Putting Greens and Maintenance

“Wow!” you think to yourself as you size up a putt, “this putting green is the nicest I’ve ever seen. It’s like a smooth carpet in the lobby of a luxury hotel!” It’s a pleasure to putt on an immaculate green, but how do they get it so short and smooth without it becoming a spotty, balding mess of dirt and grass patches?

History of Putting Greens

Up until the middle 1800s, putting greens were simply grass that was shorter due to sheep grazing there longer. Lawnmowers had not been invented yet. Greens were not specially built nor were they planted with specific grasses. They were selected because the spot was the right distance from the tee box, and the ground offered a natural shape that provided a reasonable surface for putting.
That all changed with the invention of the lawnmower. Then greenskeepers began to shape the putting green distinct from the surrounding area. They were contoured and graded in order to provide different challenges depending on where the hole was. Specific grasses were tested and used on putting greens due to their characteristics and suitability for growing at shorter heights.
Moving forward there are many factors that contribute to putting greens maintenance.

Many Grass Varieties

At that time, golf courses began to use three or four various types of grass seeds on greens.
Grass dealers developed specific mixtures which they protected like they were nuclear secrets.
But there were good reasons to use several different grass varieties.
The soil of each of the 18 different greens on a course varied widely in their quality.
Some could hold water well, and others had much more soil than others.
Some drained well while others did not.
A variety of grass families ensured that no matter what type of soil was on a green, there would be a reasonable consistency of coverage.
Also, grasses tend to grow at different speeds and at different times of the year.
Different grasses also provide tremendous variance in resistance to a golf ball.
This was especially acute if grass is a little longer, as the variances become more pronounced.
This was a challenge because golfers desired to have a putting surface that provided a consistent roll of the ball.
That’s when greens keepers began to employ shorter grass lengths.
However, shorter grass presented a number of new challenges.
Shorter grass was severely affected by heat and humidity.
This required more frequent sowing of fresh seeds, more maintenance of soil conditions and considerably more watering.

Large Hydroponic Systems

Today, science has advanced considerably in the construction of greens.
A modern green is really a large hydroponic system.
Construction starts with digging a hole the size of the green between 12 and 16 inches deep.
This hole is lined with a layer of plastic and then covered with gravel.
Drainage channels and sand are added.
Specialists then contour the surface to ensure rainwater runs off quickly and evenly, leaving no puddles behind.
All of this must be built in an area with lots of sunlight and free flow of air.
Once in the right grass seed is selected, the green needs lots of water and nutrients.
These days, greens keepers also use:
-Fungicides that keep diseases from overtaking the grass.
-Pesticides to prevent damage from invading insects.
-A number of different herbicides to kill weeds.
After the green has flourished, maintenance is key.
The green must be mowed every day with a special mower.
Workers must water and fertilize it constantly, adding the right mix of the above chemicals and aerating it on a regular basis.

Demand For Faster Golf Greens

Over the years, there has been an increasingly louder demand for lightning fast greens.
Unfortunately, this puts a lot of pressure on greenskeepers and golf architects.
The easiest way to increase speed on a green is to make the individual blades of grass shorter, but not all grasses can handle being cut so close to the earth.
For many years, the mowing height for an average golf green was about 0.125 inches, with a Stimpmeter rating around 8 feet.
For a variety of reasons, many golfers have asked for fast greens, and club superintendents are stretching the boundaries of good putting greens maintenance and construction in order to meet the demand.
Grass heights have lowered to around 0.100 inches which provides a Stimpmeter rating of around 10 feet.
Another challenge in maintaining grass growth is that fertility formulas have changed over time.
Several superintendents have reduced nitrogen levels to slow the growth rate of the grass.

Types of Grass

Today’s courses use Bermuda grass or bentgrass. Bentgrass is especially suited for courses in colder climates in the North.
Bermuda grass is often seen in warmer, southern regions.
Both varieties can be cut very short without difficulty, and provide a superior rolling surface.
Bentgrass has become more popular than Bermuda grass overall, and you’ll see it occasionally on courses in southern states.
For example, Augusta National features bentgrass greens.
The problem is that bentgrass is difficult to grow in the summer, so Bermuda grass will always be a staple in hot climates.
You may still see some courses using ryegrass or a bluegrass called poa annua, although these varieties are going out of style.
They are strong, reliable varieties, but the surface tends to be more uneven than that provided by bentgrass and Bermuda grass.
Historically, there was not much golf in the southern part of the country in the early 1900s.
It wasn’t until the 1950s when the first high-quality Bermuda grasses were developed that could be used on greens in hot climates.

Why use real grass at all?

All of this effort put into golf green turf maintenance and care brings up an interesting question: why use real grass at all?
With today’s modern artificial surfaces, wouldn’t it be easier to install artificial turf on golf greens and avoid all of the problems surrounding grass varieties, fungicides, insecticides and other aspects of putting greens maintenance.
It’s an interesting proposition, but artificial surfaces are still fairly expensive.
They also can have several problems with algae, which means workers still need to spray them.
They also heat up rapidly, so a cooling system of some kind would need to be installed to keep the green at reasonable temperatures.

Special Mowers

To keep the grass so short on greens, special mowers are used. Golf course mowers are reel mowers, not rotary like most lawn mowers used at home.
The reel spins and cuts the grass like a tight scissor cut.
The cut height is set by adjusting the difference between the front and rear rollers.
The blades must be sharpened on a regular basis, and require careful, consistent maintenance.
Superintendents use “feeler tape” of varying widths to gauge the clearance between the reel and the bed knife.
It can be adjusted down to thousands of an inch.
The tape is run between the reel and bed knife to make sure the clearance is perfect.
The blades wear down due to debris, sand, tiny stones, and general usage.
Special technicians grind the blades to razor sharpness several times a year.

Multiple Factors Affect Putting Greens Maintenance

Mowing height is only one consideration in golf course grass height maintenance.
The actual height of the mower depends on the:
-Type of grass.
-Number of golfers on the green every week.
-Changing environmental situations.
-Preferred speed of greens.
Most Bermuda grass and bentgrass varieties can be mowed as low as 1/8 of an inch, but it is preferable not to mow Bermuda grass lower than 5/32 of an inch.
These heights should be raised slightly in the summer due to the extreme heat.
Some courses will reduce mowing heights for short periods of time, for example for a golf tournament.
However, extremely short mowing heights can only be maintained for a limited amount of time.
Other techniques such as verticutting, rolling and brushing can be employed to help maintain the speed of the greens.

Leave it to Professionals

It is no wonder that given the precision heights involved, not every person is qualified to mow a green properly.
It takes training and experience to do it right.
Operators must be able to tell the subtle differences between an expertly mowed green and one that leaves almost indistinguishable errors that can prevent golfers from having a pleasant experience.
Every golfer has had a putt roll off-line for seemingly unknown reasons.
It could be the subtle changes in an improperly mowed green.

It Starts With The Right Type of Grass

As we have learned, there are a wide variety of factors impacting how golf course superintendents are able to keep golf greens grass so short.
It starts with the construction of the green itself, the selection of the proper grass variety for the climate, appropriate maintenance and watering techniques, and hiring qualified mowers who can operate precision machinery for the right outcome.
The result is a smooth surface every golfer can love.
Perhaps you are interested in a job as a greenskeeper.
With a golf management degree from the College of Golf you can get started on a path to career you’ll love. Contact us today.