The PACE Turf growth potential equation has one variable (the actual air temperature) and two constants. The constants are optimum air temperature and a term for variance that controls the shape of the curve as the actual temperature moves away from the optimum temperature. It's a little more complicated than that, because the constants change depe…

You can expect soil organic matter to be 5% nitrogen, and you can expect from 1 to 4% of that organic nitrogen to mineralize in one year. You can also calculate estimated daily mineralization and sum it to get weekly, monthly, and annual totals. The blog post discussed is: https://www.asianturfgrass.com/post/estimating-nitrogen-mineralization-an-ex…

This episode introduces multiple experiments that have demonstrated a link between rapid measurement of clipping volume and the clipping yield. Clipping yield is typically expressed as dry weight per area. Links to the articles discussed are in the blog post. Blog post on Converting Clipping Volume to Dry Weight: https://www.asianturfgrass.com/post…

Leah Brilman, Ph.D., is the Director of Product Management & Technical Services for Seed Research by DLF. We discussed velvet bentgrass, creeping bentgrass, and browntop bentgrass, along with seed production and grass performance. The bentgrass posts at the ATC website are at this link: https://www.asianturfgrass.com/tag/bentgrass/ To see the word …

Andrew McDaniel has been watching webinars to get education points, and some of these have been about management of soil organic matter on putting greens. We discussed a particular article and whether that method is something that seems reasonable today. The blog post we discussed is https://www.asianturfgrass.com/post/a-chance-to-update-my-advice/…

Here are four specific things to look at with total organic material by depth (#OM246) test results. The blog post I discussed is this one: https://www.asianturfgrass.com/post/om246-reports-explained/ The video in that post is https://youtu.be/wUtpJC1YPU0 Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsl…

Matteo Serena is the Senior Manager of Irrigation Research and Services for the USGA. We discussed drip irrigation, growth regulators and soil surfactants, water use, overseeding, and bermudagrass vs. zoysiagrass water use. We discussed this ATC blog post: https://www.asianturfgrass.com/post/zoysia-and-water-use/ We also discussed these articles: -…

I checked the top episodes, discussed turf terminology, and discussed the 2025 GCSAA Outstanding Contribution Award winners Dr. Wendy Gelernter and Dr. Larry Stowell. The four posts discussed in this episode are: https://www.asianturfgrass.com/post/the-turf-gvx-growth-versus-expected/ https://www.asianturfgrass.com/post/seven-minutes-of-outstanding…

When the cool-season growth potential (GP) is lower than the warm-season GP, the difference between them (the ΔGP) will be negative. In this episode, I discuss ΔGP and three different ways to think of summer duration. I discussed this blog post: https://www.asianturfgrass.com/post/summer-assessment-with-delta-gp/ Read more about all kinds of turfgr…

I wondered what NotebookLM could do, so I created a couple notebooks. One has the title “Global Soil Survey,” and in that notebook I uploaded articles and documents I’ve written about MLSN and the GSS. I let the model generate a few different audio summaries of this project. And I uploaded the text to A Short Grammar of Greenkeeping, and I let the …

Grant Saunders is the course superintendent at Hamilton Golf Club in New Zealand. He has successfully overseen a green species conversion from Poa annua to browntop bentgrass (Agrostis capillaris). We discussed that, and the role of OM testing, and sand topdressing, and soil pH, and greenkeeping in New Zealand. Some links include: https://www.asian…

When you know the rate at which organic material is accumulating in the rootzone, you can adjust sand topdressing rates with more precision. You can also start to check how any changes in maintenance can have an effect on the accumulation rate. The blog post discussed is this one: https://www.asianturfgrass.com/post/inexorable-rise-soil-organic-mat…

T-Jay Creamer is the golf course superintendent at Olympic View Golf Club in western Canada. He joined me to discuss tournament golf maintenance and the grammar of greenkeeping. We discussed this ATC blog post: https://www.asianturfgrass.com/post/two-weeks-in-august/ T-Jay's Substack newsletter is https://ovgrounds.substack.com/ He explained the gr…

A month ago Joe Gulotti and I walked the fairways and greens of the Montchanin Course at Dupont Country Club. I wrote a blog post about that, and we discussed my visit in this episode. Blog post: https://www.asianturfgrass.com/post/a-visit-to-the-talking-greenkeeper/ The Talking Greenkeeper podcast: https://podcasts.apple.com/us/podcast/the-talking…

You can sometimes, perhaps more often than you would think, find soil under good turf to have lower nutrient content than does soil under poor quality turf. In this episode, I explain why that is, what the implications of this phenomenon are, and what you can do about it. This blog post has all the details on the turf (and soil) paradox: https://ww…

Independent turfgrass researcher John Dempsey, Ph.D., joined me to discuss evaluating treatment effects and the importance of having a good control. We talked about diseases, nutrition, and this blog post: https://www.asianturfgrass.com/post/problem-with-the-controls/ Find John on X at https://x.com/J_J_Dempsey Read more about all kinds of turfgras…

Dr. Henry Qu, partner and data scientist at Oxbridge Economics, joined me to talk about data analysis, and statistics, and how to try to learn things in turfgrass science. We discussed NTEP, posterior distributions, disease resistance, ANOVA, total organic material expectations by species, the process of learning, and much more. ATC blog post about…

Jon Wall, golf course superintendent at Shanqin Bay, joined me to discuss doing more work to make grass better, rather than doing less. And also about what I'd want everyone to do, which is doing the right amount of work for your property. We talked about many things, starting off with: Better turf conditions with more intensive maintenance blog po…

It's summer in the northern hemisphere, and the two items discussed in this episode provide guidance on managing turf when it has to survive through heat stress. From the ATC website, a 12 point list: https://www.asianturfgrass.com/post/catching-up-on-reading-heat-stress/ From PACE Turf, the Heat Kills document: https://www.paceturf.org/member/Docu…

Carl Schimenti from Cornell University joined me to discuss intro to #MLSN explanations vs. using MLSN the way it is designed to be used. We also talked a lot about ball roll assessment using the #BobbleTest, and the USGA GS3 ball, and other methods. MLSN project page: https://www.asianturfgrass.com/mlsn/ Daniel Palin with the MLSN test on The Talk…

Soil P, pH, and salinity are a few things that likely vary by depth in your rootzone. I've started recommending that 20% of putting greens tested be done with a sample divided at the 5 cm depth. Send the lab a 0-5 cm and 5-10 cm depth sample from that green, rather than the standard 0-10 cm depth sample. I discussed this blog post: https://www.asia…

Maggie Reiter joined me to discuss how the start (and end) of the turfgrass maintenance season might be predicted. When is spring green-up? When does the season end? We discussed, and showed charts of growth potential and temperature, from this post: https://www.asianturfgrass.com/post/maps-of-average-temperatures-in-the-usa/ The Sunday Lawn Care p…

Bill Kreuser, Ph.D., president of GreenKeeper, joined me to discuss the new water resource planning tools in GreenKeeper, along with disease risk, PGRs, soil surfactants, and weather data. See more about these tools at the GreenKeeper app: https://www.greenkeeperapp.com/ Irrigation posts at the ATC website: https://www.asianturfgrass.com/tag/irriga…

I discuss small plot university research with fixed treatments vs. golf course and sports turf maintenance with treatments that vary, and consider which results we should trust more. I also discuss the bobble test after 270 rounds, mention that core sweepers are a nice machine, and explain how I estimate N harvested in creeping bentgrass clippings.…

I describe what we can learn from looking at five years of Mehlich 3 soil test phosphorus results from golf course putting greens, how to calculate the turfgrass speedo in a standard way, rather than in a chaotic way, and recommend an episode of the Cornell Turfgrass Show that asks if soil testing is the answer to all your problems. These are the l…

T-Jay Creamer joined me to discuss bentgrass & Poa annua (bent-Poa) management with a surprisingly low annual N rate, almost no use of PGRs, and no aeration (other than occasional needle tining) for more than two years. The results surprise me, and they may surprise you too. We discussed this blog post about the turf speedo: https://www.asianturfgr…

In this episode, I discuss sixteen year old bentgrass greens that have also gone sixteen years without P fertilizer. The greens are also free of Poa annua. Then I discuss how fertilizer recommendations made from soil tests are a lot more precise if the time duration over which the fertilizer is being recommended is considered explicitly. And I expl…

Jim Huntoon joined me from Horry-Georgetown Technical College to discuss overseeding and the hows and whys of this common practice on warm-season turf that goes dormant in winter. We discussed these two blog posts: - https://www.asianturfgrass.com/post/optimum-overseeding-time-windows/ - https://www.asianturfgrass.com/post/zoysia-beats-bermuda-on-s…

Maggie Reiter joined me to reminisce about the grasses one can find at the back of the 7th green at Pebble Beach Golf Links, to consider soil test results for lawns, what the biggest problems are on lawns and whether solutions exists, and much more. Maggie is a Data Scientist at Sunday, https://www.getsunday.com/ The blog post with the photo of gra…

This is a follow-up to the episode last week when I mentioned that I was looking at snow outside, that the light would be ample for growth, but the temperatures were below freezing and thus temperature was limiting the growth. I discuss the new blog post that shows those light data. An example of ample DLI: https://www.asianturfgrass.com/post/an-ex…

The growth potential converts air temperature to a 0 to 1 (or 0 to 100%) scale. Of course, there are a lot more things that affect actual growth, including light, nitrogen, and water. I discuss these and why I'm not so convinced that adding a light factor to GP makes it more useful. The blog post discussed here is https://www.asianturfgrass.com/pos…

This episode goes through a lot of updates from both the ATC and the PACE Turf websites. Topics discussed include OM246, the problem with frequent soil testing, the problem when getting soil tests done by some fertilizer companies, normal N content of grass leaves, and coefficient of uniformity (Cu) of rootzone sands. More information and and decis…

Adam Moeller joined me to discuss how to manage greens in 2024. We talked about his research at Purdue University on sand and bentgrass and coring and N rates, and about clipping volume and OM246 testing and how we might manage turf and look at sands today. This post got the Doublecut introduction, about how to figure out an estimate of N harvest f…

Brian joined me to discuss his recommended soil sampling strategy for an 18 hole golf course. We also discussed what he teaches in a 2 hour GCSAA seminar on physical testing. Mavis Consulting website with lots of resources: http://mavisconsulting.com/ This blog post on soil sampling got the Doublecut treatment: https://www.asianturfgrass.com/post/c…

The 2018 article by Bryan and Tyler Hopkins, "Carbon: the next frontier in fertilization?" concludes that we "should not be fertilizing with carbon." Bryan joined me to discuss this article. The blog post about their article remains one of the top viewed on the ATC website, six years after publication: https://www.asianturfgrass.com/post/is-carbon-…

Zoysiagrass can seed year round when the conditions are right. In this episode, I discuss what those conditions are, share some tools for getting a site-specific sand topdressing estimate, describe the reshuffling of top posts on the ATC website, and discuss using a line laser to measure the effective height of cut. I have also recently been the gu…

Joe Gulotti, The Talking Greenkeeper, joined me to discuss the ATC blog posts that received the fewest views in 2023. We give these topics one more chance, while talking about quality of ball roll, playability, fertilizer, surface firmness, seminars, translation, and much more. The blog post with these 10 blog post "bombs" is https://www.asianturfg…

With Google Analytics I can check the pages on the ATC website that get the most views. These were the ten posts from 2023 that got the most pageviews. These posts are listed, with direct links to each, at https://www.asianturfgrass.com/post/ten-posts-no-one-read-2023/ Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/…

I looked through my "Flights and favorite turf photos" post to see what I learned, or what I was reminded of, through these photos. I discuss N rate, grass species, dormancy, traffic, leaf area, crew size, Poa annua, pesticides, and a lot more. This is the post I discussed: https://www.asianturfgrass.com/post/flights-favorite-turf-photos-2023/ I me…

In 2018, I delivered four presentations/classes at the Continue to Learn education conference in Harrogate, England. Deb Burnett and Sami Strutt from BIGGA joined me to discuss how an education program gets put together and evaluated. The Doublecut post was: https://www.asianturfgrass.com/post/four-presentations-at-btme/ BIGGA website: https://www.…

Chris Tritabaugh joined me to discuss sand topdressing, a long-running conversation we've been having with Dr. John Kaminski, the quantities of sand and N that are recommended vs. the amounts that seem to be required in modern turf maintenance, and much more. We discussed this post from the ATC website about nitrogen, coring, and sand: https://www.…

Janne Lehto from Hirsala Golf joined me to discuss robotic automowers. Hirsala Golf currently has a fleet of 36 machines, mowing all fairways and 75% of the rough with these autonomous mowers. We discussed mowing heights, some of the interesting benefits that come with using these types of machines, and discussed a few drawbacks. Find Janne on Ints…

I talked about some recent blog posts, including updated #OM246 sampling instructions, there is no such thing as an MLSN nitrogen rate, soil samples cannot dry too much, and more. Links to these posts are: - https://www.asianturfgrass.com/post/mlsn-is-not-gp/ - PACE climate appraisal form https://www.paceturf.org/journal/climate - https://www.asian…

Can soil surfactant (wetting agent) applications be scheduled based on site temperatures? Can a growing degree day model work for this? Dr. Bill Kreuser, president of Greenkeeper, joined me to discuss his exciting progress with this research. - ATC blog post on what wetting agents really do: https://www.asianturfgrass.com/post/what-do-wetting-agent…

Lake Karrinyup Country Club in Perth, Western Australia has creeping bentgrass greens and sometimes sees high temperatures over 40 °C. Course superintendent Fraser Brown joined me to discuss how he and the maintenance team manage the grass in this year-round golfing climate. Find Fraser on X at https://twitter.com/FraserJBrown_ Read the ATM profile…

I spoke with Michael Bekken about normal nitrogen rates, why they vary so much, why that matters, what a normal N rate linked to growth potential (GP) might be, and greenhouse gas emissions from turfgrass maintenance. We talked about: - how to keep up with turf info from ATC and PACE Turf, https://www.asianturfgrass.com/post/whats-the-best-way-to-k…

Dr. Chas Schmid has been involved with many of the same topics I often study and consider---sand topdressing, potassium fertilization, soil organic matter, putting green performance, and so on. His data, and plenty of photographic evidence, also show that there can be completely different outcomes than what I might have expected. We discuss this, o…

This considers fertilizer programs, whether research can be misleading when fertilizer is applied at fixed rates on calendar schedules, and why I'm excited about the utility of the growth ratio. Blog posts discussed include: - https://www.asianturfgrass.com/post/already-proving-to-be-more-valuable-than-i-originally-expected/ - https://www.asianturf…

I was a co-author, in 2013, of an article with the title "Documenting your progress toward sustainability." Jon Wall joined me to discuss this topic, and to consider whether keeping track of annual totals of inputs and resource use in a few key areas can be a meaningful way to document sustainable land management practices in the golf industry. The…

I flipped through four recent blog posts, about zoysia seedheads on putting greens, the practical question of how much organic matter (or total organic material is too much), seminars in France, circle mows, and botanical walks to find grass growing in nature. Links to these posts are: https://www.asianturfgrass.com/post/seedheads-greens-height-zoy…