Red Rocks Country Club Morrison, Colorado Visit Date: May 27, 2020 Present:

Ron Creech, Club President Dennis Sullivan, Golf and Greens Chair Linda Joyce, Golf and Greens Member Alana King, Golf and Greens Member Tom Pirog, Golf and Green Member Craig Ramirez, Board Member Ron Rottmann, General Manager Bobby Norman, Interim Golf Professional Aaron Smith, Superintendent Kevin Atkinson, Golf Course Architect Brian Whitlark, USGA Green Section

United States Golf Association Brian Whitlark, Agronomist | Green Section | West Region 3677 E Turnberry Ct. | Gilbert, AZ | (480) 215-1958| bwhitlark@usga.org

The USGA Green Section develops and disseminates sustainable management practices that produce better playing conditions for better golf.

C O U R S E C O N S U L T I N G S E R V I C E

Onsite Visit Report

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Executive Summary

Thank you for the invitation to return to Red Rocks Country Club to conduct a Course Consulting Service visit on behalf of the USGA Green Section. About six weeks ago, USGA agronomist Cory Isom and I had a conference call with the club leadership and discussed methods to help encourage recovery from winter damage. It is great to see that now, in late May, the majority of that damage has recovered very nicely. There are some remaining scars on several putting greens and fairways, and these areas will continue to improve with the onset of warmer temperatures. It was also great to see the health of green Nos. 1 and 14 that were seeded to T1 creeping bentgrass in September 2018, and are now open for play. We also were able to closely observe the new sodded greens on Nos. 10 and 13 which will be ready for play next week. The majority of our discussions during this course tour focused on putting greens and the topic of renovation. However, we did spend some time on fairways and briefly discussed bunker renovation. A brief summary of those topics is included below:

• Putting greens. The topic of renovation on putting greens is at the forefront of the discussions among the club, and in we will discuss several options for regrassing greens and improving the root zone in this report. We will also discuss strategies to mitigate winter damage.

• Fairways. Damage to fairways from winter desiccation and extended ice coverage was a bit of an anomaly this year. In the fairways section of this report, we will discuss methods to expedite recovery, recommend additional equipment to remove snow in the late winter and early spring, and continue with sound, fundamental agronomic practices such as aeration and sand topdressing.

• Bunkers. Bunker renovation is looming on the horizon for the club, and we will briefly discuss bunker liner options and a few key design elements such as maximum slopes and grass bunker faces that are less labor intensive to maintain.

Table of Contents

Putting Greens ......................................................................................................................... 3 Observations .............................................................................................................................. 3 Recommendations ..................................................................................................................... 5

Fairways ................................................................................................................................... 9 Observations .............................................................................................................................. 9 Recommendations ................................................................................................................... 10

Bunkers .................................................................................................................................. 11 Observations ............................................................................................................................ 11 Recommendations ................................................................................................................... 11

Conclusion ............................................................................................................................. 12

Additional Considerations .................................................................................................... 12 USGA Green Section Record ................................................................................................... 12

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Putting Greens

Observations

1. Winter Damage

We did observe some winter damage to the Poa annua putting greens. Most notably, the larger damage was observed on the low-lying areas on green Nos. 2 and 7, and these areas were clearly impacted by shade from trees. Other damage was observed on green Nos. 3, 4 and 5 which are prone to winter desiccation due to wind exposure.

2. Shade and Exposure

The greens that are shaded by trees located east, southeast and south of greens are at higher risk of winter damage and delayed recovery in the spring. Examples include No. 2 and No. 7 greens where there are trees in close proximity to the greens and located southeast or south of the green that cast more shade in the winter months due to the low angle of the sun this time of year.

3. Varied Soil Profiles

There is a wide variance in the rootzone supporting the greens. This variety of rootzones creates inconsistency with regard to playability and aesthetics, and Mr. Smith and the agronomic team are faced with managing different rootzones that have different infiltration rates and water and nutrient retention.

It appears that crown hydration (grass cells bursting from freezing) occurred in low-lying areas on No 2 (left) and No. 7 greens.

Green Nos. 3 (left), 4 and 5 (right) have some small scars left from winter desiccation (drying) damage.

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• The greens that were built according to the PURR-WICK system include Nos. 2, 8, 9, 10, 11, 12, 13, 15, 17 and 18. It appears the rootzone is similar among these greens. The soil texture varies with depth. These greens are poorly drained and due to the “bathtub” effect from the PURR-WICK system, there is black layer present in many of these greens in low-lying areas. Green Nos. 10 and 13 were sodded to T1 bentgrass four and a half weeks ago. The greens were enlarged during the sodding process and a perimeter drain (often referred to as a “smile drain”) was installed at the low-lying area of the green. However, no modifications to the soil profile were made.

• The second category of rootzone appears to be fairly consistent on green Nos. 3, 4, 5, 6, 7 and 16. Although these greens were not built at the same time, it appears they were built from 1998 to early 2000s, and soil profiles collected during the course tour revealed the rootzone characteristics appear to be quite similar. While there is organic matter accumulation in the top 3 to 4 inches of these greens, it appears the original sand used remains intact and appears to have good physical characteristics.

• Finally, green Nos. 1 and 14 were rebuilt to USGA recommendations about 18 months ago and seeded to T1 creeping bentgrass. A profile from No. 14 green revealed roots extending well beyond the 7-inch depth and very likely, roots extend to 10 to 12 inches.

A profile collected from No. 10 green (left) shows the stratified layering in the rootzone. The light- colored sand at the surface was introduced with the recent sodding. The profile on the right shows the rootzone in No. 15 green. The layers are similar, minus the light sand layer at the surface.

(L) This image of the rootzone on No. 16 green is representative of greens 3-7 as well. The rootzone appears to exhibit good physical characteristics beneath the zone of organic matter accumulation (the darker area in the top 3 inches). (R) No. 14 is a perfect example of a rootzone with desirable physical characteristics – no layers and a consistent, homogenous soil with excellent drainage and porosity.

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4. PURR-WICK Greens

Profile samples collected from the PURR-WICK greens generally indicated anaerobic conditions and black layer. Although reports were that the front of No. 15 green has improved, if there are any improvements, they are minimal.

5. Numbers 10 and 13

It was good to see the sod was of good quality on green Nos. 10 and 13 and the greens exhibit a healthy mat depth that exhibits good sod strength. It is also good to report that the greens have rooted very well into the existing rootzone. We did observe that in the green expansion areas, there is some scalping and generally weaker turf along the perimeter of the greens.

6. Numbers 1 and 14

While we did not have time to stop on No. 1 green, we were able to collect a soil profile from No. 14 green. The health of this T1 bentgrass was impressive, and reports are that similar health can be found on No. 1 green. We observed a mat depth of approximately 3/4 inch on No. 14 green, and the key moving forward will be to manage surface thatch and organic matter. We also observed some wide-bladed and laid-over bentgrass and recommendations will be provided below to improve the surface quality of the greens.

7. Exposed Greens

Green Nos. 3 through 6 and especially Nos. 4 and 5 are more exposed to the strong winds during the winter months and winter desiccation is a real concern. Mr. Smith and his team have implemented various strategies to mitigate desiccation, but it is clear that some alternative options need to be considered moving forward.

Recommendations

1. Greens Renovation

To achieve consistency and offer the greatest potential for success for the next 30 to 40 years on these putting greens, it would be best to rebuild all greens other than Nos. 1 and 14. Although this option will create the greatest disruption and is the most expensive option, it would put the club in the best position moving forward. The membership has had to deal with some form of construction essentially every year for the past few years, and it would be best to install some quality, temporary greens and deal with construction for one year then move forward with greens construction in the rearview mirror. Greens rebuilding should be strongly considered; however, comments during the course tour seem to indicate that the membership may not have an appetite for this level of disruption and may not have the funds to consider this option. Therefore, we will consider several other options. Options will include modifying the rootzone, and a lesser invasive option which would include removing the plastic along the perimeters of the PURR-WICK greens and resodding.

• Modify the rootzone. A potential option is to modify the rootzone in the greens, and focus would be placed on the PURR-WICK greens. The first step is to collect a soil core from two to three PURR-WICK greens and one or two of the greens built around 2000 such as Nos. 3 through 7 and submit to a soil physical testing laboratory for analysis.

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It is recommended to reach out to Mr. Sam Ferro at Turf & Soil Diagnostics in Linwood, Kansas, to consult with prior to collecting the undisturbed core samples. Once you have the results from these tests, please forward to my attention, and we can discuss the appropriate measures moving forward.

Based on the test results, there will be several options for modifying the rootzone of these two different types of greens to improve infiltration and porosity. However, the tests may reveal that there is no practical method to improve the rootzone in the PURR-WICK greens. It is more likely that the newer greens could be modified to more closely resemble the new greens construction on hole Nos. 1 and 14.

• Least invasive option. The least aggressive option to regrass greens would include locating and removing the plastic in the PURR-WICK greens around the perimeters. Removing this plastic would help escape subsurface water from the greens. However, this option would not improve the rootzone characteristics. The existing sod could be removed from greens, aggressive aeration practices employed, and a small band of sand applied prior to sodding with bentgrass. I must emphasize that this is the least desirable option, and I am concerned about the future of green Nos. 10 and 13 without modifying the rootzone. The potential for turf decline on these greens is significantly greater than on green Nos. 1 and 14 due to substantially different drainage and porosity characteristics.

2. Organic Matter

Organic matter management on all greens, especially the newly sodded and newly seeded greens, is critical. The primary method to dilute surface organic matter is with sand topdressing.

• Approximately 2,200 to 2,500 pounds of sand per 1,000 square feet should be applied on an annual basis.

• It would be wise to plan on at least two heavy sand applications per year in spring and fall with rates of 400 to 500 pounds of sand per 1,000 square feet.

• The remainder of the sand will have to be applied during routine sand topdressing events. Given that routine sand topdressing is typically applied between 50 to 100 pounds per 1,000 square feet, you can see that it is essential to apply the sand on a frequent basis, as often as once weekly. With that in mind, it is strongly suggested to delay tee times by two to three hours one morning per week to allow Mr. Smith and his staff to conduct this important practice ahead of play.

3. Aeration

Continue to conduct two aerations annually on the older greens and consider one annual aeration event on the newer greens such as Nos. 1 and 14. Given the thatch accumulation in the 19th green, it is suggested to conduct two aerations annually on this green.

• On the older greens, it is essential to conduct deep tine aeration, and we discussed an additional practice that has proven results to improve drainage characteristics of poorly drained greens using the Drill & Fill® machine. The Drill & Fill machine would only be necessary on the PURR-WICK greens. Ideally, this practice would be employed once annually, but at the very least, if the budget does not permit, conduct every other year.

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4. Putting Green Expansion

We discussed expanding the right side and back, left portion of No. 16 green. In the areas for expansion, conduct aggressive aeration, making two to three passes with core aeration across these areas.

• Aggressively scalp the areas as low as the mower can go, making multiple passes to achieve the smoothest possible surface. Hand brush the areas to stand up the existing turf and follow with multiple mowing passes.

• Apply generous amounts of sand to continue to smooth the surface and dilute surface organic matter.

• Roll extensively to firm and smooth the surface. An asphalt roller works well.

These aggressive practices will obviously create an area that is unattractive during the recovery process and it will be important to communicate to members that this short-term disruption will ultimately yield an expansion area that more closely matches the interior of the greens. Ideally, this practice would be made in the spring when temperatures begin to increase and are favorable for turfgrass growth.

5. Numbers 10 and 13

Given that the sod strength and rooting are good on the newly sodded No. 10 and No. 13 greens, it is recommended to move forward with opening the greens June 1.

• It is recommended, however, to adjust the green perimeter to move in approximately 3 feet compared to the current mowing line given the slope. Currently, the slope is too severe to mow at putting green height and scalping has already occurred. It is suggested to increase the mowing height to approximately 0.200 to 0.225 inches and maintain as a green collar.

• It will be critical to conduct routine venting practices on these greens approximately every two weeks throughout the entire season using small-diameter venting tines.

6. Numbers 1 and 14

Utilize venting practices on Nos. 1 and 14 throughout the season on a routine schedule. It will also be critical to increase sand topdressing to avoid excessive organic matter accumulation at the surface. We also discussed increasing surface management practices such as brushing and grooming.

• Set the grooming blades approximately 0.010 inches below mowing height. The goal with the grooming blades is to cut horizontal leaf blades, but visible lines should not be visible following grooming.

• You are also encouraged to utilize vertical mowing with blades set slightly above zero in a nonaggressive fashion.

• You may consider conducting one annual core aeration on these new greens in the spring using 3/8-inch diameter tines on a tight spacing.

• There is also the option to manage these greens without any core aeration and rely on venting practices and frequent sand topdressing to dilute organic matter. During our next visit, it will be wise to sample for surface organic matter to quantify the organic matter percentage in the top 2 cm of the greens and continue to monitor this over time, which will help direct sand topdressing and aeration practices moving forward.

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7. Numbers 2 through 7

Continue to seed these greens, and consider purchasing the “job saver” tines which are useful to create small depressions in weak areas to encourage seed germination and maturity.

• It is important to note here that it is always very difficult to germinate and mature new seed while maintaining the greens in play. Larger areas of damage such as on Nos. 2 and 7 should be sodded, and we discussed using sod from the chipping green.

• We also discussed mixing fine fescues such as a chewing fescue with the bentgrass seed, given the faster germination of the chewing fescue which will act as a nursery crop and aid the bentgrass maturity. Dr. Leah Brilman from Seed Research suggests using either straight Chewings fescue or add in slender creeping red fescue (critical if salinity is an issue). This blend can be used to repair greens, tees and fairways, whether bentgrass, Kentucky bluegrass or Poa annua.

8. Nursery Green

We discussed that it would be an excellent idea to construct a new nursery green for Poa annua and bentgrass immediately adjacent to the No. 10 tee complex. This would be a great addition to the facility.

9. Poa annua Control

It is recommended to begin utilizing PoaCure® on the 19th green this fall. Utilize three to four applications in the fall at the recommended label rates. A fact sheet on the use of PoaCure has been included with this report for your reference. It is not recommended to use PoaCure on any other greens for now.

10. Mitigating Winter Damage

Mitigating winter damage on greens will include a combination of strategies including tree removal and considering covers for a few of the wind-exposed greens.

• We also discussed the option of installing frost-free hydrants on green Nos. 3, 4 and 5, potentially tapping into the potable water system.

• We discussed tree removal on green Nos. 2 and 7. Images of suggested tree removal are included below.

This area adjacent to No. 10 tee complex would be an excellent site for a large nursery green divided into a Poa annua and Bentgrass green.

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• To improve the health of greens going into winter, begin raising height of cut, with the ultimate goal of approximately 0.140 to 0.150 inches on the prism gauge. Continue to run deep irrigation cycles on greens to wet the entire rootzone to help discourage desiccation.

• We also discussed using Civitas™ on the Poa annua greens, with three to four fall applications spaced two to three weeks apart. The Civitas has proven to expedite Poa annua recovery if under extended periods of ice cover.

• It is recommended to use permeable covers on green Nos. 3, 4, 5 and 6 during the winter months. The covers will likely need to be removed when temperatures exceed 55 degrees during the winter to avoid overheating the turf and therefore there must be access to the covers all winter. It is not recommended to cover greens such as Nos. 2 and 7 that experienced crown hydration damage. The permeable covers will not help this situation.

• Finally, be certain to utilize a wetting agent all the way up into the late fall months to discourage any hydrophobic effects.

Fairways

Observations

1. Winter Recovery

During our conference call about six weeks ago, the primary topic was the thin, weak turf that was damaged coming out of winter this year on fairways. It was good to see that in late May and with the onset of warmer temperatures, the turf is recovering nicely. It was also good to see perennial ryegrass germination in the damaged areas. Although there are a few scars left, for the most part, the fairways have healed and there is good playability.

We discussed removing this pine tree that is in close proximity to No. 2 green and located southeast of the green, casting shade in the late fall, winter and early spring months, delaying recovery

It is recommended to remove two of the three pine trees immediately behind No. 7 green to improve sunlight exposure and expedite spring growth.

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• In my travels to high-elevation courses, damage on fairways is typically associated with highly shaded areas and turf on north-facing slopes and low-lying areas that are poorly drained.

• At Red Rocks, there was no clear pattern to the damage in fairways, although we did observe some damage associated with north-facing slopes on fairway Nos. 10 and 11.

• There clearly was a combination of factors that led to the damage, some of which can be related to water, either too much in low-lying areas with extended ice coverage or in other areas, with deficit water leading to desiccation.

Recommendations

1. Ryegrass Seeding

Experience with seeding ryegrass and Kentucky bluegrass into existing turf stands has revealed that the success rate for Kentucky bluegrass is minimal at best. Therefore, it is recommended to continue seeding ryegrass through interseeding.

• We also discussed using fine fescues for fast germination, and an argument can be made that the fine fescues would offer an increased level of hardiness during the cold-weather months. While this is worth experimenting with, experience has shown that the ryegrass and Poa annua will eventually dominate and the emphasis should continue to be placed on seeding ryegrass.

2. Aeration and Sand Topdressing

The fairways do contain a significant thatch depth, which leads to hydrophobic conditions and desiccation. A combination of multiple aeration events, vertical mowing and sand topdressing must be continued to reduce the thatch level.

• Utilize some form of aeration including hollow tines, solid tines, deep tines, and shallow slicing events six to eight times per year to improve water infiltration and cut through the thatch.

• Continue to utilize sand topdressing at fairly light rates on most holes, but as discussed in previous reports, sand should be applied aggressively on hole Nos. 4 and 5.

3. Fall Preparation

In the fall, it will be essential to make several wetting agent applications to help improve moisture consistency across fairways. Similarly, use deep irrigation cycles to wet chronically dry areas and improve moisture consistency.

4. Snow Removal

At times, snow removal is essential to exposed turf that has been suffocating from extended ice coverage. Additionally, snow removal can be an excellent practice to expedite recovery and growth in the spring months. It is recommended to add a blower to the Ventrac® mower you have, and consider adding a snowblower to a tractor for more efficient snow removal in the spring months.

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Bunkers

Observations

1. Future Plans/Current Condition

It was reported that a bunker renovation is forthcoming for Red Rocks Country Club. We can discuss specifics with bunker renovation as the project nears, but in the recommendations section below, we will discuss some liner options and tips to adjust slopes on bunkers to improve ingress/egress for golfers and minimize labor inputs.

Recommendations

1. Bunker Liners

While lining the bunkers at Red Rocks will be useful, it will be important to modify the liner in the low-lying areas in order to avoid chronically wet sand in bunkers.

• Over the past five to six years, the industry has seen the effects of the perched water table at the sand and bunker liner interface, which results in chronically wet sand in low-lying areas, especially during summer months when irrigation is frequently applied.

• There are several methods that are now being used to overcome the challenges associated with the perched water table. The most promising I have seen is a method in which the drain lines are placed on top of the liner. Two examples are provided below.

2. Bunker Slopes

At many private clubs with aging member populations, ingress/egress in the bunkers is a significant concern. Therefore, the bunker renovation should be completed with ample entry/exit points with minimal slope both for golfers and for the riding bunker rake.

• For bunker slopes, it is strongly recommended to avoid any slopes that exceed 30 degrees. This will help maintain sand on bunker faces and reduce erosion potential.

The Bunker Solutions™ product uses white synthetic turf and the drainpipe is placed on top of the liner, followed by filling the entire cavity with sand. On the right, drainpipe is placed on top of Capillary Concrete™ liner, again to provide free drainage from the top of the sand to the drainpipe.

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Conclusion

It was great having many members and golf staff join us during the course tour, and the members raised some excellent questions. Thank you for a productive and enjoyable course visit to Red Rocks Country Club and for your continued support of the USGA Green Section. I will follow up with Mr. Smith to review the results of the putting greens physical tests once they are available. Best wishes for a successful summer season, and please do not hesitate to contact my office should you have any further questions or concerns. Respectfully submitted, Brian Whitlark, Agronomist USGA Green Section Distribution:

Aaron Smith, Superintendent

Additional Considerations

USGA Green Section Record

If you would like to receive the USGA’s electronic publication, the Green Section Record, click here. It is free, informative and sent directly to you via email every two weeks.

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About the USGA Course Consulting Service

As a not-for-profit agency that is free from commercial connections, the USGA Course Consulting Service is dedicated to providing impartial, expert guidance on decisions that can affect the playing quality, operational efficiency and sustainability of your course. First started in 1953, the USGA Course Consulting Service permits individual facilities to reap the benefits of on-site visits by highly skilled USGA agronomists located in Green Section offices throughout the country.

For questions regarding this report or any other aspect of the USGA Course Consulting Service, please do not hesitate to contact our office.

*PoaCure proposed name and state registrations pending as on March 25, 2020 and a registered trademark of Moghu Research Centre. Reference and read label for all use directions and restrictions.

The information provided is intended for general educational purposes only for USGA Course Consulting Service Customers. It is not an express or implied guarantee or warranty of performance, condition or results. Always follow label recommendations and instructions. Product references, if any, are not sponsored by or endorsed by the USGA.

Methiozolin on turfgrass

• New class of chemistry, isoxazolines • New HRAC Classification – Q • Chemical is relatively insoluble in water,

similar to simazine (3.4 mg/L) • Labelled for creeping bentgrass and

bermudagrass golf course greens and other turfgrass areas

• Pre- and postemergence active on annual & roughstalk bluegrass

• Seedhead suppression of Poa annua when applied at flowering

• Preemergent control of crabgrass, goosegrass and assorted BLW

PoaCure Use Directions

• Apply PoaCure alone, 0.6 to 1.2 oz/1000 ft2, every 2 to 3 weeks o Some Poa biotypes more sensitive than others- use

low (or half-rates) for first 2 applications to gauge response

• Small-scale test broadcast applications are recommended prior to widespread use, start with low rate, 0.6 oz/1000 ft2

• For postemergence control, sequential applications may be required (30 days apart)

• Resistance Management - Utilize other herbicides, growth regulators, with different modes of activity to minimize resistance o Other products should be applied separately, not as a

tank-mix with PoaCure o To minimize potential for injury, these should be

applied no sooner than 2 to 3 weeks after the last PoaCure application

o For assistance in developing a resistance management program for Poa annua control, contact your USGA Green Section agronomist

Tips for Success

• Product can only be purchased directly from the Moghu, online

• Avoid applications to stressed turfgrass or under environmental stressed conditions

• Do not apply to weak or thin turfgrass especially if roots are compromised or when shoot/root growth is minimal (cold temps)

• Varietal turf sensitivity can vary, do not apply to colonial, velvet bentgrass

• Root active – weed uptake requires irrigation after application (0.2 – 0.25”) and water volumes >1.5 to 2 gals water/1000 ft2

• Preemergence activity superior to post activity. Slow acting, and may require multiple applications

• Avoid tank mixes with fungicides, herbicides or any other products except trinexapac-ethyl

• Fall applications observed to be most efficacious but also most potentially injurious to greens turfgrass

USGA Green Section

PoaCure®* (methiozolin) – golf course herbicide guidance document