How Does Summer Heat Stress Affect My Game?

Article By USGA Green Section

Regardless of the weather, superintendents frequently are asked to push putting green turf to its limit to meet player expectations. Superintendents face a real dilemma during hot summer weather: continue pushing for fast green speeds and risk turf damage, or err on the side of safety by raising mowing heights and risk complaints about slower green speeds. Superintendents walk a fine line between these choices in an effort to provide quality summer playing conditions. However, when conditions dictate, they must be prepared to make adjustments that protect long-term health and playability of the putting greens.

One adjustment superintendents make to protect the putting greens during hot weather is raising the mowing height. Mowing at low heights is a common practice to achieve fast green speeds. Unfortunately, low mowing heights also leave very little leaf area available for photosynthesis. During periods of hot weather, turfgrass that is mown extremely low will struggle to produce enough energy and can quickly decline.

Furthermore, ultralow mowing heights during hot weather makes turf vulnerable to disease and reduces its ability to tolerate other stresses such as insects, traffic, drought, shade and poor drainage. As a result, there is a serious risk of turf loss, which can lead to bumpy playing conditions and lost revenue. At minimum, extra resources will be needed to maintain acceptable putting green quality when heat-stressed turf is mown extremely low.

Golfers can help keep putting greens healthy and smooth during hot weather by being patient with temporarily slower green speeds. A well-timed, conservative decision to raise the mowing height could be the difference between healthy and dead putting greens.

Next time you see a superintendent checking putting greens on an extremely hot afternoon, be sure to express interest and understanding in the steps that are being taken to protect the putting greens from summer heat stress. Working together is the best way to protect a golf course.