The Best Grass for Golf Putting Greens
While many opinions about the cool season and warm season grasses for use on golf putting greens may be found, there is little doubt that the majority of golfers world-wide would prefer to putt on bent grass greens. Bent grass (classified as a cool season species) certainly is the Cadillac of putting green grasses and makes for the smoothest, truest and firmest surfaces. This is especially true with the many new and emerging modern cultivars that have been developed in the last several decades.
It is for these above reasons that most of my previous writings on golf putting green management has focused a good deal on managing bent grass greens. However, there are circumstances and climatic regions where the shear practically of using creeping bent grass becomes formidable.
Grasses are distinguished genetically into two large groups:
- Cool Season
- Warm Season
The growth characteristics of these two groups are obvious from the nomenclature, but the groups coincide into two distinct types of photosynthesis as to their processing of carbon (C). This processing of carbon via photosynthesis light reactions is referred to as the Calvin Cycle as related to carbon dioxide utilization. Without going into a detailed chemistry lesson, cool season grasses are classified as C3 type photosynthesis and have limitations on how much light they can utilize, whereas warm season grasses are classified as C4 type photosynthesis and can utilize light intensity to a linear degree.
Most usually due to the extremes of constant high temperatures, higher humidity / rainfall as well as high intensities and duration of light often encountered in dessert, tropical and equatorial regions, species other than bent grass are often employed for golf putting greens. There are a number of species of warm season, C4 warm season grasses that have been developed for golf putting greens to include cultivars or hybrids of Bermuda grass, Zoysia and Paspalum.
While a few other warm season species are found in use on golf greens around the world, these three species predominate in warm season usage.
The Equatorial Tropics
The equatorial regions of the tropics are increasingly important to the future of the game of golf. Currently about forty percent (40%) of the world’s population lives in these regions and it is estimated that this percentage will increase to around sixty percent (60%) in the next fifty (50) years. Obviously the population shift will also bring changes in golf course management as more golf courses are developed in the tropics. And, of course, hotter climes are not limited to the torrid zones of the equator.
Warm Season Grasses–Management
Generally the development of what I have previously termed the 4Ps of golf greens management evolved toward perfecting consistent creeping bent grass golf greens. Being a seasonal cool season species, bents have a different annual cycle of growth than do the warm season species that are used on greens. However, utilizing the 4Ps on warm season grasses is also highly effective with thoughtful consideration of the seasonal cycle and needs of these species.
The management of warm season grasses on greens should also be systematized into the 4Ps of:
- Rootzone Management
- Surface Management
- Nutrient Management
- Water Management
Furthermore, warm season grass species especially respond best when all cultural practices are employed in light, frequent application methods and regimes, just as with cool season bent.
While there are numerous genus and species of warm season grasses used for turf purposes, primarily hybrid Bermuda grass, Zoysia and Paspalum are commonly used for golf putting surfaces.
Paspalum is used on some of the best golf courses in Southwest Florida including, Crown Colony Golf And Country Club in Fort Myers and The Quarry Golf Club in Naples.
Seashore Paspalum (Paspalum vaginatum) began to find its way onto golf courses in the 1970s and early 1980s. Driven by the need to find new grasses that could tolerate high salt content water along with the stresses of heat and humidity, golf course superintendents, turfgrass researchers and commercial grass suppliers turned to Paspalum as a real solution.
Paspalum is a tropical grass originally found in North and South Americas’ warm coastal regions. As a perennial it spreads rapidly by both stolons and rhizomes. Its greatest attribute is that it has a very high tolerance to saline soils and brackish water once established.
Interest has rapidly developed in Paspalum since the 1980s and solid progress has been made to research its physiology and management. One highly promising cultivar that is now commercially available from Phillip Jennings Turf Farms is called ‘SeaDwarf’ Seashore Paspalum. SeaDwarf promises to become a very viable golf putting green grass – and even more.
SeaDwarf is a true dwarf cultivar of Seashore Paspalum that exhibits a super-fine texture, high tolerance to salts and demands low inputs of irrigation and fertility. Like all Paspalums, it must be carefully nurtured to an established maturity and then a low-input maintenance regime can be implemented. It must be noted that over irrigation is a nemesis to Papalums and this requires a changing of attitudes by managers.
To learn the latest practices and gain success in managing Seashore Paspalum, I highly recommend an excellent book by Dr. R. R. Duncan and Dr. Bob Carrow entitled, “Seashore Paspalum: The Environmental Turfgrass.” This book is a must for anyone who intends to seriously consider growing Paspalum.
Keep a close watch on the Paspalum species over the next several years as interest in the market place is heating up and breeders are now focusing on developing improved cultivars–much to the relief of many golf course superintendents around the world.
Overseeding and Transition
In the transition zones between the tropics and the temperate regions, the use of warm season grasses can provide for excellent putting surfaces during the hot and humid seasons. Then using cool season grasses to overseed can extend the green color for a longer golfing season.
Zoysia does not lend itself well to a cycle of overseeding for winter color. The problem is the slow transition in the spring. A skilled superintendent can overcome this problem with careful applications of contact herbicides that will remove the cool season grasses before the Zoysia begins to green up in spring. However, this must be done with much technical understanding and careful chemical application in order to avoid damaging the Zoysia.
By far, the hybrid Bermuda grasses do the very best with a cycle of cool season overseeding. In the desert regions of the United States and in Florida, overseeding of Bermuda has been developed into a reliable and precise management practice. A trip to Palm Springs in February will provide good proof of this fact.
By far the most tenacious disease problems on warm season greens most usually involve the numerous ‘patch’ diseases that attack the roots and crown of the plants. These diseases (typically ectotrophic root diseases) are most often exacerbated by more management practices related to fertility and the buildup of thatch. Usually the real damage is done to the plant’s root system in the late fall as dormancy is entered. Then in the spring the damage earlier done in fall becomes obvious as the spring dead grass shows up.
In sum, properly follow the 4Ps of golf green management and you will avoid most all disease problems with warm season grasses on golf greens.
As with all grasses used on golf course putting greens, the key to success or failure is simply management! One big concern of many of us in the golf course business is that poor management will lead to failure of some great, emerging cultivars in all species. It is important that when deciding to use the new grasses on golf greens, the golf course must be totally committed to the proper education of its management and the training of its staff on how to best manage these grasses. While it is not ‘brain surgery,’ it is still science and technical management. These require the ‘brain maintenance’ of the management team. Classes, seminars and turf conferences are a necessary investment along with the investment in the new grasses.
Don’t allow poor management to give the new, emerging, warm season cultivars a black eye! Make sure your golf course management staff is as up to speed as these new, great grasses are.