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 saturation, and turfgrass fertility myths, this discussion will help you think critically about the claims often made in the industry.

#turfgrass #soilscience #calcium #soiltesting #turfmanagement #golfcoursemanagement #turfgrassepistemology 

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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 show that readily available nitrogen from synthetic fertilizers produced faster establishment and generally better turf quality, while organic programs increased microbial activity but did not improve establishment or consistently suppress disease.

If you manage golf greens, creeping bentgrass, or sand-based rootzones, this study provides important insights into fertilizer sources, soil amendments, microbial activity, and turfgrass disease management.

#turfgrass #bentgrass #golfcoursemanagement #turfgrassscience #fertilizer #soilscience #dollarspot

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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 closely related to nitrogen availability and turf growth than to microbial activity or organic fertilizer sources. 

If you manage bentgrass fairways or want evidence-based guidance on dollar spot management, nitrogen fertilization, and organic vs synthetic fertilizers, this paper is worth understanding.

#turfgrass #golfcoursemanagement #dollarspot #turfgrassscience #fertilizer #bentgrass #soilscience

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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 performance, and that ferrous sulfate can reduce the amount of chlorothalonil needed and extend its effectiveness against dollar spot. 

If you manage creeping bentgrass greens or fairways, this research provides valuable insights into dollar spot management, iron applications, and fungicide optimization.

#turfgrass #dollarspot #golfcoursemanagement #turfgrassscience #bentgrass #fungicides #soilscience

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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 absorbed and incorporated into creeping bentgrass metabolism. But in this video, I explain why the study’s publication in a predatory journal, its direct funding and involvement by one of the product’s commercial stakeholders, and its failure to follow essential agronomic methodology make it a weak foundation for product claims.

The paper does not measure turf performance, stress tolerance, growth response, or field-level outcomes—yet it is often cited to imply real-world biostimulant benefits. I walk through how mechanistic tracer data can be presented in a way that sounds rigorous while sidestepping the fundamental question: does this improve turf performance in meaningful, reproducible field conditions?

This episode is for golf course superintendents, turfgrass professionals, and lawn care managers who want to understand how conflicts of interest, journal quality, and experimental design influence the credibility of research. Not all published studies are equal—and learning to evaluate methodology is essential for evidence-based turfgrass management.

Subscribe for more deep dives into turfgrass research, critical analysis of industry claims, and discussions focused on how we know what we know.

#Turfgrass #SoilScience #LawnCare #GolfCourseManagement #TurfgrassScience #SoilFertility #CriticalThinking #TurfTok #TurfgrassEpistemology #EvidenceBased #LawnCareTips

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Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

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 mowing at 4:00 AM consistently reduced dollar spot compared to 10:00 AM, why daily dew removal outperformed alternate-day removal, and why dull mower blades did not increase disease despite common belief. The controlled-environment data also show lesion size increased dramatically as leaf wetness duration extended from 6 to 18 hours.

If you manage creeping bentgrass, battle dollar spot, or want to better understand the role of irrigation timing, dew removal, and cultural disease control, this video connects classic research to modern integrated pest management strategies.

Subscribe for more turfgrass disease management, dollar spot research, and evidence-based golf course agronomy discussions focused on how we know what we know.

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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 out, while also emphasizing the critical distinction between biotic diseases and abiotic disorders such as compaction, drought, and nutrient stress. I explain why accurate diagnosis requires understanding host species, environmental conditions, and disease spread patterns—not just visual symptoms.

If you manage cool-season lawns, advise homeowners, or work in turfgrass disease management, this video breaks down key takeaways from this guide and connects them to evidence-based lawn care practices.

Subscribe for more turfgrass disease management, lawn care science, and evidence-based turfgrass education focused on how we know what we know.

#Turfgrass #SoilScience #LawnCare #GolfCourseManagement #TurfgrassScience #SoilFertility #CriticalThinking #TurfTok #TurfgrassEpistemology #EvidenceBased #LawnCareTips

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Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

In this episode of Turfgrass Epistemology, I discuss the peer-reviewed article “Dollar Spot Resistance among Blends of Creeping Bentgrass Cultivars” by Abernathy et al. (2001), published in Crop Science.

This study evaluates whether blending creeping bentgrass cultivars can reduce dollar spot severity compared to monostands on golf course putting greens. I explain how highly susceptible cultivars like Crenshaw increased disease pressure in blends, how resistant cultivars like L-93 suppressed dollar spot, and why overall disease levels in blends often reflected a compromise between the resistance levels of the individual components.

The key takeaway: blending resistant and susceptible cultivars can significantly reduce dollar spot compared to planting a susceptible cultivar alone—but blends do not automatically create superior resistance across the board.

If you manage creeping bentgrass putting greens or make decisions about cultivar selection, genetic diversity, and dollar spot management, this video breaks down what the data actually show and how blending fits into an evidence-based disease management strategy.

Subscribe for more turfgrass science, cultivar performance research, and evidence-based golf course management discussions.

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In this episode of Turfgrass Epistemology, I break down the classic Crop Science paper “Assessing Irrigation Management for Its Effects on Disease and Weed Levels in Perennial Ryegrass” by Jiang, Fry, and Tisserat (1998).

This study directly examines how irrigation scheduling (daily vs. ET-based irrigation) influences brown patch, dollar spot, weed pressure, pesticide use, and turf quality on perennial ryegrass fairways. I explain how ET-based irrigation reduced water use by nearly 200%, how daily irrigation suppressed brown patch but increased dollar spot, and why irrigation strategy did not significantly influence crabgrass or dandelion populations.

If you manage golf course fairways or make decisions about irrigation management, turfgrass disease control, and water conservation, this video connects classic research to modern turf management and integrated pest management strategies.

Subscribe for more turfgrass science, irrigation research, and evidence-based golf course management discussions focused on how we know what we know.

#Turfgrass #SoilScience #LawnCare #GolfCourseManagement #TurfgrassScience #SoilFertility #CriticalThinking #TurfTok #TurfgrassEpistemology #EvidenceBased #LawnCareTips

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Diagnostic Criteria for Turfgrass Bullshit Disorder:https://drive.google.com/file/d/1Y_GeVPQ237pzm0ImTP4eVij6I9D0PHPn/view

In this episode of Turfgrass Epistemology – Comments & Emails Part 2, I continue responding to viewer questions and email discussions about turfgrass management, soil testing, fertilizer programs, dollar spot control, and common lawn care myths.

This follow-up video addresses new comments from golf course superintendents, lawn care operators, and homeowners who are trying to separate evidence-based turfgrass science from marketing claims and social media advice. I clarify misunderstandings about nutrient ratios, iron applications, nitrogen programs, and disease suppression while explaining how to interpret research correctly.

If you’re interested in soil fertility, turfgrass disease management, golf course agronomy, or lawn care best practices, this episode provides practical, research-driven answers to real questions from the field.

Subscribe for more turfgrass science, critical thinking in lawn care, and evidence-based golf course management discussions that go deeper than quick tips and product hype.

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