Thursday, September 16, 2010

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. 


4 comments:

  1. Clear and concise explanation Matt. Thanks! Can we either get to all rye or all bermuda? Are the new bermuda hybrids more winter tolerant?

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  2. We can get to one turf species but which one is the question. I suspect this will be a conversation at Granite Bay moving forward.

    What you have heard is right regarding the newer bermuda grass species. They are more cold tolerant allowing them to hold onto color longer and come out of dormancy much earlier and quicker.

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  3. MATT - I HAVE SIMILAR ISSUES ON 100% BENTGRASS. WHAT HAVE YOU FOUND IS THE BEST WAY TO DRY OUT THE WET BENT THATCH WITHOUT CREATING A MILLION HYDROPHOBIC AREAS?

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