Honda LPGA at Siam CC, Novotek, Seashore Paspalum, and the #STMIA15 Field Day

The 2015 Honda LPGA Thailand is underway at the Siam CC Old Course this week. Here's a look at the first round highlights.

The greens are Novotek bermudagrass, and the fairways are seashore paspalum. They look great. And the players are making lots of birdies and even eagles on these smooth greens.

At Siam CC, there are 3 courses on adjacent property. The Old Course, closest to Pattaya, down the valley to the Waterside Course, and up the other side of the valley to the 27 hole Plantation Course.

On March 10, the Waterside Course will host the Asian Turfgrass Field Day -- preview here. This is part of the Sustainable Turfgrass Management in Asia 2015 conference. Also, on March 12, conference delegates have the chance to play golf at either the Plantation (host venue for the 2015 Thailand Open) or the Waterside Course at a special conference delegate rate.

More about grasses on golf courses in Thailand: a Christmas Eve miscellany

Sunset_banyanGolf in Thailand at this time of year is really pleasant. I often use the words clement and salubrious, with additional modifiers, to express just how pleasant I find it.

Over the past 20 days in Bangkok, there has been no rain, and the temperature has ranged from 19 to 34°C.

I've written about the grasses one finds here, and I have also put together this photo gallery of the typical grasses. Most putting greens are hybrid bermudagrass, and after that comes manilagrass, and there are comparatively few courses with seashore paspalum greens.

Through the green, the percentage of courses with bermudagrass goes down, and the percentage with manilagrass and seashore paspalum comes up.

Turfgrass @ Thailand

At the Sustainable Turfgrass Management in Asia 2015 conference, we will be talking about these grasses, and we will have a pre-conference seminar in which we discuss the design and construction of golf courses in Southeast Asia.


It hasn't rained in Bangkok for 20 days, yet on the seashore paspalum fairways I played today, this was the result from multiple shots that landed in the fairway: debris (organic matter, or mud?) on the ball.

2014-12-24 13.50.15 2014-12-24 11.20.57 2014-12-24 11.38.52
I think the cause of this is related to the grass species. In Southeast Asia, when one does not keep the soil wet, seashore paspalum will eventually be overtaken by better-adapted species that thrive in drier soils. So seashore paspalum fairways must be kept really wet if the grass is to persist. One can topdress with large amounts of sand to minimize that problem, but that is really expensive.

A recent post on about seashore paspalum had some interesting comments from golf course superintendents and golfers and architects about this species. The consensus -- it requires a lot of inputs and can be very expensive to maintain.

I've got lots of ideas about grass selection and construction methods (especially sandcapping of fairways) and will be working on developing those for discussion at the upcoming conference. 

The importance of irrigation water testing

Brad Burgess wrote:

I would appreciate your thoughts and comments re this water test. I just read your PACE Turf Article and thought I would run this by you. It could be a nice study for you re salt tolerance in Zoysia …

Never seen water this bad before and tested it after the fact. 

Others have said this water is not even suitable for Paspalum … 

Look forward to your comments. Also attached some photos … at 90 days after planting.

This water had electrolytic conductivity (EC) of 1.4, pH of 9, calcium at 4.7 ppm, magnesium 3.7 ppm, and sodium 314 ppm.

I responded:

Thanks for the photos and the water test.

Photo of turf at the site being grown-in with this irrigation water.

The grass looks great. And that is a pretty poor water. It would be an interesting site to do some tests.

My thoughts on the water -- the 2 most important things to look at are total amount of salt (EC) and SAR [sodium adsorption ratio]. 

EC is what one looks at to see the effect salt in the water is going to have on the grass, how that may accumulate in the soil, and how much extra water will be required to keep the soil salts at a level the grass can tolerate.

For the salt content, it isn't too bad. The leaching requirement [for more about leaching requirement, and how to make these calculations, see this handout] for zoysia using that water, if I use a soil EC tolerance level of 8 ds/m, is 0.037, so the amount of extra water required is minimal, ET / (1 - 0.037). But if the soil structure would deteriorate, then one couldn't leach to maintain the soil EC at 8, and then the salt would damage the grass. As a comparison, the irrigation water at [golf course name redacted] has had 4 times as much salt as this water, and Tifeagle can still be maintained to a high level, as long as one leaches properly.

SAR is what one looks at to see how the sodium may cause a problem with soil structure.

I think [this lab’s water test is flawed] because it does not provide the SAR directly, forcing the customers to calculate it themselves, while emphasizing [less relevant data]. 

For this particular water, the SAR is about 26, which is especially bad for soil structure, especially because the water doesn't have a high salt content. One expects the regular use of this water to cause problems with soil structure (unless it is a sand rootzone) over time, exhibited by slowing of water infiltration. This problem can be addressed by regular applications of gypsum. The amount of gypsum to apply is based on the amount of sodium added in the water, or based on the ESP of the soil. Gypsum can be applied at pretty high rates, like 200 to 400 g/m2. I make a rough calculation that for every liter of water added, one should apply 1.5 g gypsum/m2 to prevent soil structure problems. So if 150 mm of water were added in a month, that would be a 225 g/m2/month gypsum requirement.

To summarize, I'd be concerned about soil structure with this water, would apply 1.5 g gypsum/m2 for each L of water that was applied, with that being done to prevent soil structural problems (disregard that advice on a sand rootzone), and I would make sure that slightly more water was applied than ET, to prevent salinity problems.

I’d like to emphasize three things.

1. It is really important to test the irrigation water. Because Brad had this water tested, he can identify and prevent potential problems. What is in the water is invisible. Many sites have water that is perfectly fine, and a test will confirm that. For locations with high salinity or high SAR, that problem is invisible in the water, until there are visible problems on the turf, and by then it is way too late.

Seashore paspalum has died at this site where salt has accumulated in the soil. This problem can be prevented by knowing what is in the water and then carefully managing the salinity through leaching.

2. Make sure the water is being tested for the right things. One needs an irrigation water suitability test. A comprehensive guide for this is Harivandi’s Interpreting Turfgrass Irrigation Water Test Results. In that, he writes:

When irrigation is applied to the soil, the best indicator of sodium effect is a water’s Sodium Adsorption Ratio (SAR), a value which should be provided in all laboratory water analyses. 

3. If for some reason SAR is not reported, one can calculate it from this equation:

\[SAR = \frac{Na}{\sqrt{\frac{Ca + Mg}{2}}}\]


SAR is sodium adsorption ratio

Na is the sodium concentration of the water in milliequivalents per liter

Ca is the calcium concentration of the water in milliequivalents per liter

Mg is the magnesium concentration of the water in milliequivalents per liter

Everyone knows zoysia grows slower than bermuda, except when ...

... it doesn't. In fact, there is one variety of manilagrass (Zoysia matrella) that consistently grows faster than bermudagrass in Southeast Asia. I've had occasion to study and measure this grass, and there is no doubt that it grows faster than bermuda here.

Manilagrass fairway on the Player Course at Orchard Golf and CC in the Philippines.

Some recent measurements have provided a bit more information. The grass I refer to is nuannoi, the manilagrass variety that is grown on nurseries in Thailand, that I've seen growing as far east as the Philippines, south to Singapore and Bali, and west to Dhaka. 

Many golf courses in Thailand were planted to bermudagrass when they were constructed in the 1990s and through a natural conversion process, the nuannoi has taken over. Courses such as Windmill, Green Valley, Thana City, and Phoenix Gold have all had this happen.

Banyan GC in Hua Hin, Thailand was planted to this grass at the time of construction.

I've measured how fast this grass spreads, both when it is invading bermudagrass, and when it is establishing on bare ground without competition from other grasses. Here are four separate measurements.

1. At the ATC research facility

Different species and varieties of warm-season grass at the ATC research facility in 2008.

More than 50 varieties of grass from various species were grown at the ATC research facility near Bangkok from 2006 until 2009. One of the interesting observations was just how quickly nuannoi manilagrass grew into Tifway 419 bermudagrass. Remember, people keep telling me that bermuda grows faster, and zoysia grows slower, but as you can see here, the invasion was only happening in one direction. Which grass is growing faster?

The yellow pen marks the farthest extent of manilagrass invasion into a plot of bermudagrass.

From the plot border, to the farthest point of invasion, was 2 meters at this point, and the grass had been planted for 2 years. This is a rate of 1 meter per year, or 8 cm per month.

2. In Samui

The Santiburi Samui CC opened at the end of 2003. It was planted to seashore paspalum, except for the Tifeagle greens.

The 2nd shot at Santiburi Samui in January 2004, when the fairways were still seashore paspalum.

Most of the seashore paspalum on the fairways and roughs died during a drought in 2005. Where the paspalum died, bermudagrass took its place. I first noticed a few small patch of nuannoi on fairways at Santiburi Samui in January 2007. Since then, the nuannoi has continued to expand into the bermuda, with the largest patches now having an area of about 140 m2.

Large patches of nuannoi on the Santiburi Samui fairways in May 2014.

Assuming that the size was one small plant in January 2007, and the patch of manilagrass is now 140 m2 in size, gives an expansion rate of 7 cm per month. 

Based on the measurements at the ATC research facility and at Samui, the rate of expansion into established bermudagrass was 7 and 8 cm per month, respectively. This expansion rate is useful for doing planned fairway conversions, both to know how long it will take for the nuannoi to take over, and to calculate an appropriate spacing for planting.

3. In a greenhouse experiment

I've shared some results from a greenhouse experiment conducted last year in Thailand, in which nuannoi manilagrass, Tifway 419 bermudagrass, and Salam seashore paspalum were established from stolons in a sand rootzone and the growth and the nutrient uptake were measured. After the grass was already grown in, during the duration of the fertilizer and clipping yield experiment, the nuannoi manilagrass had 52% more clipping yield than did the Tifway 419 bermudagrass.

But before that, it grew in faster from stolons also.

42 days
Nuannoi manilagrass 42 days after planting by placing 5 stolons in the pot.
Nuannoi manilagrass 48 days after planting by 5 stolons in each pot.

The manilagrass had grown in after 42 days (6 weeks). The planting rate of the stolons was 144 g/m2

4. At a sod farm

I've explained the process of manilagrass production on sod farms near Bangkok in this video, where the grass goes from planting to harvest in about 6 weeks.

Measuring surface hardness on greens, fairways, and approaches

I measured soil moisture and surface hardness on three fairways, approaches, and greens at a golf course in Thailand last month. The fairways and approaches at this site are seashore paspalum on a sandcap. The greens are ultradwarf bermudagrass on a USGA green.

For some background info with data and charts from previous measurements, see this.

I do this to study a few things:

  • what type of soil moisture levels are normal
  • what type of surface hardness levels are normal
  • what is the relationship between construction method and surface performance
  • what is the relationship between grass species and surface performance
  • how the surface conditions change over time 
  • how the surface conditions change with different maintenance inputs

I used a TDR-300 to measure the volumetric water content of the soil to a 7.5 cm depth. At that same location, I used a Clegg Golf Course Tester with a 500 g hammer to measure the surface hardness.

The surface hardness decreases as soil moisture increases from greens (g) to approaches (a) and fairways (f).

For playability, I would prefer the fairways to be harder. I'm not an advocate for sandcapping of fairways in Southeast Asia. Even though the fairways at this location are sandcapped, the surface is soft. With these data, the golf course superintendent can make some changes to the fairway management and perhaps the surface hardness can be increased.

I also used the TruFirm to measure firmess at the same location. There is a bit more variability with the TruFirm, compared to the Clegg, but the result is the same – the greens are firmer, and the approaches and fairways are less firm. Note that a lower reading by the Clegg means softer, but a lower reading on the TruFirm means firmer.

The surface firmness (lower values are firmer) goes away as soil moisture increases from greens (g) to approaches (a) and fairways (f).

Turfgrass ecology, part 2: abandoned turf in Thailand

In the southern Tohoku region of Japan, ceasing maintenance of creeping bentgrass leads to grass death and almost complete invasion by weeds. Manilagrass (Zoysia matrella) stays alive for at least 18 months with no maintenance, and has minimal weed invasion. Japanese lawngrass (Zoysia japonica) also stays alive, but has more weed invasion than seen on manilagrass.

What happens with manilagrass and other grasses like seashore paspalum (Paspalum vaginatum) and hybrid bermudagrass (Cynodon dactylon x C. transvaalensis) when maintenance is stopped in the tropical conditions of Thailand? And do observations of what happens when there is no maintenance have some implication on what the maintenance requirements may be for those grasses? 

The Asian Turfgrass Center research facility north of Bangkok in 2008. The grass was maintained at this facility from 2006 until April 2009.

At the TT Tour in January 2008, we studied various grasses at the research facility. The grass immediately surrounding the paved area is manilagrass, and adjacent to the sala with the red tile roof is centipedegrass (Eremochloa ophiuroides).

Manilagrass at the edge of the potted grass nursery at the ATC research facility in January 2008.

In April 2009, irrigation was stopped at the research facility, and mowing was stopped from October 2009. So what happened to this manilagrass by November 2010, 19 months after the last irrigation, and 13 months after the last mowing? This is in Thailand, where the temperature is always warm, and the grass (and weeds) have the potential to grow all 12 months of the year. 

The next photo shows the same area as the previous photo, but at a different angle; the paved area is now at left (and covered by weeds); the manilagrass that people are standing on in the above photo is in the center of the photo below.

Manilagrass remains alive and free of weeds after 19 months with no irrigation and 13 months of no mowing. The centipidedegrass beside the sala has been overrun by weeds in the same time.

 How about bermudagrass and seashore paspalum?

Mowing was continued, but irrigation had been withheld for 5 months. Seashore paspalum is in the foreground, and bermudagrass is in the background.

The rainy season in this part of Thailand goes from late May until the end of October. The photo above was taken in mid-September 2009. Irrigation was stopped in April. Even though the grass was growing through the rainy season, the seashore paspalum in the foreground has almost all died without supplemental irrigation in only 5 months. The bermudagrass in the background remains alive, as does the surrounding manilagrass.

This next photo is taken from the same plot of mostly dead seashore paspalum, but turned to a different angle to show manilagrass in the background. The manilagrass, of course, remains alive with the natural rainfall and no supplemental irrigation.

After 5 months without supplemental irrigation, the seashore paspalum in the foreground is almost all dead. The manilagrass in the background remains alive.

Those photos showed the seashore paspalum after 5 months without irrigation. What happens after 19 months of no irrigation and 13 months with no mowing? In that case, the seashore paspalum has all died.

The plot of seashore paspalum 19 months after maintenance was stopped. It has now all disappeared and some weeds and other grasses are invading.

Seeing what happens when maintenance is withheld gives some indication of how much maintenance (irrigation, fertilizer, pesticides, mowing) are required when a species actually is maintained. Under the conditions of central Thailand, one can make some general observations based on this comparison of unmaintained grasses.

  • manilagrass seems to require only mowing to persist as a turfgrass and is the most resistant to weed invasion
  • seashore paspalum dies without supplemental irrigation
  • bermudagrass does not die without supplemental irrigation but will eventually be invaded by weeds if not maintained intensively

These observations of manilagrass are very similar to what was seen in the photos from Japan. Also, these observations of dying seashore paspalum are similar to what was seen in a controlled experiment in southern China. Xie et al. found that seashore paspalum turf under low maintenance was naturally replaced by manilagrass within 2 to 3 years.

Putting green construction and topdressing sand

Figure 1. A putting green being built using the USGA Recommendations for a Method of Putting Green Construction at Krabi, Thailand (January 2006)

When I teach about turfgrass maintenance, much of the discussion involves putting greens or other highly trafficked turf areas, because that is where most of the shots are played. And I am invariably asked questions about the type of sand to use, whether river sand can be used, or what type of amendments should be mixed with sand, and so on.

 These are important questions, and I have six things that I usually talk about when these questions are raised.

 1. Sand is a terrible medium for plant growth because sand has a low water holding capacity and low nutrient content. Plants, including turfgrasses, will generally grow better in soils containing some silt and clay than they will in sand. Of course, with regular maintenance, turfgrass managers are able to produce excellent turf in sand rootzones through the provision of water and nutrients to meet the plant requirements.

 2. However, a sand can be chosen that has two especially useful characteristics for high traffic turf areas. With the right particle size distribution, sands can be used that have a) a rapid infiltration rate, so that the surface is usable soon after a heavy rain, and b) resistance to compaction, even though there is a lot of traffic on the area. Infiltration rate and resistance to compaction — those are the reasons sands are used for high traffic areas.

 3. There are very specific recommendations for putting green construction provided by the USGA. This document, USGA Recommendations for a Method of Putting Green Construction, is freely available ( These are sometimes called the “USGA specifications” and they outline everything from the depth of sand to the type of drainage to the sand particle size and various physical properties that the sand must have if the green is to meet the specifications set out in the USGA Recommendations document. Make variations from these Recommendations, and the green may still perform well, but please don’t call it a “USGA” green if the Recommendations are not followed.

 4. For topdressing sands, a good starting point is to look for sands that have physical properties that meet USGA Recommendations.

Figure 2. The same green, 8 years later, still performing well, which is what one expects when a green is built following the USGA Recommendations (May 2014)

 5. I don’t think the Method outlined in the USGA Recommendations is necessarily the best way to build a green, but it is one that works, and it is a way to build a green that many people understand and know how to manage. Figure 1 shows the construction of a USGA green in Krabi, Thailand in 2006, and Figure 2 shows the same green still performing well in 2014. That type of predictable result is what we expect when building a green to USGA Recommendations.

 6. If I were building a putting green for myself, and if I knew that I would be the one to manage it, I would probably build a green with some soil in it, with lots of surface drainage, with a slower infiltration rate than in the USGA Recommendations. But if I were building a green for someone else, and I knew that I would not be responsible for maintaining it, I would choose the USGA Recommendations. That way, the risk of unexpected problems is much reduced. 

 I encourage everyone to download a copy of the USGA Recommendations and to be familiar with the document. Many problems and confusions could be avoided by a broader understanding of this Method.

 I wrote this as part of a series for the Indian Golf Industry Association (IGIA) newsletter. For more about turfgrass information specific to India, see the ATC site

3 fine football fields

On the eve of the World Cup, I have three quick things to share about football/soccer. 

Kashima Soccer Stadium, March 2014

1. I've been to two matches at the Kashima Soccer Stadium (this was a venue for World Cup games in 2002) in the past year, one at the end of summer, and one at the beginning of spring. The grass is a mixture of 2 kentucky bluegrass (Poa pratensis) varieties and one hybrid bluegrass variety. In this part of Japan it would be typical to use warm-season grasses on sports fields – summer temperatures are similar to those in Atlanta – and on the surrounding golf courses and lawns, warm season grasses are grown. I've been impressed at just how good the turf is here. Almost all the stadiums in J.1 are bermudagrass, so this pitch at Kashima Stadium is exceptional in being cool-season grass, and exceptional in being maintained to such a high standard. 

2. In the Thai Premier League, one can find matches played on bermudagrass, zoysiagrass, and seashore paspalum. Muangthong United play at the SCG Stadium on the north side of Bangkok, and the pitch here is seashore paspalum.

Seashore paspalum at SCG Stadium in Bangkok, April 2014

To keep the ball moving quickly, water is added at halftime. 

Irrigation at halftime, SCG Stadium

This is the best pitch I've seen in Thailand.

3. If you haven't watched this feel-good story about the amazing Panyee FC in an amazing part of Thailand, take a couple minutes and watch it now. I bet you haven't seen football played like this.

The grass that doesn't die ...


is the one that gives the turfgrass manager the most options in the surface that will be produced, and is the one that is most sustainable. In this new podcast on the GCI Superintendent Radio Network, I talked about "The Survivors" with Kyle Brown.

Listen to the podcast, read the article I mentioned about grass selection, or listen to my previous discussion with Kyle: "Control the K."

Of trees, turf, and tropical tournament golf

The Asian Tour is at the East Course of Wack Wack Golf and Country Club this week for the Philippine Open. This photo from pro Yoshinobu Tsukada is the par 3 8th, one of the classic short holes in Asia. One notices a lot of trees, with just a narrow corridor for play.

In a tropical climate, trees and shade can be a desirable feature on the golf course. Shade is certainly welcome, at least from the players' point of view.

Caddies and golfers at Bangsai CC north of Bangkok use umbrellas to provide shade on a sunny summer day

Not all grasses can handle the shade from clouds, combined with the shade from trees. At Wack Wack's East Course, there is manilagrass on the greens, and tropical carpetgrass on fairways and rough. These grasses, tropical carpetgrass (Axonopus compressus) and manilagrass (Zoysia matrella), are the two species that can tolerate low mowing (less than 5 mm) under appreciable tree shade in a tropical climate.

If one wants to have grass, and have trees, then these are the grasses that work. And they require minimal inputs, can be mown as short as one likes, and they can be maintained to the highest level for international tournaments.

These species also work on the local courses that want to have good playing conditions, but may not have an irrigation system, or a big budget. 

The 1st at Khet Udom Sak GC in Chumporn, Thailand: manilagrass greens, carpetgrass through the green, no fairway irrigation

 And when it rains, these species can handle the tropical rains just fine. But most importantly, they are the species that tolerate low mowing in tree shade in a tropical environment. For more info, see the links immediately below this post.

The 7th at Pakasai CC in Krabi, Thailand: manilagrass greens (3.5 mm), carpetgrass through the green (8 mm on surrounds)