Golf Course Readiness
The challenge of switching grasses at Pinehurst No. 2
Conversion to bermudagrass greens from bentgrass has paid off, superintendent says
February 3, 2022 By Mike Jiggens
Any golf course that plays host to a PGA Tour event can be considered high end. Conditioning is spot on, greens are apt to be firm and fast, bunkers are raked to perfection, precision shot-making is demanded, and distances usually exceed 7,000 yards.
And then there are golf courses that are beyond high end, and which a lucky few are privileged to play. Many of these serve as the venue for the Tour’s major tournaments.
One such course is simply referred to as Pinehurst No. 2. It’s the crown jewel of a collection of nine 18-hole courses and one nine-hole layout that help make up the renowned Pinehurst Resort in Pinehurst, N.C. It has been the site of three U.S. Open championships and will be the tournament venue again in 2024. In fact, an additional four U.S. Opens have been penciled in for Pinehurst No. 2 as far ahead as 2047.
Under the direction of architectural firm Coore & Crenshaw, the golf course underwent a significant renovation project in 2010-2011 that included a return to designer Donald Ross’ original vision and the resurfacing of its greens to ultradwarf bermudagrass from bentgrass.
Pinehurst No. 2 superintendent John Jeffreys shared the story of the restoration project and its challenges with University of Guelph turf management students in November during a virtual presentation.
He described the era from 1962 onward as a “dark period” in the course’s history, noting it had diverted from its intended rustic look to a more manicured appearance to take on more of an Augusta National look. It was decided at the time that adding more grass would make the property look better and not appear as “scruffy.” Both the 1999 and 2005 U.S. Open tournaments were played under such grassier conditions. But, after the 2008 U.S. Amateur at Pinehurst No. 2, it was determined the golf course no longer resembled the original Ross design and was ripe for a change. Old photographs from its early years convinced Bill Coore and Ben Crenshaw to remove 35 acres of turf and replace it with sandy wiregrass as well as areas covered in pine straw. The $2.5-million restoration project included reducing the number of irrigation sprinkler heads to 500 from 1,450.
“That way the edges could stay unkempt-looking or rough and more Pinehurst-like,” Jeffreys said.
The preference was to promote the golf course as firm and fast and not necessarily lush and green. Jeffreys, who has worked at Pinehurst the past 21 years, said it was challenging to keep the course’s bentgrass greens alive throughout the year. Since the putting surfaces were converted to ultradwarf bermudagrass, it’s been a lot less “mentally draining.”
From 1907 – when Pinehurst No. 2 was first constructed – until 1935, its “greens” were simply sand surfaces that were oiled in to allow for smooth putting.
“Donald Ross couldn’t find a grass suitable for our hot summers and cold winters,” Jeffreys explained.
It became necessary, however, to grass the greens so that Pinehurst could host the 1936 PGA Championship. Ross selected an older variety of bermudagrass and overseeded it with an Italian ryegrass to accommodate the tournament. The greens eventually gave way to bentgrass until they were resurfaced with ultradwarf bermudagrass during the Coore-Crenshaw renovation project.
Tarping greens is key
To better safeguard his new greens, Jeffreys covers them when forecasted winter temperatures dip below designated thresholds. The process is labour-intensive, he said, but not as much as having to hand-water the greens.
The greens were sodded to ultradwarf bermudagrass between U.S. Thanksgiving in 2010 and New Year’s Day of 2011. Evergreen turf covers were used atop the new greens for their desired greenhouse effect. Jeffreys said black tarps were chosen to more effectively draw sunlight and heat.
He said it takes his staff about two hours to cover the greens at the end of the winter season golf day. If overnight temperatures are expected to be 20 degrees Fahrenheit or below, the greens will be covered. If the next day’s high temperature isn’t expected to go above freezing, the greens will remain covered.
Greens were covered 25 nights during the 2014-2015 winter golf season when the temperature threshold was established at 25 degrees (it was adjusted to 20 degrees in 2018). In 2015-2016, greens were covered 12 nights. The following season, they were covered 13 nights and then 19 nights in 2017-2018. By the 2018-2019 season, the temperature threshold was adjusted to 20 degrees, and only six nights required covers. Greens haven’t needed to be covered at all the past two full seasons.
The drawback to covering greens, he said, is the safety risk it can present. He noted some of his staff have experienced back injuries when strong winds have worked against the individuals laying the covers down, and occasionally a stake will fly up from the ground and strike someone.
In spite of such minor injuries, the covers have been effective.
Jeffreys said while air temperatures might be about 25 degrees, the temperature beneath the tarp are often closer to 50 degrees, especially when pine straw is placed atop the cover on particularly cold nights.
“It was a significant warming, knowing that we weren’t going to have winter injury. It’s a great insurance policy and helps you sleep at night when it’s getting cold, and you know your greens are covered.”
The greens at Pinehurst No. 2 are between 5,800 and 7,000 square feet in size. Jeffreys said covering his practice putting green, however, presents a biggest challenge. At 75,000 square feet, it requires six covers fastened together by Velcro.
“Covering that is a nightmare.”
Pinehurst No. 2 does not permit twilight play, and the absolute last tee time allowed during the winter season is 1 p.m. This enables staff to cover the greens before dusk sets in. All rounds must be a full 18 holes, and no nine-hole nor partial rounds are permitted.
Jeffreys said one of the things he likes best about his ultradwarf bermudagrass greens is the amount of traffic they can withstand. They can be mowed and rolled more aggressively with little to no stress.
During the last U.S. Open played at Pinehurst No. 2, when the greens were still grown to A-1/A-4 bentgrass, they were mowed at .125 inches.
“It’s not a very low height of cut, but we set up our bedknives to make them more aggressive so that the effective height of cut was slightly below .100, and we had counter-rotating brushes out in the front of the mowing units, so it effectively raised the grass, cut it and set it back down.”
In the end, there wasn’t much grass above .0625 inches, he said.
Going into the current winter season, the ultradwarf bermudagrass greens are being mowed at .125 inches. The desired speed and texture of the greens is achieved through double mowing. Mowers aren’t set low, but they’re set more aggressively, Jeffreys said.
During the summer, greens are double mowed daily. The first significant event held at Pinehurst since the restoration of its greens was the 2019 U.S. Amateur, held during the month of August. Greens were mowed 84 times that month. Each morning they were cut down and back in the same pass, and the process was repeated on many afternoons. This allowed the greens to stimp at 15.
For the 2024 U.S. Open, Pinehurst’s greens will “just be waking up” before the June tournament, requiring an adjusted height of cut and different mowing practices. Desired green speed is typically achieved through frequency of mowing, vertical mowing and topdressing. The 13th green is stimped daily while various data is recorded, such as whether greens are both mowed and rolled, mowed only, topdressed and what fertility inputs were made.
“That way we can make more informed decisions and we’re not just guessing.”
Vertical mowing is a preferred practice at Pinehurst No. 2 to minimize the effect of grain on ball roll. Jeffreys said the ultradwarf bermudagrass greens tend to be in better shape following a USGA championship event. That wasn’t the case when the greens were grown to bentgrass.
“There was more traffic, more ball marks, more stress. I felt that with cool season greens that, after an event, the greens were worse. With the ultradwarfs, you have more people, more equipment, and more time to get things done in the lead-up advance weeks, so the greens are always better after a championship.”
The golf course’s fairways are also grown to bermudagrass. Jeffreys said it means having to work a little harder to get the fairways in the right tournament conditions by brushing, mowing side to side and using plant growth regulators. Fairways can be sprayed with Roundup in January while they are still dormant to kill any winter annual weeds that may have popped up.
He said the dollar-to-dollar expense in fungicide costs is about the same between bentgrass and bermudagrass.
“The difference with bentgrass is, if we saw a disease, we could spray it and it could recover quickly. With bermudagrass, there seems to be a two-month delay. The disease is active when the soil temperature is 85 degrees in June or July, but the symptoms of that disease don’t show up until August. So, you missed your window to apply fungicide and you don’t see the effects until later.”
Moisture management also varied between bentgrass and bermudagrass. The former bentgrass putting surfaces would turn purple and footprints were often visible during periods of drought. Once hand-watered, it popped back up within an hour. Bermudagrass turns a khaki-brown colour when it wilts and may take up to seven days to recuperate.
“It almost goes into a protection mode where it’s going dormant, and it takes a while to wake back up.”
The greens had been rebuilt in 1996 to USGA specifications – in a project overseen by Rees Jones – and based on drawings from the 1962 U.S. Amateur. Aerial photographs taken in 1943 were used during the Coore-Crenshaw project. Considered high in resolution for the time, the photographs offered precise details that enhanced the project.
Pinehurst No. 2 has significantly expanded its length over the years. When it first opened, it was slightly longer than 6,000 yards, but currently stretches beyond 7,600 yards, but usually plays to about 7,300 yards.
More than 300,000 rounds of golf were played in 2021 at Pinehurst Resort’s 10 courses, including more than 40,000 alone at Pinehurst No. 2. The COVID-19 pandemic forced a six-week closure of the resort’s hotels in March 2020, but golf continued to be played. The pandemic reduced the resort’s employee complement to about 90 from about 1,500. Among the layoffs were most of the golf maintenance staff.
“It took me back to high school when I worked on a small golf course,” Jeffreys said. “We learned how to overcome a lot of obstacles during that period of time.”
By June 1, 2020, some staff returned to work, but numbers still weren’t up to pre-COVID levels. He said he had about 25 people on payroll in November 2021 – still short of normal – “but we’re definitely more fortunate than we were a year ago.”
Jeffreys began working at Pinehurst as an intern while in university and worked his way up the ladder, becoming an assistant superintendent in 2006 at the No. 2 course, and then taking on the superintendent’s position. His first notable experience at the No. 2 course was working the 2008 U.S. Amateur. He also played a key role in the 2010-2011 Coore-Crenshaw restoration project.
“To be part of so many things at one facility was really a great learning experience for me.”
Jeffreys is a strong proponent of internships among turfgrass students on the cusp of graduation and entering the workforce. Internships allow students to learn other management styles, he said, noting that if they choose to return to their home club afterward, they will have another perspective on things such as other agronomic techniques.
Recalling his internship at Pinehurst, he said his strategy for competing against other interns was to outwork them, acknowledging that he wasn’t necessarily smarter than the competition. It was also important to never make the same mistake twice, he added.
While serving as an intern at Pinehurst, Jeffreys’ duties included syringing the bentgrass greens in the morning and cutting holes. While working with interns in his capacity as superintendent, he asks them what the club can do to help them along their career path
“It’s your career,” he’ll tell them. “What do you want out of it.”
Jeffreys will also assure his young charges that if they successfully complete their internship, they will pretty much be guaranteed a full-time job upon graduation – perhaps not at Pinehurst, but at another club.
Print this page