Bentgrass and a Key Factor

The success and failure of the agronomic plan we implement at Arrowhead Country Club will always be linked to the dominance and percentage of bentgrass in our greens.  Greenway Golf's surface management philosophy has been critically scrutinized over the years due mainly to the lack of understanding revolving around the "non-industry standard" practices.  The approach considered by many as unique and secretive is not only successful, but environmentally conscious.  There are many factors that influence the success of this program, but I would like to address one of them in this posting:  Mowing Frequency.


We utilize daily, monthly, and annual task tracking to measure opportunities for reduction and calculate efficiencies on each specific property.  One commonality across the properties that are managed by Greenway Golf is the limited amount of greens mowing.  In 2011 on a weekly average, we cut the greens 2.67 days out of seven at Arrowhead Country Club.  To put it in perspective, most courses are mowing six to seven days a week with supplemental double cutting.
  
There happens to be a direct correlation to Bentgrass competitiveness and population and frequency of cut.  Seasonal variation and a Superintendent's management practices should influence the decision to mow or not and understanding the strengths and weakness of Bentgrass is key.  With sustainability and minimalism being hot button topics within the industry these days, it only makes sense to limit practices that negatively impact Bentgrass competitiveness.

The Buzz surrounding Royal Melbourne

As many of you viewed the recent President’s Cup at Royal Melbourne in Australia, did you notice the “unique” color associated with the greens?  The rich, deep green, almost purple hue is distinctly similar to the pigment reflected in the greens here at Arrowhead Country Club.

The color that has had the golf industry a buzz is the result of a ferrous sulfate (iron) application.  "High" rates of ferrous sulfate, a salt based fertilizer/soil amendment, will refine the leaf blade if allowed to dry on the tissue.  This provides obvious playability benefits from a surface management standpoint.  Ferrous sulfate also provides mild fungicidal benefits, acts as a herbicide, and acidifies the very top layer of the soil with repeated applications.  As a salt, it can act as a desiccant to any recently germinated seedlings and effectively control immature poa annua.  Studies have shown positive effects on root growth, recovery from drought stress, and increased wear resistance.

Foliar applications of FeSO4 promote a quick response and increase in leaf chlorophyll, thus green pigment within the leaves.  The rates we utilize as part of our agronomic program produce a deep green, almost purple hue when left to dry on the plant tissue.  This is very similar to what was witnessed at Royal Melbourne.     

Royal Melbourne

#1 Green (Post FeSO4 application)

#9 Green (Post FeSO4 application)

"Glass Like" appearance of #12 green

Chipping Green Transformation- Poa to Bentgrass

For those members that have been following the two year transformation/improvement program of the poa/bermuda chipping green to bentgrass, here are some photos.  This is a unique turfgrass transformation project for Southern California:  poa to bentgrass.  I'm sure that it has been attempted elsewhere in this region, but not with the success rate that we are achieving.

The chipping green was previously sodded bermuda grass to test if the species should be the turfgrass of choice for the greens after several years of failure in the mid 2000's.  After the loss of the greens in 2006, Greenway was hired.  Upon Greenway recommendation, the decision was made to sod the greens with T1 & A4 Bentgrass.  The decision to sod versus seed was made to limit course closure time.  The entire project (including corrective shaping) was completed in four weeks, during the annual closure for the over-seeding process.  

Due to limited funding the bermuda green, which was failing to perform to previous consultants beliefs and subsequently transformed to more poa than bermuda, was not touched.  In September of 2009, the green was double aerified and seeded with A4 bentgrass.  The slideshow below illustrates the establishment of bentgrass, which now populates the green in the 90-94% range.

  

The green is maintained in the same manner as the course greens in terms of mowing frequency and height of cut (currently .090")  To aid in the establishment of the bentgrass, the frequency of additional nitrogen applications is the only major alteration to our typical maintenance protocol.

 4/2007

6/2010

 9/2011

July 2011 Roots

Proper management of Bentgrass in Southern California can yield dense, deep roots.  These photos were taken today, July 21st, on the thirteenth green.  Bring on the heat....

(triplexed greens cut at .095")

Five Year Difference

Similar locations, several years apart:

 #6 green

 #6 green

 #2 green

#9 green

Defying the Odds

Three years and almost nine months later we are still managing 99.9% Bentgrass greens at Arrowhead Country Club in Southern California.  Industry speculators believe that this phenomenon cannot be accomplished and is not sustainable.  For Greenway and it's Superintendents, it is of no surprise.  In Southern California, where the seasonal time frame for poa annua establishment is long and pressure is high, most courses would be inundated with poa.  The sustainability is attributed to the correct management of Bentgrass from an agronomic and cultural standpoint.

Putting Green Shade versus Light

Many people have expressed interest as to why three Sycamore trees were removed from the surrounds of the practice putting greens.  An earlier post containing video narrates the primary reasons, but the pictures below say a thousand words.  The Sycamores close proximity to the putting surfaces allowed for root competition for water and nutrients, provided high volumes of shade (especially in the winter months with their southern locations), and funneled traffic to narrow corridors on an already undersized green.  Turfgrass requires high volumes of light to handle to the wear and tear of play.  The putting green sustains the highest volume of traffic of all greens on the course.  Combine lack of sunlight and high volumes of traffic and turfgrass decline is almost always the result.  As an example, when you are out on the putting green, look at the turfgrass quality on the northern side and then compare it to the southern side.  I am willing to bet that after inspection, even the untrained eye will note a difference.  

Be sure to note the improved density and quality of Bentgrass in the coming weeks now that the trees have been removed.     

Shade present prior to Sycamore removal

Light After Sycamore removal

Tree Decay within the Sycamore:  Future Danger

February Roots

A photograph illustrating the healthy, root depth on a portion of Hole #2 green.

Then and Now (2006 & 2010)

Photos from nearly identical locations on September 27th, 2006 and September 27th, 2010. Amazing how far we have come. Just further proof that the correct implementation of Marc Logan's philosophy on Bentgrass management can provide nearly unparalleled conditions in late September in Southern California.

Notes: 100% A4/T1 Bentgrass, cut with a triplex mower at .090", with 7+ inch roots after a week in the mid-100 F degree temperatures.

Soil Temperatures

As air temperatures reached 111.2 F yesterday at ACC, a soil thermometer shows the temperatures at two different depths within a green's soil profile. At 2 pm the air temperature was 109 F. The soil temperature at 1" down was 96.7 F. Within six inches of the initial probes location, the temperature registered five inches down was 88.7 F.

1" below green surface:

5" below green surface:

Bentgrass versus poa

The poa versus Bentgrass debate is always a contested one. Most say that you cannot grow Bentgrass in Southern California and that poa will out compete Bentgrass in the long run. "It is only a matter of time...." they say. We disagree.

For those of you that remember the tense summers at ACC in years past when the poa would struggle mightily or perish in the heat, I pose the question to you, "Which would you rather have, Bentgrass or poa?" Bentgrass can establish itself and be dominant in Southern California given that the correct management practices are being implemented.

One of the major benefits of Bentgrass is that it is more tolerant of abiotic (non-living) stresses on the extreme levels. I will focus on temperature for this post. The photos below illustrate the difference in root depth between a poa green and a Bentgrass green here in Southern California this summer. The poa root depth may be an inch. The Bentgrass, seven inches.

Root depth and mass are very critical to surviving the summer heat. When soil temperatures reach 80 degree Fahrenheit, new root growth ceases and the aging process begins. At above the mid 90 degree mark Fahrenheit, root hairs dye back and fail to function properly. When the air temperature exceeds 90 degrees fahrenheit, the soil temperature in the upper 1/2" can reach reach upwards of 100 degrees on a bright sunny day. When looking at the illustration below of the shallow poa roots, that can be deadly.

We have had a very mild summer to date and our soil temperatures remain in the upper 60's F in the early part of the morning. Those temperatures creep into the mid to upper 70's F in the afternoon.

Poa Green roots in July:

Bentgrass green roots in July:

Early Summer Roots