Taking a Firm Approach

While different varieties of grasses require different mowing strategies, keeping the greens in top condition is still the number-one priority for course maintenance crews.

A flurry of golf course renovations has seen many properties, particularly those in warm-weather climates, convert the grasses on their greens to hardier varieties that provide a better putting surface for their golfers. With a change in grasses, however, grounds crews often have to make adjustments to their maintenance practices as well, while still striving to provide the top-notch greens that are the key to happy golf course consumers.

“If the rest of your course is perfect but the greens are terrible, people are not going to play your golf course,” says Dan Johnson, Golf Course Superintendent at Old Hickory (Tenn.) Country Club.

Old Hickory converted its greens from bentgrass to MiniVerde UltraDwarf Bermuda in July 2013. “We thought we could get a higher-quality putting surface for a longer period throughout the year,” notes Johnson.

SUMMING IT UP New varieties of grasses, along with the conversion of putting surfaces from one type of grass to another, have altered mowing strategies and other maintenance inputs on golf course greens. Keys to maintaining healthy greens include daily monitoring, communication among staff members, and promptly addressing any issues such as improper cutting by the mowers, disease, and color variations. Regular back-lapping, grinding and sharpening of reels are keys to consistent mower performance.

The Bermuda greens offer premium conditions for 10 to 11 months, Johnson explains, while the bentgrass greens provided a good putting surface from September to mid-June, then struggled to get through the summer. “The Bermuda is dormant in the wintertime, and it putts really, really well,” he adds.

The Country Club of Jackson (Miss.) also switched from bentgrass to Champion Bermuda greens on its 27-hole course six years ago. Certified Golf Course Superintendent Stanley Reedy says the property made the change to provide golfers with a better playing surface.

Colbert Hills Golf Course, a 27-hole property that serves as a research facility for Kansas State University in Manhattan, Kan., features different varieties of bentgrass on its 18-hole championship course and its nine-hole par 3 course.

In the past year, Kansas State has performed four research trials at Colbert Hills, including two on the greens for wetting agents and fertilization, to learn how the turf reacts to different scenarios and products, reports Matthew Gourlay, CGCS, Director of Golf Course Operations.

A Cut Above
No matter what the character of the turf involved, mowing practices play an integral role in greens maintenance.

The Old Hickory grounds crew mows the greens every day from the beginning of April through the end of October. “After that, we mow as needed,” adds Johnson. “We hardly ever mow them in the winter unless we’re cleaning up debris. We’ll roll the greens in the winter to smooth the surface.”

The height of cut varies from .165 inches in the fall to .100 or .110 inches in the summer. Johnson says the crew uses ride-on triplex greens mowers about 90 percent of the time. “We walk-mow if it’s real wet and we don’t want to track up the surrounds,” he explains.

Johnson typically sends out two mowers onto the 18-hole course when the staff ride-mows the greens, but he will use five mowers to walk-mow. In addition, he generally keeps the same four or five crew members in the mowing rotation.

“They know the equipment, and I trust them to do a quality job,” he reports. However, he adds, “I try to have everybody cross-trained so they can do every job.”

The Old Hickory staff verticuts the Bermuda greens every week to remove organic matter from the putting surfaces and prevent thatch buildup. In addition, the crew grooms and brushes the greens four or five days a week during the heat of the summer. “The mower attachments help stand up the grass in front of the blade, so you can get a cleaner quality of cut,” Johnson explains.

Weather dictates mowing strategies as well. “My program will change on the fly every single day. You’re always tweaking it somehow based on weather conditions,” Johnson notes.

Heated Action
At the CC of Jackson, “The cooler the temperatures, the less we mow,” notes Reedy.

The CC of Jackson staff also increases the height of the grass in the winter and lowers it in the summer. Typically, however, the grounds crew mows the greens six days a week. Normally, the crew cuts the greens at a height of .125 inches, but depending on circumstances, the height of cut can range from .115 inches to .145 inches.

“We send out seven mowers to walk-mow all 27 holes,” says Reedy. He varies the number of grounds crew members who mow the greens “depending on what’s going on that day.”

Despite the change from one variety of grass to another, however, Reedy says the time his crew spends mowing the greens has remained about the same. “We mow the Bermuda more in the summer, but we mowed the bentgrass more in the winter,” he explains.

Cut and Roll
While the Colbert Hills grounds crew mowed the greens daily last year, this season the staff has mowed them four to seven times a week, alternating between mowing and rolling the greens each day. “We saw in our research that we got more consistent green speeds by alternating between mowing and rolling. We have faster greens, and we can increase the height of cut,” explains Gourlay.

The staff mows the greens at .125 inches. Gourlay rotates mowing duties among the 13 crew members. This practice allows him to cross-train the staff that, in addition to full-time assistant superintendent Shane Rengstorf, is made up of KSU students who work part-time. With five acres of greens to maintain, the staff ride-mows the putting surfaces, which average 7,200 to 8,000 sq. ft. in size, with triplex mowers.

“Everyone loves to mow greens and everyone hates to rake bunkers, so we try to keep everyone happy,” says Gourlay.

The size of the USGA greens at Colbert Hills helps keep them in prime condition as well. “We have big greens, so we can put pins all over the place and golfers won’t compact them,” reveals Gourlay. The Colbert Hills staff also verticuts the greens twice a year to clip any grass blades that have folded over onto their sides, which affects greens speed.

The quality of cut is only as good as the equipment making it, however, and regular mower maintenance is also critical to good greens mowing practices. The Old Hickory CC staff keeps mowers in top condition by back-lapping the reels every day and grinding them once a month. Frequent top dressings also put wear and tear on the equipment, notes Johnson. “Having sharp mowers is the key to success,” he says.

The CC of Jackson has two mechanics on staff to keep mowers running in top form. “They have a big responsibility,” states Reedy. “If they fail at their job, there’s no way we can do ours. But these guys are really talented.”

With one part-time mechanic on staff, Colbert Hills grinds its mower reels as needed. “It’s a visual aspect. If the cut doesn’t look good, we’ll pull them off and sharpen them that day,” Gourlay explains.

More Than Mowing
Johnson has changed some maintenance practices since Old Hickory made the switch to Bermuda greens. “Our mechanical inputs have increased, but our watering inputs have decreased,” he says. “We top-dress a lot more than we ever did with bentgrass.”

With the heat-tolerant, warm-season Bermuda grass, the crew spends less time hand-watering and monitoring the moisture in the greens in the afternoons.

During the Tennessee winters, however, the Bermuda requires some labor when the maintenance staff has to cover and uncover the greens when the temperature drops below 26 degrees.

The Old Hickory crew rakes the greens three days a week year-round. In addition, the staff aerifies the greens every year in the middle of the summer when the grass grows most aggressively. Aerification gets more oxygen into the root zones and improves drainage, reveals Johnson.

“With Bermuda you can be more aggressive and defensive,” he says. “With bentgrass you’re just trying to get through the summer. You’re not just trying to keep the Bermuda alive. You try to keep it as perfect as you can.”

Of course, the weather affects other inputs besides mowing as well. “Whether it’s Mother Nature or irrigation, we water every single day,” notes Johnson. “The amount of water I put on the greens is based on weather conditions. If it’s windy and dry, we use more water. If it’s cloudy and humid, we use less.”

To keep the greens at their best, Johnson believes proper fertility, proper use of fungicides when disease pressure is high, and proper management of organic layers are vital as well.
At the CC of Jackson, Reedy says, some maintenance practices changed as well when the property switched from bentgrass to Bermuda greens.

“We didn’t top-dress the bent every week, and we didn’t groom and vertical-mow the bent as much,” he reveals. “We don’t have to have a lot of guys out syringing now, and we don’t need fans now. We used to have them on every hole.”

Fertility and disease-control requirements for the two grasses have been about the same, Reedy notes. The CC of Jackson staff aerifies its greens twice annually, and this year the crew will aerify them back-to-back in July and August.

“We have to do it in the heat of the summer when the grass can recuperate, and the membership liked it better this way,” Reedy explains.

On Mondays, the CC of Jackson grounds crew top-dresses the greens to smooth the surface and to reduce organic matter buildup, and then verticuts and grooms the greens.

Colbert Hills can go one to two weeks without watering after a deep rain, depending on the subsequent weather. The Colbert Hills staff does not aerate its greens in the spring and the fall, but it heavily top-dresses its greens every three weeks during the golf season, to maintain proper fertility.

“Our variety of bentgrass is more resistant to dollar spot, so we don’t have to spray as many chemicals,” notes Gourlay. “As long as we monitor our thatch layer, we’ve noticed that we haven’t had the need to aerify the greens.”

This practice gives Colbert Hills an advantage over other area golf courses that lose play when they aerify their greens. “It’s a huge opportunity in the spring and fall to get extra revenue,” Gourlay reports.

Change Reaction
Old Hickory’s Bermuda grass is firmer than the bentgrass in the summer, and Johnson says any change requires an adjustment period. However, he adds, golfers have had a positive response overall to the new putting surfaces.

“The members absolutely love them. The greens roll extremely well. The ball roll is faster, and that can be a negative to people until they adjust, ” reports Johnson. “Some of our older members don’t hit the ball as high or with as much spin, so they have a harder time stopping the ball. But the Bermuda will soften up over time.”

Gourlay, a third-generation superintendent, has been at Colbert Hills since opening day in May of 2000, when he worked at the property as a cart boy. He has served as the course’s superintendent for eight years, but says greens maintenance has changed tremendously since the 1980s and 1990s when his grandfather and father last worked in the field, respectively.

Some of the changes include faster greens speeds, better mowers that provide a better quality of cut, the use of moisture meters to monitor moisture in the greens, different chemicals, and different varieties of grasses.

One aspect of greens maintenance has not changed, however. “Our ultimate goal is to provide the healthiest plant out there,” says Gourlay. “The most time golfers spend on the course is on the putting greens; it’s what they always talk about. Great greens can hide some other blemishes. If they like the greens, they can forget that their beer wasn’t cold enough or that the tire pressure in the golf cart wasn’t quite right.”

The keys to maintaining healthy greens, Gourlay believes, are daily monitoring, communication among staff members, and promptly addressing any issues such as improper cutting by the mowers, disease, and color variations.

Reedy identifies several essential components to maintaining top-notch greens, starting with the personnel and assistant superintendents. The Country Club of Jackson divides duties among four assistant superintendents. One assistant oversees the property grounds and common areas; one is in charge of in-house projects; the remaining two have leadership roles in maintaining the three golf courses.

In addition, Reedy believes that the greens must be built correctly, and maintenance staffs need the right tools—from equipment to irrigation systems to fertilizers—to do their jobs. “If you’ve got good greens, usually the members will be happy,” Reedy says.