Buckeye Turf Newsletter (Summer 2026)

By Tyler Carr, Ph.D.

Welcome to the summer 2026 edition of the Buckeye Turf Newsletter. Faculty, staff, and graduate students from the Turfgrass Science program at The Ohio State University created this quarterly publication to provide timely and relevant recommendations for turfgrass managers in Ohio and the Midwest region. The articles we write are based on feedback we receive from you, so please complete the survey to let us know how we are doing and to suggest future article topics.

OSU Turfgrass Research & Education Field Day

August 4, 2026

Columbus, OH

Ohio Lawn Care Association Field Day

August 5, 2026

Columbus, OH

Ohio Turfgrass Foundation Conference & Show

December 8-10, 2026

Columbus, OH

By Shaohui Wu, Ph.D.

This spring we experienced a bizarre climate situation with vast temperature fluctuations that affected insect populations including the annual bluegrass weevil (ABW) (Figure 1). The early warm spring pushed forward the migration of overwintered weevils and egg-laying on short-mown turf, advancing the 1st-generation larval development 10-14 days comparing to last year. This also moved forward the timing of treatment applications. It was once predicted that the ABW damage would occur earlier this year until May, when the season corrected itself and cool temperatures slowed down the stage progression. As a result, the damage still appeared in late May-early June, which is usual for the OH climate. Control failures have been reported, especially at new sites of ABW infestation, likely due to wrong timings of treatment associated with the climatic impact this spring. What we have learned from this lesson is that experience is not always reliable under unpredictable conditions, under which scouting is critical to check the pest status for timely implementation of management practices.

Without doubt, the territory of ABW is expanding in OH with increasing sites of infestation. Often, this tiny weevil gets unnoticed until it builds up the population to a level causing turf damage (Figure 2). A simple way to check its presence and population size is conducting soap flushing (i.e., mixing 1 fluid ounce of dish detergent per gallon of water and evenly applying two pints per square foot), which is effective for scouting surface-active critters including ABW adults. However, this method should be used targeting the correct stages (i.e., when weevils are present), and frequent scouting can be used to determine the time of peak adult activities for adulticide application. Other than adult scouting, ABW larval populations can be monitored using saline extraction [i.e., soaking quartered turf cores (taking with a turf plug) in warm saturated salt solution (10% weight/volume) and stirring every 15 min for 1 h to float up all ABW stages]. These scouting practices can be used to identify ABW problems and take actions before damage occurs.

Since ABW can develop up to three generations per year, the discrepancy of stages increases as the season progresses. Hence, most management efforts have been focused on overwintered adults and the 1st generation larvae before the population expands. However, subsequent treatments can be made, especially following control failures. During summer, turfgrass swards can be stressed by environmental and disease pressures, in addition to pests. Hence, plant tolerance to ABW feeding can be lower than the usual threshold of 30-50 larvae/square foot and 10 adults/square foot. If the 1stgeneration-ABW was unnoticed or not controlled successfully, it can further build up the population and cause summer damage, especially when turfgrass is under stress. It’s highly recommended to continue scouting ABW stages and take actions as needed.

In July, insecticide applications made for ABW management can also control some other major turfgrass pests (e.g., white grubs, billbugs, caterpillars, etc.). The chemicals may include anthranilic diamides (tetraniliprole, chlorantraniliprole), neonicotinoids (clothianidin), and some combination products (such as clothianidin plus bifenthrin). Among these chemicals, bifenthrin has a short residual and does not provide grub control; while it is effective for surface-active pests including ABW adults and others, it should be used with caution if targeting pyrethroid-resistant populations. To avoid potential resistance development or build-up, it is critical to rotate chemicals from different classes when choosing products and only use insecticides on a needed basis (i.e., when pest populations reach threshold levels).

• The ABW is expanding its territory in OH with increasing sites of infestation and control failures reported.
• Climatic conditions affected ABW activities and timing of treatment applications in spring 2026.
• Scouting is the key to detect ABW populations and assess the necessity and timing of spray.
• Effective chemical rotation is critical to reducing resistance development.
• A single application made in July can target multiple turfgrass pests including ABW.
• Watching out for potential damage from the 2nd and 3rd ABW generations under environmental and/or disease stresses in July and August, especially if the 1st generation was not successfully controlled.

By Pam Sherratt

A recent visit to England provided an opportunity to compare turfgrass management in Liverpool with practices commonly used in Ohio. Although both regions support cool-season turfgrass, differences in climate, environmental regulations, and management philosophies result in distinctly different approaches to maintaining high-performance sports surfaces.

Ohio has a humid continental climate with substantial temperature extremes, while Liverpool has a temperate maritime climate with relatively mild conditions year-round. Latitude also influences turf management. Ohio lies at approximately the same latitude as Madrid, Spain, whereas Liverpool is comparable to Alberta, Canada. As a result, Liverpool experiences nearly 17 hours of daylight in July but only about 7½ hours during midwinter.

These climatic differences directly affect turfgrass management. Ohio's hot, humid summers create greater disease pressure while increasing heat and drought stress. Liverpool's cooler climate reduces heat stress but presents challenges associated with limited winter sunlight. Interestingly, temperatures approached 100°F immediately before and after our visit, an exceptionally rare event that illustrates increasing weather variability.

Both regions rely primarily on cool-season turf species. Perennial ryegrass dominates English football pitches because of its rapid establishment, wear tolerance, and adaptation to the maritime climate. In Ohio, perennial ryegrass is commonly mixed with Kentucky bluegrass and tall fescue to improve recovery, stress tolerance, and overall performance.

Environmental regulations also influence management decisions. The UK has strict pesticide regulations, encouraging greater reliance on IPM and alternative approaches. For example, some clubs use garlic-based products to suppress plant-parasitic nematodes rather than conventional pesticides.

Everton Football Club's new stadium demonstrated how technology is increasingly integrated into modern turf management. The pitch incorporates recycled-water irrigation, vacuum-assisted drainage, and a hybrid natural grass system reinforced with synthetic fibers to improve stability and wear tolerance. Grow lights compensate for shade caused by the stadium roof, while UV-C technology is currently being evaluated as a non-chemical tool for disease suppression. Surface sensors/pods continuously monitor things like volumetric water content, salinity, and temperature, providing real-time data for the grounds crew.

Equipment selection also reflects an emphasis on sustainability and worker safety. Most maintenance equipment is electric, reducing emissions and operator exposure to vibration. Grounds staff at Everton wear vibration monitors on their wrists that track daily exposure to help prevent vibration white finger, an irreversible occupational injury associated with prolonged use of vibrating equipment. Each machine has established operating limits, and exposure data is monitored to ensure safe working conditions.

Everton also relies exclusively on walk-behind mowers rather than ride-on units for stadium maintenance. Although more labor-intensive, walk-behind mowing minimizes surface compaction while providing greater cutting precision and consistency. Interchangeable mower cassette systems further improve efficiency by allowing rapid transitions between mowing, grooming, and verti-cutting operations.

Everton's intensive event schedule presents another management challenge. In addition to Premier League matches, the venue hosts other games, concerts, and corporate events, leaving only about three weeks for field renovation before the next season. To meet this narrow window, the grounds staff will install mature sod this summer before stitching hybrid fibers into the new surface.

We also visited Manchester United Football Club, where the grounds team was completing its first major pitch renovation in 14 years. The project involved replacing the rootzone before installing a new hybrid playing surface. The renovation also included player safety improvements by extending the natural grass surface slightly closer to the pitch perimeter, creating a more consistent playing surface before the steep side-slopes begin. Protective padding was also installed over the surrounding brickwork to reduce the risk of injury when players leave the field at speed. Although a new stadium is planned, the club viewed these upgrades as essential for maintaining both performance and player safety.

Our final stop was Royal Birkdale Golf Club, host of the 154th Open Championship. Beyond being one of the world's premier links courses, Royal Birkdale is designated a Site of Special Scientific Interest. Course management must balance championship playing conditions with protection of a fragile dune ecosystem supporting species such as the protected natterjack toad and red squirrel. Assistant Superintendent Tom Jaques, an alumnus of The Ohio Program, demonstrated how ecological stewardship and championship turf management can successfully coexist.

The visit reinforced that successful turfgrass management extends far beyond producing quality playing surfaces. Climate, environmental regulations, technological innovation, worker safety, and ecosystem conservation all influence management decisions, illustrating how turfgrass science continues to evolve to meet both performance and sustainability goals.

By Tyler Carr, Ph.D.

Ohio summers can bring hot and dry conditions, leading to droughty, brown lawns. The choice to irrigate is ultimately related to homeowner expectations. The goal of this article is to align expectations with irrigation recommendations. Three different expectation scenarios are provided below, each of which align with unique recommendations.

This homeowner’s lawn will almost certainly require irrigation each summer, but likely not as much irrigation as one may think. I suggest applying irrigation to lawns ONLY once drought stress symptoms (i.e., wilting) are visible. To determine if a lawn is wilting, walk across it. If the leaves do not “bounce back” after walking across, the turfgrass is likely under water-deficit stress. Once wilting is observed, irrigate the next morning prior to 9 AM with enough water to reach the deepest roots without surface runoff. Runtimes will vary depending on whether irrigation is applied with an in-ground or portable system. Generally, in-ground systems apply more water than portable systems; therefore, in-ground systems require shorter runtimes than portable systems.

Using this irrigation approach, most high-quality lawns will receive irrigation no more than 2 to 3 times each week during the hottest and driest stretches of summer. Lawns irrigated daily are likely either receiving too much water or are not irrigated deeply enough to reach the deepest roots.

Most years, this lawn will require no supplemental irrigation. Ohio typically receives enough timely summer rainfall to rehydrate lawns that have entered dormancy. Dormant lawns are not dead but have entered a state to preserve metabolic function under water-deficit stress. In some years, prolonged drought conditions will force homeowners to decide how much brown turf is acceptable before irrigation.

When/if irrigation is needed for these lawns, many irrigation events may be necessary to move sufficient water through the soil profile. After long drying periods, soils can be very difficult to rewet initially. Once the soil is sufficiently rewetted, subsequent excessive irrigation is not needed for turf to recover. With adequate soil moisture, the rate of lawn recovery will depend on other conditions, such as temperature. For example, lawns will recover more quickly in the cooler autumn months than summer.

Lawns as a system in Ohio do not necessarily require irrigation but may be necessary for some depending on their functional and aesthetic goals. In many cases, lawns without any summer irrigation will survive and perform well during spring and autumn. In some cases, such as 2024 and 2025, drought-induced turf loss from crown dehydration can result. These areas may need to be reestablished from seed if a uniform turf stand is desired. Otherwise, weeds will likely fill into these voids.

You may have heard the recommendation to apply 0.25 to 0.50 inches of water every 2 to 4 weeks during period of no precipitation to ensure turfgrass crowns remain hydrated without encouraging the turf to exit dormancy. While crown hydration is critical for turf survival during prolonged drought stress, I struggle to find the source of this information and suspect that it is an anecdotal recommendation instead of an evidence-based recommendation. However, the absence of evidence is not the evidence of absence.

I support periodic irrigation during prolonged dormancy, but the requirements will vary depending on species, cultivar, and/or site characteristics (slope, shade, soil texture, etc.). For example, turf-type tall fescue is generally more drought resistant than Kentucky bluegrass and perennial ryegrass, possibly requiring lower irrigation frequency or volumes. Within species, cultivar selection matters too. Independent research efforts, such as the Turfgrass Water Conservation Alliance (which OSU participates in), certify cultivars that demonstrate reduced water requirements compared to standard cultivars.

Turf quality and function expectations drive irrigation decisions. Are your irrigation practices aligned with your expectations?

By Brenda A. Medina Privatt

I am a second-year master’s student co-advised by Drs. Florence Sessoms and Edward Nangle, and my research project focuses on the development and assessment of a soy-based slow-release granular fertilizer for use in home lawn. Perennial turfgrass systems, widely used in residential yards, face criticism for their heavy reliance on fertilizers, pesticides, and irrigation. In recent decades, breeding strategies and sustainable management practices, including the adoption of slow-release fertilizers such as coated urea, have been implemented to reduce input requirements while maintaining a steady nitrogen (N) supply for plant nutrient demands. However, coated urea is potentially problematic because its polymer coatings are often non-degradable. Moreover, synthetic fertilizers contribute to environmental impacts, including N runoff fueling algal blooms which degrade water quality, while non-degradable coatings introduce microplastics that alter soil biological, physical, and chemical properties, and may negatively affect plant performance. Building on these challenges and the need for sustainable N solutions, my research project aims to design a sustainable, plant-based alternative for lawn fertilization using soybean flour, a low-cost and abundant product of the U.S. soybean industry.

The first phase of the study started in January 2025 through September 2025 and involved formulating soybean flour into granular pellets that can be applied with standard fertilizer spreaders. Pellets were coated with polylactic acid, a biodegradable and environmentally friendly polymer, to ensure slower nutrient release and reduce N leaching.

The second phase began in July 2025 and is still ongoing. It has focused on collecting data under greenhouse (perennial ryegrass) and field (mixed-species lawn) conditions to evaluate visual turf quality, Normalized Difference Vegetation Index (NDVI), green cover, and soil characteristics. Initial observations suggest that turfgrass systems fertilized with different soy-based formulations perform similarly and better than the non-fertilized treatment, also known as the negative control treatment, under greenhouse conditions. From the 1st year field trials, there was no significant difference across treatments including the negative control treatment. However, during this 2nd year, preliminary observations from field trials suggest that treatments perform better than the negative control plots. Those treatments include soy flour liquid formulation, soy pellets, coated urea, and Corn Gluten Meal (CGM).

The primary nitrogen (N) sources applied to turfgrass systems are urea and/or its derived products which inadequately applied results in N leaching or runoff as nitrate. Real world case scenarios of N runoff impact are the worsening of hypoxia in the northern Gulf of Mexico and the algal bloom in Lake Erie caused by agricultural trends. These novel pellets were applied to perennial ryegrass grown in pots with growing media under greenhouse conditions to assess potential nitrate leaching. They were compared with urea, coated urea, and soy flour liquid formulation performance, and results showed that urea treatment presented more leachate nitrate concentration than both soy pellet and coated pellet treatments which performed similar to coated urea treatment.

By Tyler Carr, Ph.D.

How do I amend Ohio soils for better growing conditions?

The finer-textured Ohio soils, particularly excavated soils from residential construction, can bring water retention and nutrient-holding capacity challenges. Regardless of a lawn’s specific soil challenges, physical soil disruption or modification can improve growing conditions. Below are three solutions, ranging from the lowest to greatest friction required to implement.

For poor-performing native soils, core aeration can improve water and air movement, while reducing soil compaction. Core aeration is the physical removal of soil plugs (typically 3 inches deep). These benefits are generally limited to the areas physically affected by core aeration. You may be surprised that typical drum-style lawn aerators only affect up to ~5% of the total lawn area in a single pass, which depends on aerator tine diameter and spacing. Therefore, a single aerator pass is often insufficient to alleviate soil compaction and measurably improve water and air movement. In most cases, 2 to 3 passes over a lawn are necessary to ensure enough holes are created.

While we are discussing aeration, an important note is that core aeration is different from spike or liquid aeration. While spike aeration can improve air and water movement through a soil, it does not alleviate compaction. In terms of liquid aeration, previous research from the University of Georgia concluded “… liquid aeration is not a viable replacement for mechanical cultivation methods like hollow-tine aerification for the remediation of soil compaction in turfgrass systems.”

If you have heard me discuss fertilization, I generally support reduced nitrogen fertilization for lawns. Ohio soils from residential construction often have high amounts of clay and low organic matter. Soils with low organic matter tend to struggle retaining plant available nutrients. Over time, lawn systems will develop their own organic matter through decaying roots, crowns, and stems. One can accelerate this process through additional nitrogen fertilization, up to 6 lb N per 1,000 square feet per year, with 50-75% applied in the autumn months. This is not a long-term program—I suggest trying this for 1-3 years while monitoring turf conditions. This solution will likely result in excessive turf growth, so prepare to mow frequently enough to adhere to the one-third rule and keep those blades sharp.

The most time-consuming and expensive intervention will likely yield the best result. If growing conditions need to improve more quickly than the previous two solutions, consider physically amending your soil by incorporating material that improves nutrient-holding capacity and reduces compaction. This process is most effective when weed-free, screened topsoil or compost is added in a 1–2-inch layer and tilled into the top 4-6 inches of the existing soil. It is not recommended to apply this material directly to the surface without incorporating through tillage, as this will likely negatively affect water movement through the newly-created soil interface. If topdressing into existing lawns, apply no more than 0.25 inches of material in each application. If using compost, please review the guide from Penn State University for selecting compost material for lawns.

Purpose: A quick, scannable list of timely tasks and reminders for the season.

By: Dave Gardner, Ph.D., Pam Sherratt, and Shaohui Wu, Ph.D.

• Commit to regular irrigation or let the lawn go dormant.
• Spot spray to control annual grasses, sedges and broadleaf weeds. Avoid applications to drought stressed turf or when temperature is above 80 degrees.
• On areas to be renovated/reseeded this fall begin application of non-selective herbicide about August 1. Best time to establish from seed is August 15-Septpember 30.
• If using mesotrione to remove bentgrass from cool season turf, begin treatments in early-mid July and make 3 applications 2-3 weeks apart so that the last application is between August 15 and September 30. With the third application, apply seed, then spray mesotrione, mulch and then begin irrigation.
• Trafficked turf: Apply 0.5–1.0 lb of slow-release nitrogen per 1,000 sq. ft. per month to promote growth. Irrigate deeply 1–2 times per week, providing a total of 1.0-1.5 inch of water (higher amounts when evapotranspiration is high). If possible, carry out maintenance early in the morning to avoid further stressing the turf.
• Use fungicide-coated seed if regularly seeding with perennial ryegrass in high-traffic areas, such as sidelines and goalmouths.
• Be extra vigilant for disease, which can be difficult to diagnose. Destructive diseases like gray leaf spot can initially resemble drought stress.
• Preventive grub control with neonicotinoids or anthranilic diamides labeled for white grubs by mid-August, especially for sites with historical infestations or adult beetle flights spotted.
• Scout for grub populations in soil from mid-August to mid-September and apply curative control (with trichlorfon, clothianidin, etc.) if reaching threshold levels (≥ 10 grubs per square foot); water in with ¼ - ½ inch of irrigation post treatment.

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