Bermudagrass is an aggressive, low growing and wear tolerant species that spreads by rhizomes and stolons, which help provide a dense, resilient playing surface. Bermuda grows best in full sun and air temperatures between 80 and 95 degrees Fahrenheit. In St. Louis, Missouri, bermuda is most often dormant in late fall, winter and early spring. Unless plants are severely injured during this dormancy period, they are capable of resuming growth as temperatures rise in the spring.

Bermuda varieties vary in color, texture, density, vertical and lateral growth, low-temperature hardiness, disease resistance and method of establishment. Some bermudagrasses do not produce viable seeds and must be established from sprigs or sod, such as Quickstand, Patriot, or, the newest varieties, Latitude and Northbridge. Others can be established from seed: Riviera and Yukon. Riviera and Yukon are very cold tolerant and typically do not get injured from low temperatures. All of these varieties will tolerate mowing heights from ½” to 1 1/2” and adapt very well for sports such as soccer, baseball, softball, lacrosse, and field hockey.

Location, soil type and conditions, and management practices all influence the performance of bermudagrass. Climatic conditions, weed competition and pests can vary from year to year and affect the appearance and performance of bermuda. With bermuda more than most other turfgrass types, how the turf manager responds to conditions and the timing of their fertility and pesticide applications can determine the appearance and performance of the turf for the entire season.

Weed Control

Weeds are commonly found on poorly managed athletic fields. Turf that lacks density and vigor following heavy traffic often open voids (bare spots) in playing surfaces that allow weeds to germinate. Maximizing density will reduce the susceptibility for weed invasion.
Once weeds are present, selection of the proper herbicide is imperative for optimum control. Herbicides to control these weeds can either be a pre-emergent (applied before weed seed germination) or post-emergent (applied to growing weeds). In the middle transition zone found in lower Illinois and central / Southern Missouri, different weeds invade the fields during each season. Pre-emergence herbicides such as Ronstar are used to prevent weed seed germination following aggressive vertical mowing or aeration, as these practices create voids for weed invasion. Ronstar is typically the pre-emergent herbicide of choice for bermuda as it does not adversely affect rooting like other pre-emergence herbicides. Ronstar also allows fields to be sprigged without hampering establishment. Many field managers elect not to apply a pre-emergent in order to have the ability to seed anytime necessary when a field needs recovery.

Other grassy weeds commonly found on athletic fields in our area include crabgrass, goosegrass, and dallisgrass. While these weeds can be controlled with MSMA or DSMA (post-emergent), it should be noted that the Environmental Protection Agency is likely to take these products off the market in the near future.

Alternative chemicals can be used to control certain weeds on athletic fields. For example, Revolver (foramsulfuron) provides postemergence control of goosegrass in bermuda fields. (Include a nonionic surfactant for improved control and two applications might be needed for complete control.)

Purple nutsedge (and other sedges) can be controlled with Prosedge (halosulfuron), Certainty (sulfusulfuron), and Monument (trifloxy-sulfuron-sodium). Broadleaf weeds can be effectively controlled with products combining 2,4-D, MCPP, MCPA, Fluroxypyr, triclopyr, clopyrlid, or dicamba. There are many products containing various combinations of these herbicides available.

Herbicides should be applied to actively growing bermudagrass that is not under heat or drought stress; otherwise phytotoxic injury may occur. To effectively control certain weed species, multiple herbicide applications may be required – some weeds are very competitive when soil and climatic conditions are less than ideal for bermudagrass growth.

The presence of annual bluegrass, broad-leaf plantain, goosegrass, prostrate knotweed or prostrate spurge often signal that the soil is compacted. Black medic and clover may indicate low or deficient levels of nitrogen. Goosegrass and knotweed are often problems on drought-prone sites. Algae, annual bluegrass, and moss often thrive in excessively wet soils. Managing the soil conditions, over time, will favor the turf and weeds will become less problematic.

Managing Soil Compaction

Soil compaction reduces athletic field playing quality. Compaction plus wear and tear are the biggest challenges a sports field manager confronts. Compaction and traffic stress on an athletic field is directly proportional to the amount of use the field receives. Compaction reduces pore space in the soil, which in turn reduces the amount of oxygen and water available for root growth. Additionally, compacted soil reduces the ability of CO2 to escape the soil, which in turn places additional limitations on the plant’s ability to make chlorophyll via photosynthesis. As a result, turf vigor gradually declines and the field will not recover from the stress imposed by foot traffic. Compaction is usually most severe on areas of the field where foot traffic is the most concentrated, such as between the hash marks, in front of goals, and along sideline and bench areas.

Relieving compaction is accomplished through aeration. Hollow tine aeration (removing cores from the root zone) is one of the most important management practices for bermudagrass athletic fields. Core aeration relieves compaction, allows better oxygen and carbon dioxide movement in the soil, encourages deeper rooting, reduces thatch buildup, and increases water infiltration to maintain a drier field (thus reducing further compaction potential). Size of tines, depth of core removed, spacing of tines, and frequency of aeration are important decisions the field manager must make. It is not always the frequency in which you aerify your field, but the amount of surface area you effect. Most heavily trafficked sports fields need monthly aeration during the season. Solid tine/deep tine aeration can be utilized during the period of highest field use without disturbing the surface or affecting ball roll significantly. Few athletic fields exist that would not benefit from aeration during most times of the year.

Managing Soil and Surface Moisture

Soil and surface moisture impact many aspects of bermuda growth and health, as well as athletic field playability. Managing soil and surface moisture should be looked at as an integral part of a management program, both in short-term and long-term planning. Over time, aeration and topdressing help a heavy soil drain better and improve both soil and surface moisture levels after rain events.

Wetting agents break surface tension and improve water infiltration into the soil surface. Retention-type wetting agents retain water to alleviate localized dry spot and are used best during times of drought. Long and short-term wetting agents have different qualities. A long-term wetting agent can work great during extended periods of drought – but a word of caution, if the weather turns to wetter times you lose control of your field – it can create a bigger problem. A short-term wetting agent must be applied monthly, but gives you that control you might desperately need. Different than a wetting agent, which actually affects the chemistry of the water itself, a soil conditioner affects the soil. Soil conditioners such as Peneturf can move water deeply, provide oxygen, and allow quicker use of the field for play following a rain.

Topdressing

Topdressing is the addition of a thin layer of material (in most instances sand) to the turf surface. Topdressing helps control thatch, fills depressions, and can be used following core aeration to improve the soil physical properties. When topdressing, select a sand that will resist compaction, provide proper footing, increase drainage, and prevent layering.

On soil-based fields, select a uniform coarse sand (80% of particles between 1.0 and .5 mm and 90% between 2.0 and .5 mm) to maximize the amount of large (air) pore space in the rootzone. Following aeration, it is recommended that enough sand be applied to fill the holes created by the aerator and leave thin layer on the soil surface. When topdressing as part of a general maintenance program, light, frequent topdressing applications are preferred to less frequent, heavier applications (>1/4”). 1/4” inch depth requires about .8 cubic yards per 1,000 square feet of sand.

Composts can be applied as a topdressing as well. Topdress soil-based fields with 1/8” of compost following aeration to improve the playing surface quality. Once your soil test has 2% organic matter, refrain from additional applications.

Bermudagrass produces new plant parts and “sloughing off” of old leaves, stems, and roots. Thatch layers can form when plants are growing rapidly and the rate of accumulation exceeds their rate of decay. This eventually adds to the organic matter accumulation of the field, thus the continual use of compost would not be advisable.

Disease Management

Bermudagrass is susceptible to several diseases. A combination of three factors is required for the disease to develop – a susceptible host (bermuda), a pathogen (disease), and a favorable environment (weather conditions). Dollar spot, fairy ring, Helminthosporium diseases and spring dead spot can be a problem to bermuda in our area.

The first three are relatively easy to control but spring dead spot can be the most challenging for field managers. Spring dead spot may appear in mature (3-5 year old) bermuda as growth resumes after the winter dormancy period. Each spring, for the next three to four years, the spots appear in the same location and expand. After the second or third year of activity, rings of dead grass may appear.

Bermuda may slowly cover these rings of dead grass during summer. The disease may disappear after three to four years. Rubigan or Tebuconazole can be applied to reduce this disease and should be applied in the spring and fall for best control.

Fertility Practices on Bermuda

“It’s bermuda. Throw some nitrogen at it and it’s fine.” Many have thought this over the years. This thinking is, however, highly shortsighted and will result in poor turf over time. 13 of the 16 nutrients essential for the growth and survival of bermudagrass may be, in fact, supplied by the soil. These mineral nutrients may be classified as primary, secondary or micronutrients.

The primary nutrient required in the greatest amounts by this grass is nitrogen (N). The potassium (K) level in bermudagrass tissue is second to N, and phosphorus (P) ranks third. A soil test is recommended every two to three years to determine the needs of these nutrients. Soils may need secondary and micronutrients to maintain nutrient balance, especially, when grown on sand-based rootzones. Older fields often have plenty of nutrients in the soil but may be tied up and unavailable to the plant.

Granular Fertilizer Guidelines – Not Just Nitrogen
Fertility recommendations will vary based on soil type, bermuda variety, field use schedule and overseeding practices. Ammonium sulfate (21-0-0) is a commonly used and an effective nitrogen source for bermuda. It is important, however, to rotate in more balanced fertilizer analyses that include other plant-essential nutrients and not just N.

Foliar Nutrition – A Useful Tool Often Overlooked
Foliar nutrition can be very effective in providing nutrients to your plant, in particular if your root system is damaged or not functioning correctly. Foliar applications bypass the challenges of nutrient tie-ups in the soil that granular applications fight. Generally, liquid applications require very small amounts of product to be effective and have little chance of burn potential.

Compare products and raw materials to get the best value and most effective product when selecting foliar products. A cheaper per-gallon price doesn’t always equal cheaper per-acre, and there is usually a great tradeoff in efficiency and quality as the price per gallon drops.

Other Fertility And Soil Conditioning Tools To Have In Your Arsenal
Humic acids, microorganism products, fulvic acids, penetrants, and soil algae are tools that will release tied up nutrients in the soil and make them available for plant use. These tools can also provide soil flocculation, which provides more air, less compaction, and a hospitable environment for soil microorganisms to flourish and increase in numbers and diversity. Granular organic products such as Bioflora Crumbles contain these materials and provide these benefits as well.

Repairing Worn Bermuda Areas During the Growing Season: Seeding and Sprigging

When areas of a field become worn to the point that recovery from existing turf isn’t possible, bermuda can be sprigged or overseeded with a seeded variety. Seeding or sprigging bermuda into worn areas will provide better vegetative cover and a better playing surface during more of the playing season. The window for sprigging or seeding bermuda in our region is typically mid-May through mid-July. Bermuda seed will not germinate and sprigs will not grow in spring until soil temperatures have adequately warmed, usually around mid-May.

Also, seeding too early brings additional challenges. These challenges come in the form of heavy competition from spring weeds. Seeding or sprigging any later than mid-July, on the other hand, will give insufficient time for proper establishment before the onset of cold weather.

Seeded bermudagrass varieties are usually planted at the rate of 1 to 3 pounds per 1,000 square feet. Seed should be incorporated no deeper than 1/8” in depth for best germination. Some of the varieties of seeded bermuda used in our area include Barbados, Riviera, Transcontinental, and Yukon. Seeded bermuda needs to have at least 90 days with no competition from cool-season grasses to guarantee a uniform stand and for best survival for the next year.

A couple weeks prior to seeding, remove any competition from cool-season grasses by applying a sulfonylurea herbicide such as Revolver or Monument. These herbicides will control perennial ryegrass in 17 to 24 days following application, depending on temperature and moisture conditions. In addition, these herbicides can also be applied 7 to 21 days prior to overseeding bermudagrass with perennial ryegrass to control early germinating annual bluegrass. Annual ryegrasses will die out in June, without the necessity of removal with herbicides.

Bermuda can also be sprigged. Sprigs purchased from a sod grower can be crimped in with a special sprigging machine. Sprigs should be installed at 600-800 bushels per acre. Some of the varieties available locally include Quickstand, Latitude, and Northbridge.

Managing Dormant Bermuda & Winter Overseeding with Ryegrass

Being a warm-season grass, bermuda goes dormant once the first frost hits. Excess moisture is a serious problem when bermuda is dormant. When the growth of bermuda stops during the fall season, the only drying that can occur is through normal evaporation. Use of penetrant-type wetting agents and soil conditioners, which promote water movement through the soil profile, can be highly beneficial.

To provide color and a better playing surface while bermuda is dormant or transitioning, it is common to overseed with ryegrass. There are two types of ryegrass that a field manager may choose.

Perennial ryegrass, as its name suggests, is a year-round turf and must be sprayed out with a herbicide such as Revolver in late spring to allow the bermuda to thrive. Perennial ryegrass is typically the darkest and densest of the three. The second option is annual ryegrass, which dies out once the heat of summer hits, thus not requiring a herbicide application to remove. While there have been enormous improvements in some varieties of annual ryegrass (SOS from Barenbrug being the absolute best available today), annual ryegrass is neither as dark nor as dense as perennial. Some seed growers/manufacturers have coined the term “transition ryegrass” and call their varieties such. My observations have been that there are annuals and perennials, and nothing in between.

Overseeding fields with ryegrass should be done in mid-September in our area. For optimum results, before overseeding bermuda fields, decrease the mowing height, collect clippings, dethatch and drag with a drag mat. This will improve seed-soil contact and maximize germination. Take care not to mutilate the bermuda when preparing the seedbed or you will increase the potential for bermuda winterkill. Note that ryegrass plants will compete with bermuda for water, nutrients and light – which will reduce the density and overall quality of bermuda. If managing for a pure bermuda stand, and using perennial ryegrass, it really must be sprayed out in spring with herbicide.

Seed Rates and Notes for Overseeding Ryegrass

Annual Ryegrass

  • Seeding rate 10-20#/1,000 square feet (450-900#/acre)
  • ½ to ¾ as expensive as perennial ryegrass
  • Will die out in early summer – does not need to be removed by herbicide application
  • Will establish a few days sooner than perennial ryegrass
  • Will germinate in cooler temperatures
  • Has some potential for winterkill
  • SOS (Super Overseeding) from Barenbrug is highest quality blend available

Perennial Ryegrass

  • Seeding rate 10-15#/1,000 square feet
  • Use turf type perennial ryegrass varieties and not common types
  • Excellent color, fine texture, and dense
  • Has excellent winter tolerance
  • Slightly slower to establish than annual ryegrass
  • Must be taken out with a herbicide in late spring/early summer in order to allow the bermuda to recover
  • RPR (Regenerating Perennial Ryegrass) from Barenbrug is highest quality blend available