Why We Get Soft In The Summer

We have been getting comments from members recently regarding golf course conditions mainly pertaining to wetness and / or softness of the playing surfaces. Admittedly at this time of year  the moisture level in the fairways can be  up and down from day to day and even morning to afternoon on any given day. There can be many causes from sprinkler heads that stick during the evening, a leaking irrigation pipe or a miscalculated irrigation program. Some are outside the realm of control and planning and some we have to continue to work on and improve.  That being said the softness that seems to historically accentuate at the end of the summer comes from two primary culprits. Firstly the heavy decomposed granite soil type that our turf is growing on, and secondly the cool season turf blend we currently have established.




Different shades of green reveal examples of different patches of Bentgrass & Ryegrass on #4 fairway.



Light grey / green large patches - Bentgrass
Darker green - Ryegrass #4 fairway

Our fairways at Granite Bay are composed of an approximate 50/50 mix of bentgrass and ryegrass. These turf types are not necessarily blended together but have developed into independent "patches" of the varying species of turf woven throughout the course. To review, the course was originally seeded with ryegrass in 1994 and bentgrass was inter seeded shortly thereafter in 1995. The thought of original ownership regarding the bentgrass inter seeding was that it was a superior surface to ryegrass and would be unique to our area giving the club an competitive advantage. The conversion from Rye to Bent was not immediate and  when ownership changed in 1997 to Club Corp along with turfgrass management strategies the bentgrass was still spreading.

Ryegrass patch (red flag) adjacent to Bentgrass (white flag) #4 fairway.
Notice the gray green color of the Ryegrass area as it is starting to stress out.
( Cross section photos below are from these areas)

The main problem with managing these two cool season grasses  together is that the water management and  thatch development are very different for both species.  Bentgrass in our climate can be watered deeply and infrequently along with requiring more cultural practices (aeration & de thatching) to control thatch. Ryegrass needs nightly watering in the summer but does not develop as much thatch and hence does not get as soft as a bentgrass surface. Bentgrass is more heat tolerant in our area and tends to hold up to traffic better then ryegrass but again a ryegrass surface is generally firmer despite it's higher irrigation requirement. Trying to maintain these two species literally side by side is difficult and this difficulty culminates at summers end in the way of  soft playing surfaces in the bentgrass areas  and drought & heat stressed ryegrass areas.

Bentgrass cross section with 3" thatch layer #4

Bentgrass thatch layer moisture holding capacity #4

Ryegrass cross section. Minimal thatch and dry #4.

Close up view of a ryegrass patch #4 fairway

Comparing our fairway surfaces in the summer to some of the warm season or bermuda surfaces in the area is not proportional. Eight months out of the year the fairway surfaces at Granite Bay are comparable and at times can be superior. Four months out of the  year the bermuda fairways of say Cata Verdera or Northridge, as  examples, will be firmer  and you will get more ball roll. Dormant bermuda in the winter and spring can be a suitable playing surface although not as aesthetic. However in a wet year, the dormant surface can be sloppy and impassable with carts. All of the turf species grown in this area, both warm season (bermuda) or cool season (bentgrass & ryegrass) have their definitive ups and downs.
 Last year as an example when we tried to lean a little more on the dry side we experienced an unacceptable level of turf loss and dry spots without significantly firming up the bentgrass areas. With that in mind we decided to go in yet another direction with irrigation management this year and water less with our automatic system at night and have  dedicated afternoon water staff to both hand water hot spots and cool heat stressed turf down in the late afternoons. We continue to  make daily targeted adjustments to our irrigation regimen in addition to the dedicated hand watering program and I actually feel good about the direction we are going.

Typical drought stressed ryegrass patch adjacent to a bentgrass patch 2009 #17 fairway



However your perception is our reality and our desire is to provide the fast and firm conditions you want. The current unique blend of turf in our fairways make these goals a challenge but we will not give up. All of us are living in trying economic times and the short term reality for Granite Bay's turf is to work with what we've got. Long term  there are options to contemplate, nevertheless remember there is no perfect turf species for this area and even if there were the  living & dynamic nature of this outdoor surface we play this great game will vary from season to season by default. 

Cart Traffic On Stressed Turf - How you can Help

The article above outlines one of our largest challenges in maintaining the turf here at Granite Bay. As I mentioned above we do daily targeted irrigation adjustments which includes turning irrigation off  in some targeted areas for multiple days to dry out the bentgrass. When we do this it stresses out the ryegrass patches in the afternoon until they get some hand watered. The labor intensity of handwatering does not always allow us to get to every ryegrass spot every day.



Ryegrass area in afternoon stress surrounded by bentgrass



Typically when this stress occurs and receives irrigation from handwatering or the automatic system that coming evening it rebounds adequately until the next afternoon. This situation can be prevalent all summer but particularly acute late summer early fall as the bentgrass thatch (sponge) has become saturated and we attempt to dry the course out.



Another stressed out traffic area in the rough on #12 in the afternoon



Again these areas will revive but in this weak state cart traffic can be very detrimental. This is where you can help. Recognize these areas by their grey / brown color  and do not drive on them with golf carts. The tracking can last for weeks and can be very unsightly. We have all seen it.



Cart Traffic damage on a section of turf that is being nursed back. The tracking remains for weeks

This is an area where the membership can really help. Not everyone reads these updates so if we spread the word to our fellow members we can really minimize some  ugly damage.

Drive on the Green - Stay away from the Grey  is the rule of thumb. If anyone can come up with a better catch phrase then that, lunch is on me.

Fall Aeration Schedule

Fall is just around the corner and with it comes aeration. We've done enough talking about excessive thatch and its detrimental effect on our playing surfaces and this is our oppurtunity to do something about it. Core aeration's is one of the best ways to deal with excessive thatch. Not only does the mechanical removal dilute the accumulation, the air added to the soil via the process creates a healthy environment for the soil where soil microbes can do their job and help degrade the thatch itself.

The removal process is disruptive as we all know so we want to keep everyone informed as to the what's and whens of this fall's aeration. Below is a schedule of what we will be doing. We have naturally come up with plan to work around the events coming up at the end of September.


                                        Granite Bay Golf Club Fall 2010 Aeration Schedule

Week                              Process                                                        Comments

August 30 - September 3           Start Core Aerating Rough                                              Get started on an area that will not
                                                                                                                                          effect events late in September


September 6 - September 10      Overseed  bermuda tees & approaches                         For effective overseed we cant wait till
                                                                                                                                          mid October.


September 13 - September 17     Continue Core Aerating Rough                                      Minimal effect on Events


September 20 - September 24     Continue Core Aerating Rough                                      Minimal effect on Events


September 27 - October 1          Continue Core Aerating Rough                                       Minimal effect on Events


October 4 - October 8                Aerate Putting Surfaces                                                   1/2" tines on 1-1/2 x 1-1/2 centers


October 11 - October 15            Core Aerate & De-thatch Fairways                                Afternoon procedures

October 18 - October 22            Core Aerate & De-thatch Fairways                                Afternoon procedures


October 25 - November 5           Core Aerate Green Surrounds                                        Time consuming, tedious work

Putting Surface Soil Testing Completed

We recently had physical soil testing done on three of our greens to help determine the cause of the isolated setbacks we had this summer. The greens tested were #7, #3 & #12. Seven and Three were tested because of their chronic year to year mediocrity in the summer months, and twelve was sampled as one of our healthier greens.

The testing did not reveal anything we did not already know but did provide scientific validation of how we need to move forward to provide the consistent, firm and fast putting surfaces you desire. As I have explained in previous updates, the bottom line is we have excessive organic matter or thatch accumulation in the top two inches of our putting surfaces  needs to be removed by more aggressive core aeration and deep vertical mowing. The good news is that the USGA greens mix below the top three inches is what should be expected with 16 year old greens and should be able to sustain a healthy surface once we get caught up with thatch removal.

The following are experts from the summary of the  ISTRC testing. As you will see they recommend  a minimum of 20% surface area displacement per year. We plan to target 25% to 30% for the next couple of years to get caught up. Good news is we can accomplish this using smaller 1/2" holes in a tighter pattern rather then using the larger 5/8" holes which take longer to recover. More details on how we plan to accomplish these goals to come.

"All three tested greens have an accumulation of plant-deposited organic matter & thatch within their upper 3 to 4 inches, which is the source of the high water holding & water porosity properties. Without open aerification holes we would estimate the root zone would support infiltration rates at or below 2 in./hr."

"A build up of organic matter and/or thatch is often a gradual process that occurs when the rate of plant-deposited biomass exceeds the rate of microbial decomposition and the physical removal through hollow coring & verti-cutting. As cumulative 1st tier organic contents (sum of the upper 4”) exceed 7 to 8 percent or 2 to 2 ½ percent, by inch, our testing & research has shown it becomes increasingly more difficult to keep the root zone open & breathing as well as maintain desirable firmness & green speed."

"Over the years we have been conducting an ongoing study into the annual displacement percentage and its impact on the aging of greens. Frequency has been a common measure of aerification; however with the wide range of tines & setups it provides very little information as to the true impact of aerification."

"Our goal through this study has been to establish a quantifiable measure for aerification and through its correlation to the physical properties help establish appropriate short & long-term programs. Given the current conditions, age of the greens, and their turf-type an excellent goal for your greens would be at least 20 percent annual surface area displacement (calculation based on the OD of the tines)."

 The newer aerifiers, quadtines, blocks, and deep verticutters have allowed many superintendents to significantly increase their annual displacement without increasing the frequency per year. For example, the Toro ProCore using 10 tine block and a ½ inch tine provides a good balance of displacement, ease of fill and recoverability."

"With greens that are prone to sealing off, it will be important that you also supplement the larger tine aerifications or deep verti-cuttings with regular venting using non-disruptive equipment such as the HydroJect, Planet Air, needle/pencil tines, hollow/solid quads, bayonet tines, star/cross tines, slicer, or deep spiker. Venting has proven to be extremely beneficial to the health of the turf and promoting gas exchange, particularly when done on a regular basis." "Improving the ability for the root zone to breathe will not only encourage a deeper, more sustainable root system but also enhance microbial activity to aid in the natural decomposition of the organic matter & thatch."

"The current testing has established an initial benchmark of your greens. We would recommend that you continue to monitor your greens with regular testing. The information derived from regular testing will allow you to monitor the aging process of the greens, evaluate the effectiveness of the current cultural practices, modify the program based on hard data, make adjustments to the program to meet the individual needs of specific greens, and detect problems before they affect the health of the greens."

Sincerely,

I.S.T.R.C.

by:

Matt Pulis, M.S.

Agronomist

Southern Blight Update

The Southern Blight infestation that we experienced primarily around green surrounds in July could have been much worse. However the below normal summertime temperature's in both mid July and August helped stop the disease threat, and actually allowed us to germinate cool season ryegrass seed which is normally a difficult thing to do in the summer.

As I explained in an earlier update, we treat around the greens preventively for this disease but conditions became favorable even with the protection. The weather change and another curative treatment allowed us to get the pathogen under control and the unseasonable weather facilitated recovery sooner rather then later.

However some of the areas were close to greens and with the associated traffic along with the importance of the area we decided to re-sod the area. The areas we addressed with sod were #7, #10, and #17 greens. We still have a patch to do at the right bunker on #4 and we will address that next week.

Southern Blight area behind #2 green early July

Recovery of the same area mid August