This chart shows a selction of world cities, plotted by average temperature, sunshine, and precipitation for the month of January. Bangkok, Chennai, Colombo, and Mumbai look like splendid places this month, at least for the growth of warm-season grasses. It will normally be warm, sunny, and dry in these cities, allowing turfgrass managers to control the growth with fertilizer and water applications, without concern for a lack of sunshine.
On these charts, a selection of world cities are plotted according to their average annual temperature and average annual sunshine hours, with the size of the bubble for each city proportional to the average annual precipitation. The display of information in this way allows us to identify quickly some differences between the normal climate in different locations. Miami and Honololu, for instance, are very similar in average annual temperature, and almost the same in sunshine, but Miami has much more rainfall than Honolulu.
The charts are shown with the x and y axes going to zero in the plot above, to get some sense of the range of variation in the data, and in the chart below the data are plotted to fit the chart, so that we can more easily identify the location of the cities. Atlanta has a similar annual temperature to Osaka, and similar precipitation, but there are about 40% more sunshine hours in Atlanta each year than in Osaka. That difference is clearly something to consider if we think about how, for example, ultradwarf bermudagrass greens would perform, or should be managed, in those different locations.
Photosynthesis is affected by temperature, light, water availability, and leaf nitrogen content. Turfgrass managers control the nitrogen by judicious application of fertilizer, and the water availability is controlled partly through precipitation and partly through supplemental irrigation. Light and temperature, then, stand out as the uncontrollable influences on photosynthesis. In the warm-season areas of the United States, there tends to be relatively high sunshine. It is normal to have 2500, 3000, or even 3500 sunshine hours in a year. So in the United States, much of the grass selection, when it comes to warm-season (C4) grasses, is just a matter of temperature -- "is this a warm-season area, by temperature, or not?"
In Asia, there tends to be less sunshine. If we compare Hong Kong with Miami, we see that Miami is slightly warmer, and Hong Kong has a bit more precipitation, but there is a huge difference in sunshine hours, with Miami having on average about 70% more sunshine hours than at Hong Kong. Does this have an affect on turfgrass performance? Yes! We see Zoysia matrella thriving in Hong Kong, and Singapore, and Tokyo, all cities where the sunshine hours are relatively low. Bermudagrass, on the other hand, performs relatively poorly in these same cities, and requires special care to keep in a playable condition.
This chart shows a selection of world cities, plotted by their average temperature, precipitation, and sunshine hours for the month of October. An interactive and customizable chart with the climatological data is here.
In October, the temperatures in much of East Asia are at an optimum for cool-season grass growth. Shanghai, Osaka, and Tokyo finally see their average temperature move less than that of San Diego after a long summer. The Japan Open is held in the middle of October every year, an ideal time considering the weather and the typical playing of the event on a course with creeping bentgrass greens.
In South and Southeast Asia, we can again see that there is more precipitation and less sunlight than in American cities with similar temperatures. October and November mark the end of the rainy season at places such as Bangkok and Kolkata, moving into the drier and sunnier months of the northern hemisphere winter.
This chart shows a selection of world cities, plotted by their average temperature, precipitation, and sunshine hours for the month of September. During September, many Asian cities are clustered at the bottom right of this chart, indicating a relatively warm temperature and relatively low sunshine hours.
For many cities in Southeast Asia, this is the beginning of the end of the rainy season. Day lengths near the equator are relatively constant throughout the year, but in places such as Guam, Kota Kinabalu, Bangkok, and Chennai, it is the upcoming winter months that have the most sunlight hours. We will see Bangkok, for example, move from being near the bottom of the chart in sunshine hours in September, to near the top of the chart in sunshine hours by December.
If you've flown into Narita Airport in Chiba prefecture near Tokyo, and have happened to look out the window, you may have been surprised when you flew over golf course after golf course as the plane descended. Chiba prefecture has more than 150 golf courses, placing it third among Japanese prefectures in golf course count. Only massive Hokkaido in the north, and Hyogo prefecture near Osaka, have more courses.
This map shows a portion of Chiba prefecture where there is an especially high concentration of golf courses. The satellite image was taken in the winter, so we see that the korai (Zoysia matrella) fairways and noshiba (Zoysia japonica) roughs are dormant.
Many of the golf courses at Chiba were constructed in the golf course building boom of the early 1990's, and for these courses, there is a pesticide ban. I was a superintendent in 2000 and 2001 at Habu CC, which opened in 1996 and was thus subject to the pesticide ban. Here the inspection team from the prefectural government made a visit to inspect the course, the maintenance building, and our records. We could use wetting agents, Polyoxin-D, and phosphites; other than that there was very little in the way of chemical control products that we could use.
One thing that I focused on, with the limited resources we had to maintain the course, was to have the central playing corridors in as good a condition as possible. We tried to have perfect greens, tees and fairways as good as they could be, and less attention was paid to the roughs, particularly in out-of-play areas. You can see here, in a view from behind the 14th hole at Habu CC, that there are some weeds growing behind the green on this par 5.
I've sometimes had long discussions with Japanese greenkeepers about the philosphy of balance in golf course maintenance. If resources for maintenance are limiting, I've always strived to make green perfect and the playing corridors as good as possible. In Japan, there has historically been the idea that there should be balance on a course, and that all of the areas should be maintained.
Balance is alright if you have enough resources to maintain every square meter at a high level, but if those resources are not there, then striving for balance is a sure way to have mediocre conditions all over the course. I think every course has the resources to make their greens perfect, and I am fine to let some out-of-play areas be a little less-maintained if I can ensure the greens will be excellent. This is still a challenge in Japan, because many courses were built in mountainous areas in a bubble economy and are inherently expensive to maintain. Maintenance budgets then get cut again and again, and it is very difficult to maintain these courses with the desired balance. I was lucky in my work, to be a foreigner, and to have an American boss. In this situation it was easier, culturally, to focus our maintenance efforts on the playing corridors.
This bubble chart shows 46 world cities plotted by average temperature, sunshine, and precipitation in August. We see the continuing trend for cities in Asia to have more rain and less sunshine than cities where similar grasses are grown in the Americas or Europe. Bangalore, Bangkok, Mumbai, and Kolkata all have relatively low sunlight during this month. And transition zone cities like Shanghai, Osaka, and Tokyo are mixed right in with the tropical locations of Singapore, Colombo, and Sanya, but the transition zone cities are managing creeping bentgrass, for the most part, on putting greens.
Hong Kong averages 189 hours of sunshine in August. Compared with other cities plotted on this chart, that is rather average, in fact even a low amount of sun. But for Hong Kong, this is one of the sunniest months of the year. Only July, with 214 sunshine hours on average, and October, with 192 hours, will have more. With these charts we see that the consistently low sunlight hours in many parts of Asia means that although there is similarity in temperature throughout the year with other warm-season areas, the actual growing environment is completely different — there is no overlap in the combination of temperature and sunshine in any month of the year.
See below, in the motion chart showing these data over the course of twelve months. We plot the track of Hong Kong and Miami through one year and they describe/explore completely different zones of temperature-sunshine combinations. We can use some of the same grasses in these areas, but the management practices need to be adjusted to fit the local environment.
You are probably aware of The R&A's "Working for Golf" campaign and their active support for golf development around the world. Maybe you've been to the R&A-supported Sustainable Turfgrass Management in Asia conferences, held over the past few years at Thailand, Philippines, and Malaysia. The R&A's Golf Course committee have just this month unveiled a new web site, appropriately titled The Golf Course, that will be of interest to anyone involved in golf course management and development.
What do you find on the site? Relevant content, updated regularly, in the categories of playing performance, golfer expectations, turf management, economic performance, environmental stewardship, water resources, social responsibility, energy efficiency — the list goes on, all good topics.
Has anyone asked you about the fairy rings visible on the greens at Royal St. Georges during the Open Championship? I've been asked many times, and the best explanation I've seen is this article on The Golf Course site: "Provided the greens are mown frequently, as they are during The Open Championship, the growth stimulated by the extra nitrogen ‘fertiliser’ does not affect the smoothness of the putting surface and, therefore, has no adverse impact on play." The article goes on to explain how a team from the Sports Turf Research Institute conducted daily soil moisture measurements and other tests to assess playing surface performance, and it notes that "The R&A is far more concerned about the quality of how a surface plays than its aesthetics."
I've worked with Banyan GC in Thailand (pictured above) to prepare a case study about the use of drought tolerant (among many other beneficial attributes) zoysiagrass, and with Wack Wack Golf and CC in the Philippines (pictured below) to develop a case study on innovative renovation techniques and the use of native grasses. Wack Wack just hosted the Philippine Open on its shade-tolerant carpetgrass and zoysiagrass surfaces. Both case studies are now featured on The Golf Course.
Banyan GC case study (Thailand)
Wack Wack Golf and CC case study (Philippines)
Why is it so important to choose the right grasses, and why are these courses so notable for choosing the carpetgrass and zoysiagrass, native grasses that perform especially well in Asia? Have a look at the chart below.
We can choose Miami as a typical city for North American warm-season areas, and Kuala Lumpur as a city with typical conditions for Southeast Asia. You can duplicate this chart by going to the animated bubble chart and selecting just Miami and Kuala Lumpur, deselecting the other cities, and ensuring "trails" are on, and then clicking the "play" button. On the horizontal axis we have the average temperature, and on the vertical axis we have the average sunshine hours per month. These "trails" trace the temperature-sunshine combination throughout the year for each of these cities. One thing really stands out to me — these cities never overlap. There is not a month in the year, on average, when the temperature-sunlight combination at Kuala Lumpur is within the range of combinations seen at Miami. And vice versa.
On average, there is always less sunshine at Kuala Lumpur than there is at Miami. And the temperature almost never changes at Kuala Lumpur, while there is quite a bit of change at Miami. Even when it is the same temperature at Miami and Kuala Lumpur, there will be, on average, considerably less sunshine at Kuala Lumpur: just 50% to 75% of the sunshine hours we would have at Miami. These are, in short, completely different growing environments.
And I would argue, and the success at Banyan GC and Wack Wack Golf and CC and other clubs throughout the region would support this, that the native grasses produce superb surfaces, are tolerant of low light from the massive tropical trees and the cloudy weather so typical of Asia, and that native grasses outperform imported hybrid bermudagrasses and seashore paspalum in many situations.
This bubble chart shows 46 world cities plotted by average July temperature, July sunshine, and July precipitation. The plot for June had 45 cities; at the suggestion of Dr. Larry Stowell from PACE Turf, I have added San Diego to the chart for this and future months.
Hong Kong has a bit more sunshine in July, more than 200 hours on average; that is twice the sunshine that Kolkata or rainy Mumbai would have during an average July; Miami, Honolulu, and San Diego are salubrious in July with an average of more than 300 hours of sunshine during the month. The bubbles for Osaka and Singapore overlap in July. This is the first full month of summer at Osaka, and in that area the standard grasses on golf courses are creeping bentgrass on greens, Zoysia matrella in fairways, and Zoysia japonica on roughs. Osaka is overlapping with a tropical region and the summer is just beginning, showing how difficult it is to manage cool-season grasses in transition zone climates.
This bubble chart shows 45 world cities plotted by average June temperature, June sunshine, and June precipitation. The plot for May had 46 cities; because Kota Kinabalu and Brunei have similar weather conditions and often overlap on these plots, I have elected to omit Brunei for clarity.
Compared with May, the cities in India have more rain and less sunlight as some monsoons begin, and New Delhi is really hot, hotter than Dubai, Phoenix, and Las Vegas! Hong Kong still doesn't have much sunlight but there is more than in May. And there is a big difference in transition zone cities such as Shanghai, Tokyo, Osaka, and Atlanta; by temperature and rainfall these cities are similar but during the month of June there is a lot more sunlight in Atlanta. We can also see why it is difficult to grow bentgrass in Atlanta. The temperature in June is similar to Hawaii or Florida but the summer is just getting started.
