Ever since the day the first
mechanized reel mower came along in 1830, there has been a steady improvement
in the conditioning and playability of putting greens. Today, mowing and
lightweight rolling are the primary practices used by superintendents to
achieve smooth, fast greens.
In the early days of golf, the
height of the grass on putting greens was controlled naturally by the intense
grazing of rabbits or sheep. This changed with the invention of mechanized
mowers and the ability to mow the turf lower and more consistently. Rolling was
also an important practice in the early days of golf, and it gained popularity
in the early 1900s. The equipment used at that time was what many today would
consider a heavy-weight roller, and frequent use resulted in soil compaction
and a decline in turf health. The goal
of rolling is to smooth the surface and minor imperfections, not compress the
soil, which puts stress on the turf’s root system. This is widely misunderstood by the golfing
public.
Over time, advances in equipment
technology resulted in mowers that can cut grass to less than 0.125” and a
variety of lightweight rollers to provide fast, true putting surfaces on a
consistent basis. In the quest for faster and faster green speeds many
superintendents have experimented with different mowing and rolling programs to
see what combinations are best for creating smooth, fast greens while
preserving the health of the turf.
As I said above, rolling is
widely misunderstood by golfers. When
the greens are fast, I often hear, “you must have rolled them this morning!” If only it were that easy! Greens rolling is done with lightweight
rollers shown in these photos. These
rollers help smooth out footprints, ball mark imperfections and generally smooth
the overall surface. They are not designed to compress the ground and the soil
to a point where undulations are removed or flattened. Heavy rollers used to compact gravel before
paving, for example, are doing the opposite of what is intended with the
lightweight rolling of putting greens.
So, what is the actual benefit of
rolling and how often is it done at Highlands CC? First, we roll 4 days/week. Specifically on Tuesday, Thursday, Saturday
and Sunday. After rolling a green one
direction, we pick up, on average, 6” on the stimpmeter. Research has shown that golfers cannot determine
a change in 6” of green speed. Simply
put, 11’0” feels the same to golfers as 11’6”.
What you may notice is smoothness in the greens following rolling. How long does rolling even last? It’s been shown that the benefits of rolling in the morning hardly last through the entire day.
Don’t get me wrong, rolling is a
critical part in what we do to keep the greens rolling fast, true and
firm. However, it is just one piece of
the puzzle. If fast greens were requested,
there are other practices that are more effective at producing faster
greens. Remember, green speed is not a
true speed. Speed is a relative number over
a period of time. For example, miles per
hour or feet per second. Green speed is
just a number that tells how many feet the golf ball rolled off the end of a
stimpmeter. Now that you understand
this, hopefully you see green speed as a function of friction that works
against a golf ball. If we can reduce
friction on the golf ball, we can get the golf ball to roll farther. So rather than the ball only rolling 10 feet
off the stimpmeter, it rolls 12 feet from it.
Thus, the greens are “faster.”
What can we do to reduce
friction on the golf ball?
Light Vertical mowing, or
grooming is an example of a
process to increase green speed because it slightly thins the turf, reducing
friction. Light topdressing
with dry sand is my personal favorite to increase green speed. The sand not only smooths imperfections,
but it lowers the height of cut of the
grass, from the ground up. Once again,
friction is reduced. Controlling moisture on the greens is a
great way to achieve less friction. Dry
turf is not as succulent as wet turf after a rainstorm. This is difficult to do in Highlands given
our extreme rainfall totals. Finally,
the height of cut of the grass itself is the most obvious way to
reduce friction that works on a golf ball as it rolls across a putting green. Speaking
of mowing, afternoon mowing, while the turf is dry, is a great
way to achieve faster putting greens. Reel
mowers always cut better when the grass is dew-free, and the turf is standing
upright.
As a superintendent, we use a
combination of the above practices to get the putting greens to their desired range
of speed. Again, while rolling is an
important element to faster putting greens, I think you’ll see that there is a
lot more to it than just rolling.
