Stu Rowland, Director of Agronomy
Summertime in the Hill Country is upon us with the warm Southern breeze and the rain spigot seemingly turned off from the welcomed spring rains. The course has benefitted from those rains as course conditions have been excellent to start the summer. One area that we focus on during the summer is our bentgrass greens. Cordillera’s Pure Distinction bentgrass is a highlight of the Club’s golf experience and during the summer, it takes many tools and talents to keep them rolling nicely.
Bentgrass has historically been a grass that finds its home in regions where the climate is cooler than the Southern states. It is a C3 plant, meaning that it has adapted to cooler environments where it thrives in either wet or dry environments. Although we can see some wild swings in temperatures, our Pure Distinction bentgrass grows nearly all 52 weeks of the year, unlike Bermuda surfaces that have a period of dormancy in the winter. Bentgrass is also chosen for its fine-bladed texture and density. With a dense canopy of fine blades of turf, putting across the surface will be smoother and more consistent than C4 (warm season) turf grasses.
When summer arrives, bentgrass is more susceptible to both environmental and mechanical stresses. To address those stresses, we employ a few tools and strategies. First, mowing the greens every day and each green receiving 100 golfers or more walking all over creates a tremendous amount of stress. To alleviate that stress, we employ consistent topdressing and aeration of some kind each Monday to reduce compaction and allow the greens to breathe and recover. Summer aerification consists of smaller pencil-sized holes that have minimal impact on golf as well as the topdressing of a very light coat of sand. Unlike the spring and fall aerifications in which we disrupt the surfaces much more, our summer practices are lighter in an effort to achieve recovery and lower impact to play.
Secondly, and most importantly, is our irrigation and water management. As we like to say, “Water kills!” The task of monitoring moisture and deciding how much water is part science and part feel. Before the advent of monitoring devices (pictured), watering would happen more on dry days, less on humid days, and we’d poke a sample probe in the ground to see how wet or dry the soil was. Today, we use a device that measures the volumetric water content percentage of the soil under the turf. Depending on the forecasted temperature and humidity, we can be much more specific with our water amounts and locations of applied water as we typically measure 20-30 spots over each green. Still, this requires a skilled person with a water hose to apply the correct amount of water. Too much water on a hot humid day can essentially boil the grass, whereas the perfect amount keeps the grass with enough moisture to maintain temperature throughout the day.
Finally, our last tool is essential to keep air flowing over the surface to cool the plant. When you sweat, beads of water form on your skin and when you feel a breeze, your skin feels suddenly cool. The same is true with the fans we place around our greens (pictured). The fans keep constant airflow over the surface of the green and promote the evaporative cooling effect to the turf. Additionally, the fans keep the surfaces dry, reducing the potential for disease and surface algae from the increased watering during the summer. As an added benefit, the fans promote oxygen exchange with the soil as air constantly flows across the surface especially when we do our light venting aerifications.
Cordillera Ranch’s greens are the Southernmost in the USA that are bentgrass. The time, tools and team talents keep them thriving, even in the most stressful months of the year.
Stu Rowland is the Director of Agronomy at The Clubs of Cordillera Ranch. He can be reached at firstname.lastname@example.org and 760.275.9459