If you are an avid golfer, or perhaps an arm-chair golfer watching the Masters or other important golf tournament, you might wonder how greenskeepers get the golf course so smooth.
Turfgrass takes up about 40 million acres in the United States. The recommended cutting height to maintain a healthy lawn with the least amount of inputs* is 3 inches. What if a homeowner impulsively wanted to develop their own putting green? Let’s assume they start by mowing a 4000 sq. ft. area down to a ½ inch height! This would stall their rotary mower and result in an area covered with excessive grass clippings. Even after raking away the clippings, a sparse bumpy landscape that would be just as much soil as vegetation would be the hard-earned result! It would be a very poor putting surface; in fact, it would not even be a good site to play croquet. Creating and maintaining a golf course – even just a putting area – is best left to the professionals!
So how do golf courses make the grass surface so smooth? Here’s what I believe are the five most important steps in the correct order of importance.
- Choose the best grass for the site. The average person does not think about grass very often, and most would struggle to name three different species. But, there are a variety of turfgrass species, each with their own attributes. And, just like roses and fruit trees thrive in various weather zones, the same is true for turfgrasses. It’s also necessary to choose a turfgrass species and variety that performs best at a low cutting height to make and maintain a smooth turfgrass surface.
- The cutting height and mowing frequency are the two most important maintenance practices in creating a smooth surface on a turfgrass stand. On a golf course putting green, the cutting height should be no greater than 0.189-inch! In all truth, that is rather tall to maintain a firm smooth surface. Additionally, on a golf course, grass is mowed almost every day and sometimes more than once a day with a reel mower. The original labor for mowing golf course greens actually came from sheep and rabbits feeding daily on the course. No kidding – before lawn mowers were invented, these animals were part of the original greenskeeping team! The truth is, those surfaces were probably not very smooth. But, low cropping/cutting at a daily frequency was paramount in creating the playing field and the game. Today, a low cutting height and high mowing frequency with a reel mower helps fill in voids by forcing the grass to grow somewhat laterally.
- Fertility, primarily with nitrogen, is important because it allows the grass to grow and fill in barren areas.
- Sand topdressing is important to keep a turfgrass surface smooth and firm. Sand topdressing was initiated by simply throwing shovels of sand on golf course putting greens. Then, a mat was used to drag the sand into the canopy. Today there is a lot precision equipment dedicated to topdressing putting greens, and even athletic fields. This step helps keep the surfaces firm and smooth even under high foot traffic.
- Rolling is an odd-looking mechanical practice for the non-turfgrass junkie to wrap their head around. Rolling results in many benefits, but none more practical than it creates a smooth surface that results in longer ball roll and increased customer satisfaction.
There are other practices that help create or maintain smooth turfgrass surfaces, but they are more related to turfgrass health, such as irrigation, or thatch reduction, such as cultivation. If a homeowner truly wants that putting green, a few years of mowing to a height of 0.189 inch – and daily – with a reel mower, feeding the plants nitrogen and occasionally topdressing with sand, the long term result would most likely be an adequate annual bluegrass putting surface. However, that’s another story.
By Thomas A. Nikolai, Michigan State University
*Inputs in agronomic terms means anything that goes into creating a crop. This counts items like seed, soil, fertilizer, pesticides, water, and labor.
About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.