We’ve just received our latest organic matter (OM) test results from Penn State University, for a selected representation of South Course greens. In short, the results below show favorable support for our programs designed to reduce overall organic matter, also known as thatch. To quote from Dr. Andrew McNitt of Penn State University, “The organic matter has decreased in each green compared to September 2016 amounts. It is suggested that organic matter removal practices be continued in order to remove additional organic matter from the rootzone as Turfgrass plants constantly deposit organic matter.”
Our optimum goal for organic matter percentage is a close plus or minus 1%. However, even as we reach this goal, established thatch managements programs must remain a consistent part of our seasonal maintenance plan in order to keep the percentages at the optimal level.
To understand how these numbers translate into the playability of the course, especially the greens, we must first understand what organic matter (thatch) is and how it works. Thatch is a mixture of both living and dead grass stems, shoots and roots that build just under the surface of the turfgrass canopy. This constant formation of material occurs as the grass plants continually grow new root and leaf tissue and the old ones die off. Over an extended period of time, microbial activity will break this material down into new soil. Unfortunately, not at a pace needed to sustain quality putting surfaces. A small percentage, 1% to 2% of thatch accumulation is a benefit because it helps the turf hold together when golf balls are hit into it and holds just the right amount of moisture. As the percentages get higher, which means more thatch, the turf holds even more moisture. With softer conditions, the greens become more susceptible to damage from ball marks and foot traffic from golf spikes not to mention the putting surface becomes bumpier and bumpier.
As this process of thatch accumulation is constant, how can we effectively control organic matter (thatch)? There are two important strategies dedicated to managing it and its potential negative effects on playability:
1. Dilution- A combination of natural microbial breakdown and the addition of topdressing sand over the surface, working its way down into the thatch layer, allowing firmer and drier conditions.
2. Physical removal- Hollow tine core aeration during Spring and Fall.
When both are accomplished on a consistent basis, thatch can be effectively controlled. Club play, tournament calendars, and weather disruptions can make this a difficult task. We can achieve our Dilution goal with frequent lighter sand applications throughout the growing season that limit the disruption to putting quality, as a complement to our heavier applications during aeration. Aeration, although a bit more disruptive due to the length of recovery, is a necessary and important second half of the thatch management process. We make every effort to schedule this process at ideal growing times for the turfgrass in order to shorten the window for recovery and a return to normal playing conditions as soon as possible. As always, we strive to create the best playing conditions possible throughout the entire year. While some of our programs are more intrusive than others, all have a significant benefit to the short term and most importantly, long term quality of turf and playing conditions.