Golfing
Dave Sartwell
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Building outstanding greens on a golf course requires a combination of both art and science. The art is in understanding what will be beautiful to the eye and the science is the understanding of both the agronomy and physics that will sustain that art over time.
The start of the building of the green begins with an understanding of what lies beneath the existing topsoil. A bulldozer removes all of the surface cover and the contractor sets his grade stakes. These stakes will be a rough outline of the green the architect has drawn and will show the elevation changes as well. The earthmovers then start the process of taking away or adding to the surface to establish the contours of the green.
These cuts and additions have to be done carefully for it is this subgrade that often determines the quality of the putting surface you will eventually enjoy. The contractor shapes the green contours exactly as the eventual green will be, compacting this level until there will be no movement once completed.
Of all of the steps in the process, this is one of the most important. The foundation upon which the rest of the green is to be built has to be as perfect as possible. I didn't understand this until Dr. Michael Hurdzan, the noted contractor that built Turner Hill, explained it to me.
"The amount of water retained by a soil profile against gravity is inversely proportional to the depth of that profile," he said. "What that means is the deeper a soil layer is, the more water will be removed from the top of that layer by gravitational forces, and the shallower the profile, the wetter the top surface will be."
So, if the amended soils that are put over the subgrade are not of the same depth all over the green, there will be spots where the water is drained away from the surface at different rates than other parts of the green. This means that you could have wet spots and dry spots on the same green. The golf course superintendent will then be confronted with the problem of how to water the green to get a consistent putting surface over the whole green.
This is complicated a little by the different undulations that are to be built into the green. As Bernard Darwin once wrote: "undulation is the soul of the golf course." Undulations on the green and the construction of the surrounding traps and approaches can make for spectacular artistic designs.
Once the subgrade is set, the drainage tiles are put in place. There is a whole science to this as well. The green subsurface is trenched and then small pea stone is dropped into the trenches. These trenches have to be carefully graded so there is a steady fall away from the green so there are no low spots. The tile is then laid in the trenches and covered.
This is followed by the installation of the sprinkler heads. Again, this may sound simple, but proper coverage and overlaps are critical to the eventual health of the green.
Now comes the actual building of the putting surface. There are two popular methods that are employed. One is called the USGA Method and the other the California Method. The USGA Method uses a base of small gravel and course sand covered with about 12 inches of special sand and a small amount of organic matter. The California Method is all sand with a topping of fertilizers and organic matter such as seaweed extract.
In either case the edges of the green are ringed with a liner that prevents the water from being pulled away from the green by the vegetation surrounding the green. This pie shell is then filled with the amended soil that is almost pure sand.
Here is where the art of contractor and architect meet. The edges of the green must blend into the fairway in such a way as to have a smooth and pleasing-to-the-eye contour.
"The ability to blend these surfaces together into one flowing contour is a skill that separates true construction artists from dirt movers," said Hurdzan. "The personal attention and pride of workmanship of the man applying the final grade establishes the character of each feature of a golf course."
To this amended soil is then applied the putting surface. Modern mowing equipment and grass types can allow the new surfaces to be mowed down to as little as one-tenth of an inch. Because of this, course architects have to be careful how much slope is put into a modern green. There is a whole science and art that is applied to these design concepts we may approach in another column.
So, the next time you walk up to a green, stop and appreciate the art and science that has gone into preparing the surface upon which you are playing. Keep your bag well away from the approaches. Walk softly on the green and repair your ball marks carefully.
There has been a lot of care in designing and constructing this surface. The greenskeeper and his crew have worked hard to make them smooth for you. Do your part by respecting the surface and leaving it as pristine as possible for the folks behind you.
Dave Sartwell is an outdoors columnist for the Times. Contact him at davidsartwell@comcast.net.
