" Why are our greens so slow. I heard they are only 9.5' on the Stimpmeter. I played at the Grass is Always Greener C.C. and they said their greens were running 12'. "

We try to maintain our green speed at 10' during the summer months. Any faster than 10' and we start to see putts rolling off steeper slopes on the greens. Fast greens are good until you start to see 3 and 4 putts. There are a few factors that determine how fast the greens putt. They are:

Height of Cut - The shorter the grass the quicker they roll.
Rolling Frequency - Rolling = speed.
Sand Top Dressing - Applying sand tightens up the turf canopy effectively making the grass shorter.
Fertility - Greens are faster with lower levels of fertility.
Weather - Dry weather & low humidity = fast, Rain & high humidity = slow.

The most important is height of cut. Our 18 hole greens are mowed at .118" height throughout the season. Every course has reasons for choosing their height of cut. Many Chicago area courses mow their greens higher and a few mow lower. We chose our height because we can insure the greens will be healthy and can recover from normal wear and tear.

The second most important factor is how often the greens are rolled. We roll the greens with a vibratory triplex roller. Each time we roll, the green speed increases 6". We normally roll 2 to 3 times per week often substituting rolling for mowing.

A vibratory roller smooths the green and increases Stimpmeter speed by 6".

This season it has been very difficult to find days when it is not too wet to roll. Rolling when the turf is too wet will cause the surface of the greens to compact. Once compacted, it is difficult for water nutrients and air to reach the turf's roots causing a rapid decline in quality. Rolling is also tough on the turf when temperatures are high. The turf on greens is under great stress in the summer heat. Rolling at the wrong time can cause a quick decline in plant health. The third factor that controls green speed is how often sand top dressing is applied.

A thin layer of sand is applied to greens to smooth the surface and reduce thatch build-up.

A light application of sand every 10 to 14 days keeps the greens rolling smooth and fast.

Sand top dressing is applied to greens every 10-14 days to control thatch build-up and to smooth the greens. We have only top dressed greens a few times this year because all the rainfall has made it difficult to find a window when conditions are dry enough to work the sand into the turf canopy.

Another key to maintaining a consistent green speed is controlling fertility levels in the grass plant. To avoid spikes of flush growth, we apply very small amounts of nutrients every 7 to 10 days throughout the growing season. Some golf courses will 'starve' their greens by applying very little fertilizer. This makes the green speed quicker but can result in poor turf conditions in the long term.

The last factor in determining green speed is the weather. High humidity and wet conditions result in a slower green speed because the grass blades hold more water and are thicker and wider than when the air is dry. We have experienced over 18" of rain during June and July. The excess rain has slowed the green speed down to 9.5' but fall is just around the corner and things should dry out and return to normal in a couple of weeks. Until then, we will do everything we can to keep the greens rolling smooth so you can enjoy your game.

And by the way, just because the Grass is Always Greener C.C. says their greens are running 12' on the Stimpmeter, doesn't make it a reality. It is very easy to manipulate the Stimpmeter to get any results your golfers want.

For more information on green speed:
http://en.wikipedia.org/wiki/Stimpmeter