The Need for Speed

A challenge that Golf Course Superintendents face is to achieve and maintain acceptable green speed while also maintaining healthy turf. Balancing the needs of the golfer with the needs of the turfgrass plant is an important aspect of any Superintendent’s job.

Golfers expect firm, fast greens. But what does it take to achieve this standard? How do we prepare the turf? How do we measure green speed? And, what might happen to a green if pushed too hard?

To measure green speed, Superintendents use a device called a Stimpmeter. It’s an inclined plane designed to release a golf ball at a consistent angle. In short, the distance a ball rolls is measured and averaged to get a number, or “Stimp”.

The Stimpmeter was invented years ago by a man named Edward Stimpson. The original purpose of the Stimpmeter was to ensure that all the greens on a course were of relatively equal speed.  The idea was to give superintendents a way to compare the speed of the 4^th green with, say, the 13^th and take steps to equalize them.  This was a good idea.

But sometimes bad things happen to good ideas.

 

Today, his simple tool, the Stimpmeter, is often misused to compare the speed of greens from course to course and unfortunately, to establish a benchmark of putting difficulty.

  

A Stimpmeter in action

From a competitive standpoint, that’s OK.  However, the quest for faster greens has consequences in terms of cost, environmental quality and the health of greens.  In short, speed can kill.  Here’s why:

Measuring to determine green speed

 

A healthy, vigorous green can be maintained at a very short cutting height for short periods of time without serious consequences if it’s been prepared properly and weather condition are acceptable.  Courses hosting tournaments often take months (and spend significant extra money) to bring greens up to an ultrafast speed for PGA Tour players.  For example, the greens at Augusta National or Oakmont may “stimp” up to 14 feet when properly prepared and dry.

However, fast greens are extremely fragile.

 If you compared them with human beings, it would be fair to say that their immune systems are weakened.  They become more susceptible to diseases and pests, and may require more chemical treatments.  Weather can also quickly destroy the health of an ultrafast green.  High temperatures and lack of moisture (or too much moisture) in the air or in the soil can be deadly to greens that are maintained at very short cutting heights.

Turfgrass root systems play an important role in the turf’s ability to withstand stress. Healthier, deeper roots translate into better stress tolerance.  So, as it turns out, the quality of a putting green at the surface is really dependant upon what is going on below the surface. In order for grass to grow at 1/10-inch height of cut or less, it needs deep, healthy roots. Good roots demand oxygen. In good soil, they get oxygen from the tiny pockets of air trapped between soil and sand particles.

Over time, the traffic from mowing equipment and golfer’s feet tend to compact the soil. When the soil becomes compacted, the air pockets on which the roots depend are crushed and the roots are, essentially, left gasping for air. Without oxygen, the grass will become weaker and eventually die.

Aerification is a mechanical process that creates more air space in the soil and promotes deeper rooting. In most cases it’s done by removing ½-inch cores from compacted soil, allowing for an infusion of air, water and nutrients. The spaces are then filled with sand “topdressing” that helps the soil retain air space. This is the typical, twice-a-year aerification that golfers have come to know and dislike since it is so disruptive.

 

 

 

a coring tine, a needle tine and a deep needle tine
 

 

 

But other aerifications take place throughout the year that don’t impact play but do play a critical role in growing and maintaining deep, healthy roots. In early winter and again in early spring, for example, a solid, deep-tine aerification is ideal for opening a channel down to the deepest level of the green. This process allows the plant to grow the longest possible roots at a time of the year when it is able and wanting to gain root mass. And since no cores are removed and the holes are so small in diameter, most golfers aren’t even aware that a cultural practice occurred. Later in the heat of late spring or summer, small needle tines are used to ventilate the green and allow for a gas exchange between the rootzone and the atmosphere. This is a critical cultural practice because as the soil temperature increases, the micro-organisms present in the soil become more active and consume more oxygen as a part of their life cycle; and just like animals breathing in and out, micro-organisms also release carbon dioxide as they consume oxygen. It is this gas, the carbon dioxide, that needs to be vented to the atmosphere or root mass will decline. Even worse for fine turf, if there isn’t enough oxygen present in the soil for micro-organisms to use, they’ll use sulfur instead to complete their life cycle and release hydrogen sulfide gas in the process, which is deadly to turf grass roots.

So, a lot of cultural work, below the surface, goes into maintaining firm, fast greens. Your Maintenance Team is constantly evolving techniques and procedures that maximize playability while minimizing surface disruption.  Our approach for the future must always be to improve the underground environment in which the root systems exist so that we can then provide the best possible above ground playing conditions. If we continue to care for the rootzone--the part of the green we DON’T see—it will in turn take care of that part of the green that we DO see, and continue to allow us the opportunity to provide firm, fast greens.

When it comes to putting greens… Out of sight should never be out of mind.