You may have noticed that our greens are showing some signs of heat stress as we get into the hottest time of the year. Greens are not as smooth as several weeks ago because of the high heat and they do not recover as quickly from heavy golfer traffic. Temperatures in the 90's and above can be harmful to our A1/A4/G3 bentgrass greens and different management techniques are put in place during the summer to limit the adverse effects of high heat and humidity as much as possible. Here are some things we do to sustain the health of our greens during the summer months.
1. Spot Aerification
Some of our greens receive a light aerification on an "as needed" basis when temperatures rise. We recently performed spot aerification on greens 1 through 6 (many members have noticed and commented on this). Spot aerification is performed on the lowest areas of some of our greens where necessary to increase drainage and oxygen intake and thereby avoid heat damage to those areas.
2. Syringing of Greens
Golf course staff closely monitors green conditions during the day and "syringe" greens where necessary to reduce air temperature near the green surface. Syringing of greens is a process of lightly watering the green using a hand held hose and spraying a light shower of water upwards above the green. Contrary to popular belief, the purpose of syringing the greens is NOT to get more water on the grass. In fact, too much water on the greens in hot weather can be much more detrimental to their health than too little water. Hand syringing is performed to cool down the air temperature just above the surface of the green. USGA research has shown that lowering the air temperature by just a few degrees provides enormous benefit to the health of the grass leaf. Here is a USGA video with more information about the benefits of green syringing and the technique used to syringe the greens.
3. Increased Fertility
Heat stress decreases the ability of grass to photosynthesize: essentially, it can't make enough energy on its own to maintain healthy root growth. To offset this reduced photosynthesis, we increase fertility during hot summer months to provide induced energy for the grass. Think of this increased fertility as a "shot in the arm" to help the grass through a stressful period.
4. Change in Mowing Techniques
We change our greens mowing equipment in the summer months to provide a little relief to the grass compared to the more aggressive cutting equipment that we can use in the spring and fall without adverse impact on green health. There is a full description of the equipment used in summer along with comparative pictures in an article we published on June 26, 2011.
What do all the above changes in management techniques mean to the golfer? Mainly, it means that the greens will not be quite as smooth nor quite as speedy during the dog days of summer. Our main goal during the summer is to preserve the health of the greens so that they can survive until heat breaks in late summer or early fall. Once we reach cooler temperatures later this year, the greens should improve quickly and we will change our management practices again to provide the same great putting conditions we saw earlier this spring.
