Turfgrass Epistemology

In this video, I explore the recent review article “Review of the Biology and Management of Large Patch of Warm-Season Turfgrasses” (Kreinberg et al., Crop Science, 2025). I walk you through what the authors tell us about Rhizoctonia solani AG 2-2 LP — the fungal pathogen behind large patch disease in warm-season turfgrasses — how environmental conditions favor its development, and how it can persist in thatch through seasonal dormancy. Along the way, I highlight the state of current cultural, chemical, and biological control strategies, and I point out the gaps and future directions the turfgrass pathology community still needs to address. If you’r...

In this video, I take you through the state of the science on dollar spot disease in turfgrass, framed by the recent review “New Approaches to an Old Problem: Dollar Spot of Turfgrass.” We explore how this ubiquitous fungal disease (caused by Clarireedia spp.) continues to challenge turf managers, why traditional fungicide programs are increasingly under pressure, and what new genomic tools and breeding strategies may offer as solutions. I’ll break down the authors’ discussion of pathogen genomics, host–pathogen interactions, and quantitative trait loci (QTL) for resistance, while also reflecting on where future research might be headed. Whether yo...

In this video, I dive into the article “Survey of Water Use and Management Practices on US Golf Courses from 2005 to 2024” published in HortTechnology (Shaddox et al., 2025). The study tracks nearly twenty years of changes in how golf courses across the United States use and manage water. I discuss how irrigation volumes and irrigated areas have shifted over time, highlight important regional differences, and explain why some water sources—like recycled water—are declining while others remain steady. I also cover the adoption of new management strategies such as moisture sensors, irrigation audits, and objective scheduling, along with the continui...

In this video, I discuss the YouTube episode “Struggling Turf? Calcium Could Be the Missing …” and examine it through the lens of the strawman fallacy. We’ll look at how someone can present information that is technically true, yet still mislead by reframing the issue or knocking down an argument no one actually made.

This breakdown shows how a conman can be both truthful and deceptive at the same time—a powerful reminder of why critical thinking matters in turfgrass science, lawn care, and beyond.

If you’ve ever learned something useful from this channel, please consi...

In this video, I review the scientific article “Irrigation Frequency Affects Zoysiagrass Rooting and Plant Water Status.” We’ll look at how different irrigation schedules influenced root development and water relations in zoysiagrass, and what these findings mean for turfgrass management. If you’ve ever wondered how often you should water to encourage deeper roots and better turf performance, this study offers valuable evidence-based insights.

Article: https://journals.ashs.org/view/journals/hortsci/31/2/article-p234.xml

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In this episode, I break down the claims made in “Check out These Roots, John Perry! | [LIVE PODCAST] Ep.8 of the Average Joe Lawn Care Show,” where the hosts argue that liquid aeration is an effective solution for lawn health. I dive into the science and present evidence that challenges their assertions. With years of turfgrass science experience, I explain why liquid aeration doesn’t deliver the promised results and why relying on this product could lead to misguided lawn care practices. Don’t fall for the hype – join me as I debunk the myths and set the record straight w...

In this video, I take a look at some of the recent comments and questions from TikTok and YouTube. Your feedback not only shapes the conversations we’re having here but also sparks deeper discussions about turfgrass science and management.

I’m also excited to introduce a new fundraiser supporting turfgrass research. Turfgrass plays a vital role in sports, recreation, and landscapes, yet research in this area often goes underfunded. Your support will help advance studies that improve sustainability, water use efficiency, soil management, and turf quality—work that benefits golf courses, sports fields, parks, and home lawns...

In this video, I explore the findings of the research article “Tall Fescue Rooting as Affected by Deficit Irrigation” (HortScience, Volume 42, Issue 3). The study, conducted by Jinmin Fu, Jack Fry, and Bingru Huang and published June 1, 2007, investigates how reduced irrigation impacts the rooting behavior of 'Falcon II' tall fescue grasses using minirhizotron imaging.

I’ll walk through:

The study’s experimental setup using varying levels of evapotranspiration (20%, 60%, and 100%)
Key findings such as the surprising increase in root length and surface area under severe water stress (20% ET)
Practical implications for turfgrass management and water conservati...

In this video, I examine the research by Cain et al. (2022) that explores how varying irrigation schedules affect the encroachment of annual bluegrass (Poa annua) into perennial ryegrass turf systems in western Oregon. The study reveals that watering once per week significantly reduces annual bluegrass encroachment compared to irrigating four times a week, and that replacing irrigation volumes based on reference evapotranspiration (ETref) had no meaningful impact on that outcome

Throughout the video, I walk viewers through the experimental approach, highlight the implications for turfgrass managers aiming to suppress undesirable bluegrass without altering evapotranspiration-based irrigation schedules, an...

In this video, I discuss the scientific article "Irrigation Rates and Frequency Affect Tall Fescue Color and Weed Encroachment." We’ll examine how adjusting irrigation amounts and timing influences turfgrass aesthetics and weed pressure. From water conservation to maintaining turf quality, this study provides valuable guidance for anyone managing tall fescue under variable moisture conditions.

https://onlinelibrary.wiley.com/doi/full/10.1002/its2.184

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In this video, I review the scientific article "Irrigation Frequency and Amount Effect on Root Extension during Sod Establishment of Warm-season Grasses." We’ll explore how different irrigation strategies influence root growth during establishment, what this means for practical turfgrass management, and how to strike the right balance between watering efficiency and sod performance. If you manage turf or are curious about water-wise establishment practices, this study offers some important insights.

https://journals.ashs.org/view/journals/hortsci/46/8/article-p1202.xml?rskey=SDm3zj&print

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In this video, I offer commentary on the scientific article titled "Water use and performance of Kentucky bluegrass influenced by cultivar, irrigation practices, and soil texture," published in the International Turfgrass Society Research Journal (DOI: 10.1002/its2.200).

The study evaluated two Kentucky bluegrass cultivars, Mallard and Geronimo, grown in lysimeters filled with either loamy sand or silt loam. Each setup was subjected to two irrigation levels: 40% and 80% replacement of reference evapotranspiration. The authors monitored water use and turf coverage throughout the growing season to assess drought resilience.

My commentary covers the key findings from the research...

In this video, I dive into the 2002 study from Crop Science that evaluates how different irrigation schedules, tall fescue cultivars, and mowing heights interact to shape turf performance.

Article: https://acsess.onlinelibrary.wiley.com/doi/full/10.2135/cropsci2002.2011

✅ What you'll discover:

Study design highlights: 2‑year field trial in Riverside, CA, comparing 2–4 irrigation events per week at ~80 % ET₀, two cultivars (a dwarf vs. a turf-type), and two mowing heights (~3.8 cm vs. 6.4 cm)

Key findings: Twice-weekly “deep” watering yielded the highest visual quality. Dwarf cultivars and shorter mowing height boosted turf quality early, but overwatering and m...

In this video, I respond to the Bermuda Grass Central video “The Best Summer Fertilizer for Lawns? Why Yard Mastery 7‑0‑20 is …”. I break down their main arguments, evaluate their fertilizer recommendations, and highlight both strong and weak points.

✅ What you’ll get:

Summary of Claims: A quick overview of the video’s main points—why the creator supports Yard Mastery’s 7‑0‑20 blend for summer turf.

Critical Analysis: Comparing their claims to current turf fertilization research—does a high-potassium, zero-nitrogen mix really benefit warm-season grasses in mid-summer? I'll cite recent studies and best management practices.

Pros and...

In this video, I critique “Found the Best Iron to Apply to Your Lawn For Summer Color” by a former golf course superintendent. While I agree that iron can boost turf color without pushing growth, I question some of the application advice—especially the dosing schedule and lack of soil pH context.

I break down what the original video gets right, what it misses, and share my evidence-based tips for using iron effectively this summer. If you want deep green turf without wasting money or product, this video’s for you.

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In this video, I break down the findings from the scientific article "Optimizing Irrigation Rates and Frequency for Perennial Ryegrass in Western Oregon." We’ll look at how different irrigation strategies affected turf quality and what this means for managing ryegrass under Pacific Northwest conditions. Whether you’re a turf manager or a lawn care enthusiast, this research has practical takeaways you can use.
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On this episode of Turfgrass Epistemology, Dr. Dan Sandor joins me to break down his study that addresses one of the most commonly misunderstood aspects of turf establishment: how much water should you really apply when seeding a new lawn?

Sandor et al. (2021) evaluated daily irrigation at 50%, 75%, 100%, and 125% reference evapotranspiration (ETo) to determine how quickly tall fescue and bermudagrass cultivars reach full coverage. The big takeaway? Applying more than 100% didn’t help, and drought-resistant cultivars didn’t show any special advantage during establishment.

In this video, we discuss:

    💧 Why 100% ETo is the sweet spot for...

In this episode of Turfgrass Epistemology, we dive into a study from Oregon State University that looked at how turfgrass species and mowing height affect water requirements in western Oregon. The results might surprise you—tall fescue and perennial ryegrass significantly outperformed fine fescues when it came to conserving water.

We’ll break down the data on evapotranspiration replacement, irrigation intervals, and how mowing height can influence your watering schedule. Should you mow higher? Should you convert to tall fescue? This video gives you practical, science-backed guidance on how to choose and manage turfgrasses for water conservation.

In this episode, I dive into the comment section and my inbox to respond to the most interesting, insightful, and downright puzzling messages I’ve received from viewers. From soil test questions and fertilizer theories to passionate turf debates and a few questionable product claims—nothing is off limits.

Whether you're here to learn, laugh, or just see if your message made the cut, this video is a behind-the-scenes look at the community that makes Turfgrass Epistemology what it is.

Let’s talk turf, tackle misinformation, and maybe share a few facepalms along the way.

...

In this episode, I dive into the comment section and my inbox to respond to the most interesting, insightful, and downright puzzling messages I’ve received from viewers. From soil test questions and fertilizer theories to passionate turf debates and a few questionable product claims—nothing is off limits.

Whether you're here to learn, laugh, or just see if your message made the cut, this video is a behind-the-scenes look at the community that makes Turfgrass Epistemology what it is.

Let’s talk turf, tackle misinformation, and maybe share a few facepalms along the way.

...

In this video, I critically examine the advice presented in "How to Fertilize in Hot Weather. Dog urine spot prevention, fungus recovery, general fertilizer." While the original video offers practical tips on lawn care during hot weather, it's essential to scrutinize the recommendations to ensure they align with best practices and scientific understanding.

Key Points Discussed:
- Fertilizing in High Temperatures: Assessing the risks and benefits of applying fertilizer during peak heat and its impact on lawn health.
- Dog Urine Spot Prevention: Evaluating the suggested methods for preventing and treating urine spots caused by...

In this episode of Turfgrass Epistemology, we analyze a pivotal field study that tested the drought resistance and irrigation needs of five common turfgrass species under real-world conditions in northern Texas. Using a unique linear gradient irrigation system, Qian and Engelke evaluated how ‘Tifway’ bermudagrass, ‘Meyer’ zoysiagrass, ‘Rebel II’ tall fescue, ‘Prairie’ buffalograss, and ‘Nortam’ St. Augustinegrass performed under a wide range of watering regimes—from excess irrigation to complete reliance on rainfall.

What did they find? Not all turfgrasses respond the same way to drought—or to overwatering. Some thrived under low water input, while others demanded more than expec...

He flashes university research to sell Air 8—but is it the whole story? In this video, I break down the science he didn’t show you. Liquid aeration sounds impressive, but does the data actually support the hype? Let’s dig into what the university study really says—and what he conveniently left out. If you're serious about turfgrass and tired of marketing spin dressed up as science, this one's for you.

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Which Grass Survives Water Restrictions? Science Has the Answer.
On this episode of Turfgrass Epistemology, we dive into a long-term study that puts warm-season turfgrasses to the test under real-world municipal water restrictions. Which species held up best when irrigation was limited to once or twice a week? How do turf quality, coverage, and drought resilience stack up over time?

Join me as we examine what the science actually says—not the marketing claims—about how Zoysia, Bermuda, and other species perform under regulated irrigation frequencies. This research has big implications for homeowners, sports fields, golf cour...

You've seen the ads: "Liquid aeration breaks up soil compaction—no plugs, no mess!" But does it really work? This video dives into a new peer-reviewed study that compares liquid aeration products (humic acids, seaweed, fertilizer blends) with mechanical hollow-tine cultivation on hybrid bermudagrass fairways.

The results are eye-opening.

✅ Did liquid aeration improve turf health?
✅ Can it reduce compaction like traditional aerification?
✅ What really increases water infiltration and rooting?

Whether you're a turf manager, lawn care professional, or homeowner chasing the perfect lawn—this evidence-based review will help you separate marketing hype from...

Is "fast green" always the right goal? In this episode, I critique the video [How to Get a GREEN LAWN FAST] and unpack the science behind the three quick tips it promotes. Are these practices sustainable—or just shortcuts with hidden consequences? Join me as we separate turfgrass fact from flashy fiction.

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Discover how tall and hard fescue respond to water stress in this deep dive into the science of deficit irrigation. In this episode, we explore a peer-reviewed study that reveals how reduced water inputs affect turf performance, rooting, and drought resilience. If you're managing turf in a water-limited environment, this research has critical insights you don't want to miss.

article: https://acsess.onlinelibrary.wiley.com/doi/abs/10.2135/cropsci1989.0011183X002900060045x

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In this episode of Turfgrass Epistemology, I provide commentary on the scientific article "Effect of Irrigation Frequency on Turf Quality, Shoot Density, and Root Length Density of Five Bentgrass Cultivars." We examine how irrigation intervals influence turfgrass performance, with a focus on shoot density and root development. I discuss the experimental design, key findings, and what this research means for managing bentgrass under varying irrigation regimes. If you're interested in evidence-based turf management, this one's for you.

Article: https://acsess.onlinelibrary.wiley.com/doi/abs/10.2135/cropsci2003.2820

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In this episode of Turfgrass Epistemology, I provide commentary on the scientific article "Irrigation frequency effects on Prizm zoysiagrass establishment from sprigs." We examine how different irrigation intervals influenced establishment speed, coverage, and quality during early growth. I break down the study’s design, highlight the key findings, and discuss how the results apply to real-world turf management decisions—especially for professionals establishing zoysiagrass from sprigs.

article: https://acsess.onlinelibrary.wiley.com/doi/10.1002/agg2.70000

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In this episode of Turfgrass Epistemology, we put artificial intelligence to the test by asking it turfgrass management questions—fertility, irrigation, mowing, and more. Can AI provide sound, evidence-based answers, or does it fall into common misconceptions? As a soil scientist, I evaluate its responses and reveal what the science actually says.

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In this episode of Turfgrass Epistemology, I review the scientific article "Physiological Response of St. Augustinegrass to Irrigation Scheduling." We explore how different irrigation strategies impact turf health, drought stress, and water use efficiency. As a soil scientist, I break down the study’s methods and findings to understand what truly benefits St. Augustinegrass under varying moisture conditions.

article: https://acsess.onlinelibrary.wiley.com/doi/abs/10.2134/agronj1984.00021962007600020024x

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In this episode of Turfgrass Epistemology, I sit down with Dr. Matteo Serena to discuss his paper, "Optimizing Frequency and Amount of Irrigation Needed to Establish Cool-Season Turfgrasses." We explore the key findings, practical applications, and how this research can improve turfgrass establishment strategies. Join us for a deep dive into the science behind efficient irrigation and better turf management.

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On this episode of Turfgrass Epistemology, I discuss some of the recent comments, emails, and Twitter conversations related to turfgrass science. From thoughtful questions to common misconceptions, I highlight the importance of critical thinking and scientific evidence when evaluating turf management practices. Join me as we explore how public discussions shape what we know—and how we can sharpen our understanding of turfgrass through better communication.

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Join me, a soil scientist, as I delve into the classic educational film "Water Movement In Soils" (https://youtu.be/DmTNFIEc2VA). This video, produced by Washington State University in 1959, provides a foundational understanding of how water moves through different soil types, highlighting the roles of soil texture, structure, and layering.​
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In my commentary, I explore key concepts such as capillary action, infiltration, and percolation, and discuss how these processes affect soil health and plant growth. I also examine the implications for modern soil management practices, including irrigation strategies and soil amendment techniques.​

Whet...

In this video, we delve into the 1985 study by Peacock and Dudeck, titled "Effect of Irrigation Interval on St. Augustinegrass Rooting," published in the Agronomy Journal. The research examines how varying irrigation intervals—every 2, 3, 4, or 6 days—impact the root mass and length density of St. Augustinegrass. Interestingly, the study found that root development remained unaffected across these intervals, suggesting that less frequent irrigation may not compromise root growth. These findings have significant implications for turfgrass irrigation practices, potentially leading to more efficient water usage without sacrificing turf quality.​

Read the full article here: https://doi.org/10.2134/agronj1985.00021962007700050034x​

In this video, I break down the science behind the article “Short-term soil carbon mineralization on golf course sand-based putting green and its effect on creeping bentgrass nitrogen uptake.” What does this research tell us about nitrogen cycling, microbial activity, and nutrient availability in high-performance turf systems? Let’s dive into the data and talk implications for turfgrass management.

📢 Watch, learn, and share your thoughts in the comments!

 Zhou, Q., Soldat, D. J., & Ruark, M. D. (2024). Short-term soil carbon mineralization on golf course sand-based putting green and its effect on creeping bentgrass nitrogen uptake. Crop Science, 6...

As a soil scientist, I’m breaking down the claims made in the video “Stop Overseeding! There’s a Cheaper Way!!” — let’s talk turfgrass science, soil fertility, and whether the advice holds up under scrutiny. Is there really a better, cheaper alternative to overseeding? Let’s find out.

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Does the FASTEST Way To Get ANY Lawn Green actually work, or is it just another lawn care myth? As a soil scientist, I break down the claims, analyze the science behind turfgrass nutrition, and reveal what REALLY makes a lawn green—fast and sustainably.

🌱 Is this method safe and effective?
⚠️ Are there hidden downsides?
🔬 Let’s separate fact from fiction using real soil science!

📢 Watch, learn, and share your thoughts in the comments!

#LawnCare #SoilScience #TurfgrassManagement #GreenGrass #FertilizerFacts

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How can Solvita soil tests help predict turfgrass response? In this video, we break down key findings from the scientific article "Predicting Cool-Season Turfgrass Response with Solvita Soil Tests, Part 1: Labile Amino-Nitrogen Concentrations." Learn how labile amino-nitrogen measurements can provide insights into soil fertility and turfgrass nutrition, potentially improving nutrient management strategies.

📄 Read the full study: https://doi.org/10.2135/cropsci2018.11.0706
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#TurfgrassScience #SoilTesting #GolfCourseManagement #TurfNutrition

Moore, D.B., Guillard, K., Geng, X., Morris, T.F. and Brinton, W.F. (2019), Predicting Cool-Season Turfgrass Response with Solvita Soil Tests, Part 1...

In this video, I dive into the fascinating world of turfgrass epistemology by analyzing emails, comments, Twitter discussions, and soil reports. How do these sources shape our understanding of turf science? What insights (or misinformation) can we uncover? Join me as we explore the intersection of communication, scientific reports, and the ever-evolving landscape of turfgrass knowledge.

📩 Drop your thoughts in the comments!
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