USGA Update

“Offense Sells Tickets, But Defense Wins Championships.” Bear Bryant By Adam Moeller, agronomist, Northeast Region
July 23, 2013

This putting green was syringed about 30 to 45 minutes too late because the golf course was very busy with play. This severe wilt damage is a clear example of the limitations with annual bluegrass putting greens in the summer.

Golf courses maintenance staffs throughout the region have been on high alert over the past two weeks because of extreme heat and oppressive humidity. The dew point remained above 73°F, heat indices exceeded 110°F, and soil temperatures were over 95°F for several days last week. To put things into perspective, cool-season turfgrass grass roots begin to decline when soil temperatures exceed 80°F, let alone 95°F. The recent environmental stress has resulted in grass decline at many golf facilities in the region, particularly on putting greens with limited air movement, shade, and/or poor soils. Heavily trafficked fairways have also experienced problems. Decline has been most severe on golf courses with high amounts of stress-intolerant annual bluegrass (i.e., Poa annua) and those with irrigation limitations (e.g., old systems and/or insufficient labor to hand-water and syringe). Damage observed has been as minimal as slight discoloration (i.e., yellowing) and minor thinning to severe grass loss requiring temporary putting greens.
Many facilities have held up well to the extreme heat by employing defensive management programs geared to keep grass alive. Defensive management programs are all about promoting healthy grass and alleviating stress; with less emphasis on maximizing playing conditions. When the weather is severe, even the most highly regarded golf facilities must back off and temporarily lower expectations for golf conditions to preserve grass health. The article Playing Defense is a Strength, Not a Weakness provides useful information on defensive management practices.
A key reason why many facilities have held up well to the heat is because they’ve previously addressed concerns with limited air movement, shade and tree root competition. Tree removals to improve sunlight and the use of oscillating fans to generate air movement are very helpful to improve grass performance so it can survive environmental stress. The Green Section Record articles Man’s Friend or Golf’s Enemy and Using Turf Fans in the Northeast are good references for examining putting green microclimates.
The environmental stress and subsequent decline of annual bluegrass putting greens has inspired many facilities to begin discussing the potential for regrassing to creeping bentgrass. Regrassing is not a simple project and improvements to the golf course infrastructure (i.e., increasing sunlight, improving drainage and addressing traffic concerns) are needed for creeping bentgrass to be successful, but the results will be well worth the effort. The Green Section Record articles Putting Green Regrassing and So Much More and Regrassing Greens at New Haven Country Club are great resources for facilities considering putting green regrassing.