How high is too high? How low is too low?
As we all know, cutting heights – especially on putting greens – don’t stay at one set of height throughout the year. They’re raised and lowered accordingly. We may raise them because of stress, disease, aerification or because we’re heading into winter, to name a few considerations. We may lower them for an upcoming special tournament because we’ve come out of a stressful period, or are past aerification, or when we’re about to head into summer, among others reasons.
Geographic location plays a huge factor in some of these decisions as well, especially the one regarding winter mowing height. If you’re closed completely for the winter, your off-season height is likely to be much higher than a course that stays open all winter.
Course location also plays a factor in summer and in-season heights. Temperatures that routinely exceed 90 and even 100 degrees Fahrenheit no doubt require heights a little higher than courses located where the temperatures are moderate during the summer.
And, of course, slope of greens determines heights as well. For instance, .100 inch on one course may be an impossible height to get down to on another course that has severe slopes on the greens’ surfaces.
Height of cut must also be considered in conjunction with many of our other cultural practices. If you roll – and how often you roll – determines height; timing and frequency of verticutting determines height; irrigation and wetting agent use determine height; topdressing applications determine height; fertility applications determine height. This list could go on, so let’s just say a lot of our cultural practices determine the heights we end up setting, as well as manipulating, throughout any one year.
What we’re after, ultimately, is consistent ball roll. If you can manage a true roll at a higher height, and there’s no pressure to increase that roll (speed), then by all means manage at that height. But in the real world, we all know that that pressure will indeed show up from time to time. We aren’t always going to be able to manage the greens at the height we know they would be happiest.
Back in the day, .100 inch was considered the low mark that anyone dare go. But, of course, like the four-minute mile, that mark was shattered long ago. Many now routinely manage their greens at .100 inch or lower.
One of my neighbors here in western Washington, Craig Benson, the superintendent at Meridian Valley Country Club in the shadow of Mt. Rainier outside of Seattle, says his in-season height is .090, although he specifies a difference between walk mowers and triplexes.
“[The height is] .090 with the walkers and .110 with the triplex [in the summer],” Benson said. “We go to .125 for the winter.”
At my course, we drop to .100 (walk mowers) for special occasions in season, although our average summer height is .110. I usually raise them anywhere from .125 to .135 through the winter, although I do remember raising as high as .165 during a stressful winter several years ago.
Again, these numbers are all subjective. One thing to keep in mind is to keep a good range for your course. If you drop to .090 (or lower) in the summer, your highest winter height – assuming you are open in the winter – should be limited accordingly. I don’t think anyone dropping to .085 would want to raise to .175, as that range is too large.
But for the course that does keep a .115 or .120 in-season height, there’s no reason it can’t get up into that .165 or even .180 range in the off-season. In fact, Vance Much, another neighbor of mine and superintentent at the wonderful resort course Semihoo Country Club on the Canada-Washington border, has gone has high as .200 in the past.
“This dates back to our moss fighting days,” Much said, but adds his normal off-season height is in the .140 to .150 range.
“If a cold snap is predicted during the winter,” Much said, “I will grow them longer by just de-dewing with the triplex in the morning.”
So, how high is too high? How low is too low? There is no set answer. Find a range that fits your golf course, and don’t be afraid to move about that range as the conditions and practices dictate.