LDS not LSD

No you're not hallucinating there is something funky on the greens. Sometimes with the heat (and usually after an aeration) the greens can develop dinner plate sized spots which can sometimes coalesce into a nice paisley patterns that cover large areas. The spots are a result of the turf being water stressed and are called Localized Dry Spots (LDS). There is multiple reasons why these occur including too much thatch, soil compaction, steep slopes, insects, disease, and the obvious one, poor irrigation coverage. Also, a sandy root zone that has accumulated enough organic molecules on a number of sand particles can eventually reach a point where the moisture content is so low that the growth media change from wettable to non-wettable resulting in the eventual turf decline.

LDS spot at the T-handle

End of the Soil Probe

Within LDS the sand is powder dry. I took two plugs, one from a LDS and one directly next a LDS to demonstrate.

Plug with Adequate Moisture

Versus Plug from LDS

We deal with these spots in a couple of ways. First, we spike the green surface to help break the surface tension that develops over the LDS. The equipment we use is nothing more than a series of "ninja throwing stars" lined up on a shaft which rotates as we pull it over the green.

Spiker Kit

The holes created are about one inch deep and hardly disrupt the surface.

Spiking Aftermath

To take full advantage of the perforations in the green surface the second thing we do is spray a class of product called a wetting agent. This product also has the characteristic of decreasing water surface tension as well as acting as a surfactant that allows the interaction of the dipolar water molecules with non-polar organic molecules coating some sand particles with the end result of making the once hydrophobic sand particle hydrophilic.

Usually, we can get a few months between treatments but a lot of that has to do with the weather (as usual) and how dry we let the greens get in between watering cycles. The easy thing to do would be to never shut the water off on the greens but that makes for some squishy greens so if it heats up more and we keep the greens dry you may see these spots before you eyes again before the season is up.