The long and short of it

Maintaining healthy turf requires a balance between plant health, meeting budget and addressing members’ sometimes-lofty expectations.

The right mowing practices minimize those risks to the turf posed by weather and disease while still providing golfers with the conditions they crave.

Traditionally superintendents have raised their mowing heights during the peak of the season to minimize the risk of heat stress and allow the root of the plan to flourish.

The key to having a thriving root system in the spring and summer is proper fall preparation, says Mark Kuhns, director of grounds at Baltusrol Golf Club and a past president of the Golf Course Superintendents Association of America.

“It’s important that you’ve all the proper aeration in the fall and early spring, and that you’re doing your dressing and sand topping on a 10- to 14-day basis,” Kuhns says. “You have to take care of the things that are going to affect you.

“If you have a history of disease on your greens you’d better be treating about this time of year,” he adds. “Getting that early makes a difference between a strong plant and a weak plant.”

Kuhns appreciates fast greens as much as anyone; he worked at Oakmont before coming to Baltusrol, but says it’s important to resist the temptation to cut too low, too early.

“A lot of young superintendents don’t understand the correlation between root growth and top-growth of the plant,” he says. “A lot of guys start mowing it down because their members want the fast greens right out of the gate. So they begin to mow them down too soon and the root systems don’t have a chance to grow, to go deeper into the soil. We try to maintain a higher height of cut even if it’s above an 1⁄8th inch.”

Today’s modern grass strains have proven more amenable to heat and humidity, even at lower mowing heights.

“We’ve seen the development of grasses that seems to perform better at lower mowing heights,” says Dr. Jack Fry, professor of turfgrass science, director of Rocky Ford Turfgrass Research Center. “That all occurred with the release if the A-series grasses, like A4. Not that they don’t benefit when they’re mowed a little bit higher, but they tolerate heat and they look good when they’re mowed low. They perform well at those lower mowing heights, which we didn’t use to see.”

Even grasses that perform well or better at lower mowing heights still benefit from being mowed a little bit higher, Fry says.

“We’re just talking millimeters here but slightly increased mowing heights will result in improved root development,” he says. “That’s really a key on the putting green. If we can maintain root health, we maintain the health of the plant. If we ever see decline in a putting green, it’s usually roots that go first and we don’t see that happen. Then chutes starts to decline and then the quality goes down.”

There is no one-size-fits-all approach when it comes to mowing. Each superintendent must deal unique circumstances. Huntingdon Valley Country Club outside Philadelphia is known for its challenging putting surfaces. Superintendent Scott Anderson watches over turf that is comprised primarily of old-style Penncross and other classic laterally growing bentgrasses.

“We embrace those,” Anderson says. “We do it from a playability standpoint. It adds interest to the grain when you read a putt as opposed to the upright bentgrass where you just read the contours and putt. Here, you have to look at the contours as well as what the grass is doing. Am I putting into the grain or am I putting cross- grain?

“What that adds from a health standpoint is, we’ll have blades that are laying over and longer than the mowing height. Even if we’re in essence cutting short, the blades are allowed to run out so we get more leaf surface and less plants per square inch.

“You get great rooting that way in the spring,” he adds. “Then we’ll remove more of the grain in the summertime to have less leaf surface for the plant to support. We do everything we can to push roots. Having more leaf surface in the spring correlates to deeper rooting.”

“Cutting short” can increase the risk of turf damage during mowing. But Anderson points out that today’s state-of-the-art mowers minimize the risk.

“The new advances in floating head technologies have allowed us to mow shorter with less issues with gauging or scalping,” he says. “We just got a new batch of John Deere greens mowers and they are absolutely phenomenal.”

Mike Bair is the director of agronomy at the Stockton Seaview Resort and Golf Club just outside Atlantic City, N.J. At deadline, Bair was preparing the resort’s Bay Course for the ShopRite LPGA Classic. The course features undulating greens and Bair has found a mower that will give him the condition he ranks without undue risk to the turf.

“We’ve been using Toro equipment on our greens,” he says. “Because of the undulations that we have we do get better cuts with those mowers.”

Rolling can often provide an effective alternative to mowing, allowing the superintendent to create the types of green speeds his members crave without the risk of cutting so low that the health of the plant is endangered.

“We try to alternate with mowing and rolling,” Bair says. “Technology has changed. We don’t have to go as low.”

Advances in turfgrass science have influenced mowing habits. Anderson is utilizing a new strain of Bermuda grass, Latitude 36, on his practice tees and is now incorporating it on the golf course itself. In addition to being more cold tolerant than some other grasses, Latitude 36 thrives during the spring and summer months. Consequently, divots heal very quickly, in seven to 10 days or so, compared to the 21 to 28 days typically required with bentgrass.

“We’ve installed two new tees on par threes,” Anderson says, “and we’re sodding those with Latitude 36. They’ll be so aggressive they may have to be mowed more often than bentgrass tees during the summer months. They thatch up a lot and probably will have to be aerated more.”

Fred Biggers is the head superintendent at the Wintergreen Resort in Roseland, Va. A veteran of 30 years in the industry, Biggers has been at Wintergreen since 1999. He is responsible for two golf courses: Devil’s Knob, located on a mountain, and Stoney Creek, a 27-hole layout situated in the valley below.

In 2007, Biggers installed Cavalier zoysia grass on nine fairways at Stoney Creek. Zoysia is native to eastern Asia, notably Japan. It was first utilized in the U.S. in Texas. It provides a consistent playing surface; hitting off of a zoysia fairway feels like hitting off a plush carpet.

More importantly, from Biggers’ point of view, zoysia can be cut lower than other grasses with no ill effects. And it costs significantly less to maintain, which frees up dollars for other projects.

“It doesn’t grow fast,” Biggers says. “You might have to mow only 40 times a year compared to maybe 150 with bentgrass. And it takes a pound or less of fertilizer per year.”

In today’s world, any development that will allow a superintendent to reduce costs will attract his interest. But maintaining quality playing conditions is no less important. And the quest to create and maintain those conditions goes on.

Rick Woelfel is a Philadelphia-based writer and frequent GCI contributor.

For more information...

Looking for more data and opinions about mowing heights? Check out these online resources.

• “Turfgrass Maintenance Mowing,” by Tom Samples and John Sorochan, University of Tennessee Extension. Enter bit.ly/1p753Km into your browser.
• “Turfgrass Mowing,” by Tom Voight, University of Illinois Turfgrass Program. Enter bit.ly/1vulUeB into your browser.
• “Mowing Height, Mowing Frequency, and Rolling Frequency Affect Putting Green Speed,” by Jay Richards, Doug Karcher, Mike Richardson and Josh Landreth, University of Arkansas, Department of Horticulture; Thom Nikolai, Michigan State University, Department of Crop and Soil Sciences; Aaron Patton, University of Arkansas, Cooperative Extension Service, Arkansas Turfgrass Report 2007. Enter bit.ly/Tn3u0N into your browser.