USGA Regional Update

Deep Root Zone Modification In Fall For Better Putting Greens In SummerOCTOBER 20, 2017By Paul Jacobs, agronomist, Northeast Region

Drill-and-fill aeration is one of several options that can improve a putting green root zone profile beyond the capabilities of conventional core aeration.

Deep root zone modification of soil-based putting greens can provide significant, long-lasting benefits and mid to late fall can be a great time to do the work. Conventional core aeration practices typically affect the upper 3 to 4 inches of the root zone profile and may not fully address internal drainage issues. Over time, conventional core aeration performed at the same depth can also leave the underlying soil compacted. Implementing a program that targets deeper portions of the root zone profile can improve internal drainage, turf rooting and overall putting green performance. Putting greens with drainage systems tend to benefit the most from deep root zone modification.

Several options exist for deep root zone modification and each has its unique benefits. While one technique may be highly beneficial in one situation, it may not be the best choice for others. Consider the following options to supplement your conventional cultivation practices:

Drill and fill – This process drills holes up to 12 inches deep into a putting green on 6-inch centers, removing soil and backfilling each hole with sand to create deep sand columns in the root zone profile. The process can be labor intensive, but it infuses a significant amount of sand deep into the root zone profile that provides long-lasting benefits.

• Ideal applications – Putting greens with poor internal drainage – e.g., soil-based putting greens.

Deep-tine aeration – Most commonly this process is performed with solid tines that can penetrate up to 10 inches deep. Solid tines do not remove material but they fracture, loosen and alleviate compaction in subsoils that are not reached by conventional core aeration. Deep-tine aeration generally requires no cleanup and surface disruption is minimal.

• Ideal applications – Relieving compaction in all soil types. Perform deep-tine aeration during late fall to create open columns for drainage during freeze and thaw cycles.

Sand injection – Machines can use high-pressure water to inject sand into a putting green root zone profile. The sand channels created by this process often mimic the shape of a water droplet – i.e., narrow near the top and wider at the bottom. This method does not infuse sand as deeply as drill and fill, but it is faster and much less disruptive to the playing surface. Performing sand injection immediately after deep-tine aeration will help infuse sand deeper into the profile; however, no material is removed from the profile during sand injection.

• Ideal applications – Putting greens with excess organic matter in the upper 2-6 inches of the soil profile and soil-based putting greens with a shallow – i.e.,1- to 3-inch deep – modified root zone.

Each of these practices can improve putting green performance when used in the right situation, but they are not replacements for conventional core aeration. However, implementing one of the above practices can improve drainage and alleviate compaction deep within your putting greens. For more information about which option is best for your facility, contact your regional USGA agronomist.

USGA Regional Update

COURSE CARE

Dark And StormyJULY 7, 2017By Jim Skorulski, agronomist, Northeast Region

Ominous storm clouds signal an oncoming front and the potential for dangerous lightning.

Wet and soggy conditions have been common across most of the Northeast Region this season. Wet weather has saturated many golf courses and flooded others, disrupting maintenance and course-conditioning efforts. Fortunately, the wet weather has not severely affected turf conditions because temperatures have mostly remained moderate. However, continued wet weather combined with warming soil temperatures will reduce turfgrass rooting and could prove fatal. Turf managers are taking advantage of any dry weather to catch up on spraying and topdressing practices that have been disrupted by the rain. Hopefully the weather will also allow an opportunity to vent putting greens. Venting will help soils dry and re-establish gas exchange in the root zone. The USGA webcast, “Venting Aeration – A Benefit to Putting Greens,” further illustrates this popular cultivation technique.

Stormy weather patterns also bring concerns about lightning and the dangers it presents for workers and golfers. A properly functioning lightning detection system is the best defense against lightning. Lightning detection systems provide advance warning of incoming storms and let facilities know when conditions are safe to resume outside activities. However, not all golf facilities have lightning detection systems and there may be times when workers and golfers have to determine for themselves when it is time to seek shelter. Here are a few tips that workers and golfers can use when severe weather approaches:

1. The time between a lightning flash and thunder can be used to determine how far away the lightning strike occurred. Sound travels at a speed of about 1,125 feet per second (343 meters per second), equating to about a five-second count per mile (three seconds per kilometer) from the time of a lightning flash until the clap of thunder is heard. A count of 10 seconds between a flash of lightning and the clap of thunder means the lightning strike was approximately 2 miles away. Many were taught to count one second for each mile between a lightning flash and thunder, which greatly overestimates how far away the lightning strike occurred.

2. The “30/30 rule” is used by many to determine when it is time to head for shelter. The rule says that lightning poses a threat if it takes less than 30 seconds to hear thunder after a lightning flash and people should wait 30 minutes after a storm passes before resuming outdoor activities. The problem with the 30/30 rule is that the numbers are arbitrary. Using this method does not help to determine if a storm has sufficiently passed or if another storm is approaching. The best approach is to take cover as a lighting storm approaches and remain there until you are sure the storm has passed or until an all-clear signal is provided.

3. Lightning will often strike a tall object, but not always. Taking cover near smaller trees or objects hoping the lightning will strike a taller object may get you in trouble. Lightning can strike the ground or smaller trees, endangering anyone close to those areas. The only safe place to take cover from a storm is indoors or inside a closed vehicle.

4. Lightning never strikes twice is an old myth. Lightning can indeed strike the same spot multiple times if conditions are right.

July is also the time for field day demonstrations at Rutgers University and the University of Massachusetts. Field days provide an opportunity to see research in progress, to observe the newest grasses and to view the effectiveness of various control agents. Field days also provide an opportunity to interact with colleagues, which seems to be more and more difficult to do with everyone’s busy schedules. It is never easy to leave your golf course during midsummer, but try to attend one of the university field day events even if just for a few hours in the morning to support the university and gain valuable information that will make you a better manager. We hope to see you there.

Dear Members, 

As you know, over the past several months we have experienced a wide range of temperature swings.  These conditions enabled us to aerify the greens in January and have them covered immediately afterward.  This will allow our greens to recover sooner, providing for an early spring green-up period.  With our next aerification scheduled for August, golfers will have an excellent surface throughout most of the season. 

Aerating in the winter as we do allows us to do "core removal" at a time that will not interfere with the golfing season.  This process is very important to remove excessive organic matter near the top of the surface, creating greater breathing room for the turf and improved drainage.  This will keep the greens healthier and enable deeper root growth. 

It has been our strategy to aerify during the winter so that our greens are not disrupted with the aerification process during prime golfing season.  You might visit other courses at this time and see their greens in better condition than ours.  This means that they have chosen to aerify later in the spring.  While their greens may look good now, they will have a disruption in April or May, as all courses must aerify their greens.  Lakewood, on the other hand, will feel its pain early and reach prime golf season with its greens ready to go.  Aerating in the winter also puts little stress on the greens as the grass is mostly dormant during these times. With the climate we have during most summers - high humidity and heat - it's important to have a deep root profile.  Then, when we do have a drought, as we have in recent years at times, the greens are better able to adapt and not burn-out. The aerification we perform in August is done with small tines, loosening the soil and breaking up some organic matter while providing for air movement after a summer of play. 

In addition, removing the cores as we do in January, followed by covering the greens, enables the grasses to heal quicker than they would during traditional cold weather.  Of course, with the wide temperature swings we experienced in early March, we did remove the covers earlier than anticipated, exposing the greens to the warmth and sunlight, allowing them to heal faster. 

All in all, we anticipate having our greens in excellent condition early in the season and throughout the summer, with minimal impact on Members golfing enjoyment for greens conditioning. 

On other items across the grounds, we have installed curbs at select locations and we are allowing the grass behind the first green to grow higher, improving the turf and making it an easier walk from the cart path to the green.  We have also "deep-tined" all our fairways and approaches to the greens.  A light top-dressing of these areas will take place in April. 

Elsewhere, we are creating a new white tee on the eighteenth hole, lengthening it by approximately 30 yards.  We expect this to be completed by the end of March, followed by a few weeks of grow-in before opening it for Member play. 

However, a great deal of my staff's time was also spent assisting with getting the Club's new Air-Structure up and running.  We installed a new irrigation system for each court and aided the various contractors as needed to meet schedules. 

Our final steps in March will be going through our bunker prep process, cleaning the edges, checking for consistent depth of sand and adding as needed.  With over four acres of bunkers, this is a very time consuming process, but one which is important to maintaining a premier course.  We will also be adding sod at select areas in the short-game area.  Obviously, the amount of heavy traffic this area receives results in a very slow recovery time.  By adding new sod now, the short-game area will be in good condition when Members begin to use it in the coming weeks. 

Regards, 

Phil Desbrow, CGCS