Turfgrass Epistemology

In this episode of Turfgrass Epistemology, we examine Stanley Milgram's classic paper, Behavioral Study of Obedience (1963), and explore how authority influences our beliefs and decisions. Why do turf managers, consultants, and consumers often accept claims because a professor, university, or industry expert said them? Learn how the logical fallacy of Appeal to Authority can lead us to substitute...

In this episode of Turfgrass Epistemology, we examine one of the most influential scientific papers ever published: Judgment Under Uncertainty: Heuristics and Biases by Amos Tversky and Daniel Kahneman (1974). This landmark article introduced the concepts of representativeness, availability heuristics, and anchoring—mental shortcuts that help us make decisions but can also lead to systematic error...

Why do smart people search for evidence that confirms their beliefs instead of trying to prove themselves wrong? In this video, we explore Peter Wason's famous 2-4-6 experiment and the origins of confirmation bias. Paper: On the Failure to Eliminate Hypotheses in a Conceptual Task (1960) Author: P. C. Wason #ConfirmationBias #CriticalThinking #Psychology #DecisionMaking #ScientificThinking #Wason2...

Why do generic soil reports feel surprisingly accurate? In this video, we explore the Forer Effect and discuss how vague, universally true statements can create the illusion of personalized insight—whether in personality tests, astrology, or soil analysis. Paper: The Fallacy of Personal Validation: A Classroom Demonstration of Gullibility (1949) Author: Bertram R. Forer #ForerEffect #BarnumEffect...

Why do people conform to group pressure even when they know the group is wrong? In this video, we explore Solomon Asch's landmark conformity study, Opinions and Social Pressure (1955), and reveal what his famous experiments teach us about social influence, peer pressure, independent thinking, and human psychology. Paper: Opinions and Social Pressure (1955) Author: Solomon E. Asch #Psychology #Conf...

Does summer nitrogen really make brown patch worse in tall fescue? In this interview, Dr. Jada Powlen discusses her 2024 study and explains why cultivar selection may be more important than nitrogen rate for managing brown patch disease. Paper: Brown patch severity of five tall fescue cultivars as influenced by summer nitrogen rates (2024) Authors: Jada S. Powlen, James P. Kerns, Michael A. Fidanz...

In this video, I break down the classic study “Optimizing Manganese Fertilization for the Suppression of Take-All Patch Disease on Creeping Bentgrass.” We examine whether manganese applications can suppress take-all patch, how application timing influences disease control, and why soil chemistry matters. The results showed that manganese fertilization significantly reduced take-all patch severity,...

In this video, I break down the study “Evaluation of Calcium Silicate for Brown Patch and Dollar Spot Suppression on Turfgrasses.” We examine whether calcium silicate (Si fertilizers) actually suppress turfgrass diseases like brown patch and dollar spot. The results show that calcium silicate did not reduce dollar spot and, in some cases, actually increased brown patch severity, likely due to nutr...

In this video, I break down the research on biological and oil-based fungicides for dollar spot control in turfgrass. We examine whether products like biological fungicides, mineral oils, and plant-based treatments actually work compared to traditional chemistry. The results show that most biological products failed to provide consistent, season-long dollar spot control, while some oil-based produ...

In this video, I break down a lawn care discussion on nitrogen fertilizers and turfgrass performance, separating what’s scientifically sound from what may be oversimplified. We take a closer look at how nitrogen source, timing, and application strategy actually influence turfgrass growth—and whether the claims being made hold up under turfgrass science and soil fertility principles. If you're tryi...

In this video, I break down the “DirtBooster Organic Lawn and Garden Treatment” video from How to With Doc and take a closer look at the claims around soil microbes, biochar, humic substances, and “super compost.” The product is promoted as a way to rapidly build soil biology using ingredients like biochar, molasses, and microbial additives, but does the science support the idea that this translat...

In this video, I break down a popular lawn care video on soil testing, pH, and nutrient recommendations and separate what’s useful from what may be misleading. We take a closer look at how soil test results are interpreted, whether the recommendations actually make sense, and how to approach fertility decisions using evidence-based turfgrass science. If you're trying to better understand soil test...

In this video, I break down a lawn care video making the rounds online and separate what sounds right from what’s actually supported by turfgrass science. We take a closer look at the claims, the reasoning behind them, and whether they hold up when you apply basic principles of soil science and plant physiology. If you're trying to cut through the noise in lawn care advice, turfgrass management, a...

In this video, I respond to comments and emails and answer a common question: Why do dog urine (pet) spots last so long in turfgrass? We break down the science behind nitrogen burn, salt injury, and recovery limitations in lawns. If you’ve ever struggled with dog spots, lawn damage, or uneven turf recovery, this episode will help you understand what’s really happening—and what actually works. #tur...

In this episode, I sit down with Rob from Turf Therapy and Cam from Elevated Lawnscapes to talk all things lawn care, content creation, and turfgrass management. We discuss their approach to building great lawns, lessons learned on YouTube, and how they balance real-world lawn care with online advice. This is a great conversation for anyone interested in DIY lawn care, turfgrass tips, and the grow...

In this video, I break down the study “Influence of Calcium and Nitrogen Fertilizer on Creeping Bentgrass Infected with Dollar Spot.” We examine whether  it is calcium or lime that actually suppresses dollar spot, how it compares to nitrogen, and what happens when the two are applied together. The results show that both calcium and nitrogen reduced disease individually, but combining them was less...

In this video, I break down the classic study “Microbial Populations and Suppression of Dollar Spot Disease in Creeping Bentgrass with Inorganic and Organic Amendments.” We take a close look at whether organic fertilizers actually suppress dollar spot and how they influence microbial populations in turfgrass systems. The results show that while some organic amendments increased microbial activity,...

In this episode, I interview Dr. Scott McElroy (Auburn University) about weed control in turfgrass, including best practices for herbicide timing, resistance management, and how herbicides interact with insecticides. We also discuss common mistakes, application strategies, and where to find reliable, evidence-based recommendations. If you manage turf, this conversation will help you improve your w...

In this video, I break down a Floratine Masterclass where Tim Cartwright discusses a common claim about calcium availability in soils. I examine the argument, the science behind calcium in turfgrass soils, and whether the explanation actually aligns with what we know from soil chemistry and turfgrass research. If you manage turfgrass or are interested in soil testing, calcium availability, base sa...

In this video, I break down the research article “Soil Amendments and Fertilizer Source Effects on Creeping Bentgrass Establishment, Soil Microbial Activity, Thatch, and Disease.” We examine whether organic fertilizers, poultry meal, and humate soil amendments really improve bentgrass establishment, microbial activity, disease suppression, and thatch management on sand-based greens. The results sh...

In this video, I review the classic turfgrass study “Dollar Spot Severity, Tissue Nitrogen, and Soil Microbial Activity in Bentgrass as Influenced by Nitrogen Source.” We take a close look at whether organic fertilizers really suppress dollar spot and whether soil microbial activity plays the role many people claim. The results may surprise you. The study found that disease suppression was more cl...

In this video, I review the research article “Strategies for Increasing Ferrous Sulfate Efficacy Against Dollar Spot of Creeping Bentgrass.” We examine how ferrous sulfate (FeSO₄) can suppress dollar spot, how application techniques affect performance, and whether combining it with chlorothalonil improves disease control. The study found that nozzle selection and application strategy influence per...

In this episode of Turfgrass Epistemology, I critically examine the article “Exploratory Study on the Foliar Incorporation and Stability of Isotopically Labeled Amino Acids Applied to Turfgrass” (Agronomy, 2020) and use it as a case study in how “science” can be used to persuade without truly informing. On the surface, this paper uses isotopic labeling to show that foliar-applied glutamate can be...

In this episode of Turfgrass Epistemology, I break down the peer-reviewed Crop Science article “Mowing Strategies and Dew Removal to Minimize Dollar Spot on Creeping Bentgrass” by Ellram, Horgan, and Hulke (2007). This study evaluates how mowing time, dew removal frequency, blade sharpness, and leaf wetness duration (LWD) influence dollar spot severity on creeping bentgrass fairways. I explain why...

In this episode of Turfgrass Epistemology, I discuss the Purdue Extension publication “Common Diseases on Cool-Season Lawns” (BP-218-W), a practical guide to identifying and managing diseases on Kentucky bluegrass and tall fescue. This publication outlines major lawn diseases including dollar spot, brown patch, Pythium blight, red thread, rust, summer patch, gray leaf spot, and leaf spot/melting o...