Insight · Insight
What a turf map can tell you
A color map on a laptop can be a genuine help to a short-handed crew, because it sometimes marks turf that is starting to go off before a person walking the same ground would score it that way. What it cannot do, and what USGA writing has been clear about for years, is name the cause.
Who is this post geared towards? GMs and owners who are sitting through a demo of a heat map, or reading a proposal that treats the camera as if it has already done the diagnosis.
Why would they care? The map can be useful. It can also be sold as something it is not. If the club treats the picture as the answer, people walk less, and the thin patch still does not have a name.
What should or could they do with this information? If you buy imagery, use it to decide where the crew should walk first. Keep the person who already knows the ground as the one who says whether that spot is dry, diseased, or just tired.
There is a meeting a lot of clubs are having this year. Someone opens a laptop, a color map of the course fills the screen, and the conversation tilts toward the idea that the camera has already found the trouble. The red or the yellow looks decisive. It is easy, sitting in that room, to feel that the walk just became optional.
A better question for a GM is quieter, and it does not require you to be a turf scientist. Does this picture name the cause, or does it only mark a place that still needs a person? Those are different jobs, and they have different prices attached.
Cory Isom, writing for the USGA Green Section in 2024, was generous about what aerial and thermal images can do. They can show that turf health or density is compromised. He then asked the question the demo often skips: how do you know the real problem from the image alone? Drought, disease, insects, shade, and traffic can all look like the same thin patch once they have been turned into a color. A USGA tip from 2019 said the same thing in more everyday language. Drones cannot currently tell drought, compaction, and disease apart, and the staff still have to get out and look.
None of that makes the map a toy. In 2019, Mu Hong’s thesis at Kansas State, funded by the USGA, found that drought readings on bentgrass plots moved a week or two before the eye would have scored the turf as off. That is a real result, and it is also plot work under a rainout shelter, not a Tuesday morning on an 18-hole property with members in the fairway. Lee Carr, writing in Golf Course Industry, put the practical limit in one useful sentence: maps can give an early warning, and the data does not solve problems on its own. Someone who already knows the turf still has to read it.
The closest public work we found that actually marks dollar spot in a photograph is a 2024 paper out of Virginia Tech, later recapped by CSA News. The model was accurate on still field images and ran in milliseconds on a research computer. That is interesting, and it is not a product hanging on a mower this winter. A club cannot buy that paper and skip the walk.
For a short-handed crew, a scheduled map can still earn its keep if it changes where people start. It can send the assistant to the three holes that actually look off, instead of the eighteen they already know by heart. What it cannot do is replace the person who crouches down, pulls a sample, and says what they are looking at. Isom’s line is the one that travels: there is no substitute for boots on the ground.
If you want to talk through what a map can and cannot do on an 18-hole operation, start a conversation.