I explain that moving from full sun to tree shade reduced photosynthetically active radiation by about 80%. I show an app, and a PACE Turf document, that will allow you to find both PPFD and DLI no matter where you are located. I discussed these links: - https://www.asianturfgrass.com/post/shade-and-sun/ - https://asianturfgrass.shinyapps.io/ppfd_by_time/ - https://www.paceturf.org/memberedition/weather - https://www.paceturf.org/gallery/detail/photosynthetically-active-radiation - https://www.a...
Jun 23, 2025•37 min•Ep. 176
John Petrovsky is manager of USGA Green Section Education. He is also the host of the USGA Green Section podcast. We discussed a recent episode about GvX that had an especially insightful quote from Chris Tritabaugh. Also, the U.S. Open, championship golf, clipping volume, and even a bit about MLSN. Links for topics we discussed include: USGA Green Section Record free subscription https://www.usga.org/content/usga/home-page/course-care/green_section_record.htm the golf course shown with the Eiff...
Jun 18, 2025•1 hr 16 min•Ep. 175
Geoff Fenn and I discussed the use of the turfgrass growth potential (GP) in the UK, optimum temperatures, the GvX, clipping volume, and more in this episode that started with a look at this blog post: https://www.asianturfgrass.com/post/number-between-1-0-using-the-turfgrass-growth-potential/ See also this on GP and adjustments: https://www.asianturfgrass.com/post/regarding-gp-and-adjustments/ All posts tagged "growth potential:" https://www.asianturfgrass.com/tag/growth-potential/ Connect with...
Jun 09, 2025•54 min•Ep. 174
I discussed some green speed and green firmness data from measurements made at the Sky RKB Ladies Classic tournament, and I explained why the geometric mean rather than the arithmetic mean can be especially useful (and safe) when dealing with soil nutrient data. Green speed change from morning to afternoon: https://www.asianturfgrass.com/post/speed-drop-morning-to-afternoon/ The geometric mean as the central tendency (average) for soil nutrient data: https://www.asianturfgrass.com/post/geometric...
May 28, 2025•41 min•Ep. 173
In this episode I picked some of my favorite photos from 2024, and I remembered what I learned from them. From roots, layers, OM246, zoysia greens, and drought, to loupes, turf farms, compost, and bermudagrass. I discussed this post: https://www.asianturfgrass.com/post/flights-favorite-turf-photos-2024/ Here's the sand vs. compost ball bounce video: https://www.youtube.com/watch?v=r1LV77z_Ziw Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Find a suite of decisio...
May 11, 2025•44 min•Ep. 172
There have been a lot of conversations about soil water content and surface hardness (firmness). I discuss some measurements that I have made, and suggest some of the old posts on the ATC website that discuss this topic. Specific posts discussed include: https://www.asianturfgrass.com/post/measuring-surface-hardness-on-greens-fairways-and-approaches/ https://www.asianturfgrass.com/post/relationship-between-soil-water-and-turfgrass-surface-hardness/ https://www.asianturfgrass.com/tag/surface-hard...
May 01, 2025•16 min•Ep. 171
Jason came up with the GvX idea in a flash of inspiration that he describes here. This is the actual growth of the grass compared to the expected growth of the grass, and it has surprising practical implications. We discussed the development and use of the #TurfGvX in this episode. We discussed this blog post: https://www.asianturfgrass.com/post/explaining-gvx/ See the GvX screencast video at https://youtu.be/mRJcEhOyxPA Read more about all kinds of turfgrass topics at https://www.asianturfgrass...
Apr 25, 2025•34 min•Ep. 170
Achieving the lowest possible #OM246 total organic material value is not desirable, because the living plant material is part of the OM measured with this method. I discussed this post: https://www.asianturfgrass.com/post/om246-measures-living-om-too/ @keyakeeper469 and I discussed 8 years of OM246 in https://youtu.be/8B3FQhvSIdI OM246 project page https://www.asianturfgrass.com/project/om246/ Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Find a suite of decisi...
Apr 23, 2025•18 min•Ep. 169
A common way to calculate average daily temperature is to take the sum of the daily maximum and daily minimum temperatures, and to divide by two. A better statistical approximation of the average temperature is to take measurements made every hour and then to find the mean value of those continuous measurements. This blog post shows a comparison of the three methods for 2024 data at three locations: https://www.asianturfgrass.com/post/calculating-average-daily-temperature/ Read more about all ki...
Apr 17, 2025•18 min•Ep. 168
Joe Gulotti joined me to discuss his new job, The Talking Greenkeeper, and the ten posts on the ATC website that no one (practically) read in 2024. This is the post that lists all the "bombs:" https://www.asianturfgrass.com/post/ten-posts-no-one-read-2024/ The Talking Greenkeeper catalog is at https://podcasts.apple.com/us/podcast/the-talking-greenkeeper/id1435947281 Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Find a suite of decision-making tools at https://...
Mar 30, 2025•1 hr 34 min•Ep. 167
Although turf research is often done with fertilizer treatments applied at constant rates and on a fixed calendar schedule, that way of supplying nutrients seems strange to me now. I explain why in this episode, and suggest a better method. We discussed this post: https://www.asianturfgrass.com/post/fertilizer-schedule-seems-strange-to-me-now/ Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsletters at https://www.asianturfgrass.com/newsletter/ Turfgra...
Mar 17, 2025•22 min•Ep. 166
I recommend 4 podcast episodes and one useful app that calculates sand topdressing amounts, then quickly discuss the top 10 new posts from the ATC website in 2024. Would you like to comment or have questions about this episode? Reply on Bluesky Here are topic links: - https://www.asianturfgrass.com/post/top-10-posts-2024/ - https://www.asianturfgrass.com/post/the-rodney-lingle-system/ - https://www.asianturfgrass.com/post/almost-like-a-seminar/ - https://www.asianturfgrass.com/post/the-talking-g...
Mar 06, 2025•31 min•Ep. 165
Green speed varies because of many factors. One of those factors is clipping volume. I discuss that relationship and give some advice for those getting started with clipping volume and wanting to know how to adjust it. We discussed this blog post: https://www.asianturfgrass.com/post/getting-started-with-clipping-volume/ Potassium increases dollar spot? https://www.paceturf.org/memberedition/potassium-increases-dollar-spot The 2025 International Turfgrass Research Conference: https://itrc2025.tur...
Feb 21, 2025•33 min•Ep. 164
Did you know there was a time when up to to 2 lbs N per 1000 square feet per growing month, the equivalent of 100 kg of actual N per ha per month, was a standard recommendation for putting green turf? I talk about this and some implications in this episode. The ATC post getting the double cut treatment is https://www.asianturfgrass.com/post/nitrogen-rate-as-a-pendulum-swing/ I also took a look at the Historical Nitrogen Rates post from PACE Turf at https://www.paceturf.org/memberedition/historic...
Jan 29, 2025•31 min•Ep. 163
Bill Kreuser from GreenKeeper joined me to discuss how much grass grows, the complicated problems involved when sand is mixed with clippings, growth regulator adjustments, leaf nutrient content, soil surfactant effect duration, and more. #ClipVol We discussed the "Sand in clippings" post from the ATC website: https://www.asianturfgrass.com/post/sand-in-clippings/ You can read more about our discussion of topics such as PGR and soil surfactant scheduling at https://www.greenkeeperapp.com/ Read mo...
Dec 10, 2024•54 min•Ep. 162
Frank Rossi, Ph.D. is the New York State extension turfgrass specialist at Cornell University. We talked about mentorship, potassium, turf nutrition, smoothness of putting greens, dogma, data, budgets, and more. Here are some links: - https://cals.cornell.edu/frank-s-rossi - New podcast, Turf Without Borders: https://turfwb.asianturfgrass.com/episodes/st-andrews-old-new-jubilee-with-jon-wood - https://doublecut.asianturfgrass.com/episodes/frank-rossi-and-i-discuss-what-ive-called-my-least-favori...
Dec 04, 2024•1 hr 5 min•Ep. 161
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 depending on whether you are making the calculation for cool-season grass, warm-season grass, and on whether you are using the Fahrenheit temperature scal...
Nov 25, 2024•25 min•Ep. 160
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-example/ Subscribe to the Turf Without Borders podcast: https://turfwb.asianturfgrass.com/subscribe Read more about all kinds of turfgrass topics at htt...
Nov 12, 2024•22 min•Ep. 159
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/converting-clipping-volume-to-dry-weight/ Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsletters at htt...
Nov 03, 2024•20 min•Ep. 158
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 cloud with all the most frequent tagged topics, go to: https://www.asianturfgrass.com/#tags I've spoken about browntop bentgrass management in New...
Oct 30, 2024•1 hr 8 min•Ep. 157
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/ Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsletters at https://www.asianturfgrass.com/newsletter/ Tu...
Oct 25, 2024•21 min•Ep. 156
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 newsletters at https://www.asianturfgrass.com/newsletter/ Turfgrass information and decision-making tools at https://www.paceturf.org/ PACE Turf YouTube ch...
Oct 22, 2024•26 min•Ep. 155
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: - https://www.usga.org/content/usga/home-page/course-care/green-section-record/61/issue-15/measuring-and-comparing-the-water-requirements-of-warm-seaso...
Oct 18, 2024•1 hr 27 min•Ep. 154
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-contributions/ https://www.asianturfgrass.com/post/football-seminar-in-bangkok/ https://www.asianturfgrass.com/post/top-atc2x-episodes/ Read more abo...
Oct 16, 2024•24 min•Ep. 153
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 turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsletters at https://www.asianturfgrass.com/newsletter/ Turfgrass information and decision-mak...
Sep 30, 2024•28 min•Ep. 152
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 model produce an audio summary of that book. Blog post: https://www.asianturfgrass.com/post/grammar-greenkeeping-turfgrass-growth-optimal-playing-sur...
Sep 23, 2024•31 min•Ep. 151
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.asianturfgrass.com/post/accumulation-soil-organic-material/ https://hamiltongcmaintenance.blogspot.com/2018/06/poa-vs-browntop.html A "Cart Rides with Mi...
Sep 22, 2024•1 hr 40 min•Ep. 150
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-matter/ The Shiny app to calculate the accumulation rate is: https://asianturfgrass.shinyapps.io/om246/ You can learn all about OM246 tests at https://ww...
Sep 13, 2024•38 min•Ep. 149
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 green speed and smoothness annual summary in this post, discussed at the end of our podcast: https://ovgrounds.substack.com/p/chasing-the-numbers-2024-g...
Sep 02, 2024•43 min•Ep. 148
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-greenkeeper/id1435947281 Read more about all kinds of turfgrass topics at https://www.asianturfgrass.com/ Get ATC newsletters at https://www.asiantur...
Aug 30, 2024•53 min•Ep. 147
