Pinnacle Peak Country Club uses fans in the summer season to help the golf course's 007 bentgrass greens succeed in the desert climate. Photos courtesy of Cody Horstman.
Pinnacle Peak Country Club is a private golf club in Scottsdale, Ariz., and home to a golf course that defies desert climate norms. With the average air temperature in the summer ranging from 100-115 degrees, most of the surrounding courses at similar elevation (1,750-1,940 feet) have different strands of ultradwarf bermudagrass as their putting surfaces, but not Pinnacle Peak.
Pinnacle Peak is already unique to Scottsdale, as it is a tree-lined, parkland-style golf course rather than the desert golf landscape common to the Phoenix metro area. When I started in 2014 as the director of agronomy, I knew PPCC had a special course. I also knew something needed to change with the Crenshaw greens, which had 20% bermudagrass infestation. A colleague in the area told me that as the elevation climbed north of Pinnacle Peak Road in Scottsdale, bentgrass greens could be successful. Unfortunately, I was on the south side of Pinnacle Peak Road.
Many greens on the PPCC golf course are surrounded by trees and oleander hedges that caused shade issues and stagnant air conditions. The collars were Tifdwarf bermudagrass and were grown half on the native surrounding soil and half on the greens’ cavity. This created inconsistencies, along with severe loss on the greens every summer that led to repetitive sod repairs. All in all, there were some challenges.
Through ISTRC testing, we discovered the current sand base on the greens did not meet USGA-build recommendations. The sand tested around 7% in the very fine category, with a heavy layer of calcium carbonate built up above the pea gravel blanket. Additionally, we found 12 of the 18 greens did not daylight-drain but were bubbler drains that were causing the water to back up into the drainage system under the greens.
The summer stress period lasts from July 1 to Sept. 15 each year. Soil temps range from 80-90 degrees overnight and 95 to 105 during the day. The surface temperature averages between 100 and 115 degrees during the day with dew points of 60 to 70 degrees, with desert air temperatures rising to 115 in the summer and humidity up to 60%. These persistent conditions for 24 hours a day and 12 to 16 weeks of the year posed a major challenge for the bentgrass. All these factors were taken into consideration when we went to the members of Pinnacle Peak with a proposed plan for the greens.
Pinnacle Peak Country Club's 15th hole before the renovation.
In April 2015, Pinnacle Peak Country Club voted to approve a complete core-out renovation of the greens. After long discussions with the membership, we decided to stay with bentgrass to evaluate whether the newly constructed greens would be successful before switching to an ultradwarf bermudagrass. Regardless of the turf selection, it was obvious the infrastructure of the greens needed to change.
We chose 007 bentgrass due to its cold-weather growth capabilities during peak winter season play, when the tee sheet is full of golf members ready to take on the course. The planning process began with architect Rick Phelps and Landscapes Unlimited, and construction began in May 2016, concluding that August.
The greens were built to USGA greens recommendations using 90% USGA-spec sand blended with 10% profile. All subsurface drainage was redesigned and installed with all exit drains extended as necessary to ensure each drain could be daylighted with no restrictions.
Between that August and December, the 007 bentgrass was grown in from seed. The greens were successful in the busy winter months, but July 2017 was the start of the real test. There were still challenges with the new greens, but they were far less severe. Summer 2017 was the perfect learning experience for our team to determine whether further steps were needed for the bentgrass to succeed.
In July 2018, Pinnacle Peak Country Club began the first trial with a fan acquired from Castle Pines in Colorado. This fan was an older Precision Air belt-driven fan that Castle Pines was no longer using. I could never thank Doug Brooks and Castle Pines enough for the assist at the time. The fan was installed on the third hole green. The third green is located next to the golf course maintenance building and is surrounded by hedges and trees, making it one of the most challenging greens to manage. We used the fan hoping it would help stir the air directly above the green and create an artificial evaporative cooling effect to provide the bentgrass some relief from the oppressive desert summer weather.
Infrastructure on the golf course of fan foundations, conduits, splice boxes and the fans themselves were performed by the golf course maintenance team at Pinnacle Peak. The team estimated they trenched and installed almost six miles of conduit for the project.
Within days of the fan’s installation, the putting surface saw a dramatic improvement. The membership decided to move forward with the fan experiment to additional challenging greens. After some research and reaching out to several sources, we selected the Turfbreeze fan from Subair Systems. This fan was a direct drive with variable frequency (VFD). These fans were much quieter and allowed us to speed up and slow down to meet the City of Scottsdale’s sound ordinance.
As the fan installation progressed through the course for the next several years, the greens continued to thrive in the summer months. Each year showed more promise, and each year we decided to install additional fans.
Not all locations were equal, and they posed different challenges each year. We worked annually with the City of Scottsdale for permits, approvals and planning. We also worked with a power company for engineering plans and designs. Additionally, we had to coordinate with the surrounding HOAs to tap into their existing power and coordinate bill-sharing. This project also required the use of directional boring to go under roads, through public easements and between private property with homeowners’ permission.
All the infrastructure on the golf course of fan foundations, conduits, splice boxes and the fans themselves was performed by the golf course maintenance team. This consisted of using a 12-inch auger and drilling the foundation holes 60 inches deep while pouring rebar-reinforced concrete footers for each fan. It was estimated the golf course maintenance team trenched and installed almost six miles of conduit at the conclusion of the project.
By summer 2024, every putting green at Pinnacle Peak Country Club had a VFD Direct Drive Fan from Subair Turfbreeze to preserve the 007 bentgrass greens. Pinnacle Peak CC is now the only golf course in the state of Arizona with fans on every green and a permanent in-ground infrastructure throughout the course.
Part of the build process involved drilling 60-inch-deep foundation holes using a 12-inch auger.
The PPCC agronomy team installs these fans every June, once our summer monsoon season begins, typically around the July 4. Once the dew points are consistently above 60 degrees for 72 hours, we will begin running the fans 24 hours a day. When the dew points fall below 60 degrees for about 24 hours, the fans will be shut off. The fans are connected to a Toro Lynx system and are run on switch programs that can be controlled remotely. Every fall by mid-September, the weather will begin to change, and the bentgrass will begin to thrive. Over the course of a week, prior to overseeding, the fans are removed from each green and put into storage for the next summer season.
After a several years of experimenting, brainstorming and going in a unique direction for the desert, the 007 bentgrass greens are doing well and have become sustainable during the stressful summer months. The fans have greatly reduced disease pressure, and the root depth density has increased. Root loss during the summer stress has been reduced, turf density has increased, ball marks heal faster, and bermudagrass encroachment has slowed due to healthier bentgrass.
In addition to the fans, we have added TDR soil moisture readers and POGO moisture readers, and Soil Scout in-ground sensors were added to our toolkit. The fans have added another variable of control when watering and keeping consistent appropriate moisture levels. There are countless victories that came along with this change, and they will continue to show over time.
The 15th hole after the renovation and the addition of fans to the greens.
Pinnacle Peak Country Club is now home to beautiful and sustainable 007 bentgrass greens and is believed to be the lowest-elevation golf course with this grass type in all of Arizona. Our membership and team took the fan concept, which had not been utilized in the desert, and found a way to achieve the goals and desires of our membership. Our approach to managing bentgrass over the past several years has now brought news that a few of the neighboring clubs are considering switching to bentgrass.
Regardless of the road we took, the best outcome is the satisfaction and enjoyment of our membership and their guests. This project was a long journey that required a tremendous amount of support from our membership. Based on the feedback we have been receiving, it was well worth it.
Cody Horstman, CGCS, is the director of agronomy at Desert Highlands Golf Club in Scottsdale, Ariz. He was the director of agronomy at Pinnacle Peak Country Club from 2015-2024. He is a 21-year GCSAA member.