one-third of the existing green tissue. Alternate mowing patterns to minimize the negative effect of compaction on the young seedlings. Kentucky bluegrass and tall fescue turf should be maintained at mowing heights between 1.5 to 2.5 inches. Bermudagrass and zoysiagrass can be maintained at mowing heights between 0.75 and 1.5 inches.
Normal maintenance fertilization practices should begin 60 to 90 days after establishment.
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Most newly surface-mined lands are low in microbiological activity and our research indicates extremely high rates of thatch buildup in those species that are thatch-prone. This tendency must be dealt with by either selecting varieties that are not thatch-prone or utilizing establishment, cultivation or management practices that maximize the potential for microbiological activity. The tall fescues and perennial ryegrasses have shown considerably less tendency to produce thatch on surface-mined soils than the Kentucky bluegrasses, creeping red fescues, and the Chewings fescues. Establishment procedures that include organic matter amendment of surface-mined soils generally increase microbiological activity and can be beneficial. Cultivation practices such as core aerification and topdressing can improve thatch decomposition rates. Management programs that include moderate levels of nitrogen, proper mowing frequency, and selective and judicious use of pesticides can minimize potential rates of thatch buildup.
The major considerations in setting up a turfgrass management program on surface-mined soils in southwestern Virginia include:
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Nitrogen fertilization is critical to maintenance of quality turfgrass on surface-mined soils. Cool-season grasses such as tall fescue, Kentucky bluegrass and perennial ryegrass respond best to fertilization in the fall. Bermudagrass and Zoysiagrass are warm-season grasses, and respond best to summer applications of nitrogen. Fertilization programs outlined in Tables 3 and 4 will provide adequate amounts of nitrogen in most years. In years when rainfall is above normal and where surface-mined soils are well drained, utilization of the higher levels of nitrogen would be advisable.
Table 3. Fertilization program for Kentucky bluegrass and tall fescue lawns using water soluble fertilizers.
| Time | Nitrogen (lbs per 1000 sq ft) | Application Priority |
| September | 1 | 2nd |
| October | 1 | 1st |
| November or December | 1 | 3rd |
| May 15 to June 15 | 0 to 0.75 | 4th |
| TOTAL | 3 to 3.75 |
Table 4. Fertilization program for bermudagrass and zoysiagrass lawns.
| Time | Nitrogen (lbs per 1000 sq ft) | Application Priority |
| April | 1 | 1st |
| May | 1 | 2nd |
| July | 1 | 3rd |
| TOTAL | 3 |
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2. Sources of nitrogen - Soluble sources of nitrogen may burn leaf tissue if applied when temperatures are high or there is moisture on the leaf blades. Water the lawn after fertilization to wash particles off the blade. This is particularly important when using urea or ammonium nitrate. Slow release fertilizers containing more than 50 percent water insoluble nitrogen may require slightly higher application rates to get a response equivalent to water soluble materials. Slow release nitrogen sources should be used on sandy soils to reduce the potential for nitrate leaching.
3. Use lower amounts of nitrogen - In heavily shaded areas it may be beneficial to reduce fertilization rates by cutting application rates in half. Reduction in nitrogen levels on cool-season grasses can be effectively achieved by not starting the fertilization program until the leaves have been collected in the fall. Established zoysiagrass lawns require less nitrogen than bermudagrass lawns. As a lawn matures, its nitrogen requirement decreases, therefore, on older lawns use the lower rates or even consider skipping one or two of the applications in some years. If clippings are being returned to the lawn the above recommendations can be reduced by approximately one third.
4. Use more frequent and lower rates of nitrogen - When you are using a water soluble nitrogen source and where soils are sandy, irrigation is extensively used, the growing season is extended, or short term recuperative potential is needed.
5. Late fall applications on cool-season grasses - The November-December application should be made after the last mowing in the fall. It is important that the grass not go into the winter with excessively long foliage.
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Reel mowers provide the highest quality of cut and should be utilized in those situations where the highest quality turf is desired. Rotary mowers are cheaper to purchase and maintain. They have the advantage of providing closer trimming capability and are best suited to rough terrain mowing.
The proper height of cut is important as it has a direct relationship upon the potential to develop a root system. Kentucky bluegrass, tall fescue, perennial ryegrass, the fine fescues and mixtures of these grasses should be mowed between 1.5 and 3.0 inches. Bermudagrass and zoysiagrass is best maintained between 0.75 and 1.5 inch. The higher mowing height in these ranges will produce healthier turfgrass plants with greater root systems and less predisposition to disease. The higher mowing heights are particularly beneficial where the surface is rough and during periods of heat or drought stress.
Frequency of mowing is very important as it has been shown that improper mowing frequency will actually reduce root growth. Proper mowing frequency is determined by the rate of growth. A lawn should be mowed with a frequency that insures that no more than one-third of the existing green tissue is removed at any one time. For instance, if a lawn is being mowed at a 2 inch mowing height, it should be mowed before it reaches 3 inches in height. If lawns are being mowed with the proper mowing frequency, it should not be necessary to collect clippings. If clippings collect in piles on a lawn, they should be raked out to prevent overheating and shading of the grass underneath.
Maintaining a sharp mower is extremely important as it minimizes the damage associated with mowing. When a grass plant is mowed, wound hormones and stored food reserves are mobilized to heal the wound. The more severe the wound, the more of these materials are utilized. These stored food reserves provide the energy for the production of roots, leaf tissue, stolons and rhizomes. Therefore, it is not efficient to waste this energy healing wounds caused by a dull mower.
Clippings should be returned to the lawn since they provide significant nutritional value to the lawn. It is estimated that this management practice will reduce fertilizer requirements on the average lawn by one-third. In addition researchers have noted that returning clippings promotes increased earthworm populations which serve to aerate the soil and reinoculate the thatch with soil, aiding in thatch decomposition.
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Areas needing water will show a blue-green cast associated with the early stages of wilt. Once a turf develops this color, it will require water within 12 hours or it will go into the browning stage. Areas can be tested for water need by forcing a screwdriver into the soil. If it requires a great deal of force to get the screwdriver into the soil it most likely needs water.
It is best to irrigate turfgrasses in the early morning. Late afternoon or early evening irrigation is not advisable as it leaves the foliage wet going into the evening. This condition promotes maximum disease activity and should be avoided. However, when wilt injury is imminent, do not delay irrigation.
Turfgrasses will normally require about 1 to 1.5 inches of water every week that passes without rainfall. Determination of how much water is being applied in irrigation is easily done by placing low profile flat pans in the irrigated area and measuring the depth of the water in them following timed periods of irrigation. The water delivery rate can then be determined in inches of water delivered per hour.
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Lawns newly established on surface-mined land are going to be prone to the development of heavy thatch layers in the first three to five years. This is primarily due to the fact that these soils are inherently low in microbiological and earthworm activity. The addition of organic matter soil amendments during establishment may increase microbiological activity. However, the simplest way to avoid a thatch problem is to utilize turfgrass species that are not prone to thatch development and develop a turf management program that does not promote thatch.
Tall fescue (Figure 9) and perennial ryegrass do not tend to produce heavy thatch. Some varieties of Kentucky bluegrass (Figure 10), creeping red fescue, bermudagrass and zoysiagrass are capable of excessive thatch development under intense management. Developing turf management programs with moderate levels of fertilization, proper mowing practices to include returning clippings to the lawn, and periodic aerification will minimize the rate of thatch buildup. Earthworms have a significant role to play in thatch decomposition and most insecticides and some fungicides have a deleterious effect on earthworm populations. Therefore, judicious use of these materials is advised in situations where thatch buildup is a concern. Insecticides containing Carbaryl, ethoprop and bendiocarb are particularly harmful to earthworm populations and should be judiciously applied.
Core aerification is the practice of removing plugs of soil from the turf. It is difficult to effectively accomplish core aerification on surface-mined soils because of the rocky nature of the soil. However, because surface mined soils are prone to compaction, the practice is very important, especially on heavily trafficked turf. Aeration is normally done with a tractor drawn device that has revolving hollow tines on a rotating spindle. Some designs utilize a piston type core removal system. In either case the tines penetrate the lawn and remove soil cores. These cores fall on the surface of the lawn and through rainfall, irrigation or dragging, the soil is worked into the turf. The soil serves to reinoculate the thatch layer with microorganisms and create an environment that is conducive to the decomposition of the thatch. This practice also serves to alleviate the negative impact associated with excessive compaction. It is best done when the turf is actively growing to minimize the time that the turf is damaged by the operation. For cool-season grasses the best time to do this is in the spring when the turf is actively growing. Early fall is also an acceptable time, however, turfgrass leaf growth is not as great in the fall and the healing process is slower. Warm-season grasses are best aerified in early summer when they are most actively growing.
Topdressing is the practice of applying a 1/8 to 1/4 inch layer of soil material on the surface of the lawn. This practice does protect the growing crowns and increases the rate of thatch decomposition. It is a laborious and costly process which is not commonly practiced by homeowners. Similar results can be achieved through intensive aeration.
Vertical mowing involves the use of a machine with blades that are perpendicular to the ground and rotate in a manner which removes dead debris and thatch from the turf. These pieces of equipment are often called "dethatchers." Vertical mowing does provide for immediate removal of considerable amounts of thatch and is a curative approach to a thatch problem. Core aerification, on the other hand, is thought of as a preventive approach to thatch management. Vertical mowing should be done during periods when the turfgrass is actively growing to minimize the time required for healing.
Requirements for cultivation will vary greatly between species of turfgrass. Core aeration will be beneficial to all turfgrasses; however, its impact will be greatest on compacted lawns. Topdressing and vertical mowing will not likely be necessary on tall fescue or perennial ryegrass lawns, but may be beneficial to those lawns developing excessive thatch.
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SEE YOUR PHYSICIAN IF SYMPTOMS OR ILLNESS OCCUR DURING OR AFTER USE OF PESTICIDES.
Disclaimer:
Commercial products are named in this publication for
informational purposes only. Virginia Cooperative Extension does
not endorse these products and does not intend discrimination
against other products which also may be suitable.
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