Building better greens

The phrase “built to U.S. Golf Association recommendations” connotes the confidence and quality one can rely on for a superior green and optimum playability – a green that exudes the craftsmanship of professionalism. To golf course superintendents, the phrase “built to USGA recommendations” means a green is built to the highest standard using the latest in scientific research about what materials constitute the highest quality green.

But with all the different construction products and techniques used, superintendents are faced with myriad choices when constructing greens. Faced with selecting products and methods that will work best for them and their courses, superintendents look to the USGA to provide clear guidance about constructing a USGA-quality green.

“When you’re writing guidelines being used as specifications, you can’t go with something you think works some of the time but you know doesn’t work some of the time,” says Jim Moore, director of construction education with the USGA. “You stick very strongly by what you’re sure works.”

In its ongoing efforts to assist superintendents to determine the best products for their courses, the USGA made its most significant changes to its recommendations for a method of putting green construction by broadening categories that define what and how materials can be used to construct greens. These changes, which were implemented in 1993 and 2004, were made to accommodate the fast-evolving technology in course materials and construction methods and to address issues relating to testing on certain construction materials and methods.

While reviewing the most recent recommendation changes in 2004, one can see the USGA’s goal to broaden the guidelines wherever possible by the emphasis it has placed on expanding the definitions of accepted materials and construction methods to build better greens more easily, more cost effectively, and using the latest in technology and materials. While acknowledging greens are different and one solution doesn’t fit all, the USGA seeks to eliminate the unknowns of green construction by testing new technologies and materials for quality and performance.

Recommendation revisions
Initially created in 1960, the USGA recommendations have been the industry standard as well as the most widely used method of green construction throughout the United States and internationally. Before amending the recommendations in 2004, they were revised in 1965, 1973, 1982, 1989 and 1993. These revisions were made to ensure the success and performance of greens that are constructed according to the recommendations, which the USGA constantly reviews to make certain the methods keep up with the many new challenges of green maintenance. Adding to these challenges is the evolving technology that improves the quality of the soil and reduces the cost to construct greens.

With its emphasis on research paramount, the USGA has funded more than $1 million of research on course constructions since the last recommendation changes in 1993. With a surge in the popularity of golf growing since the early 1990s requiring additional lab testing on products used in construction, the need for consistent guidelines has never been greater.

Broadening recommendations
Seeking to evolve with the technological changes and to address superintendents’ concerns on the undetermined performance of several new products on the market, the USGA made its first efforts to specifically broaden certain recommendations in 1993. These changes to include new construction methods and materials were intended to make the process of building greens easier and more cost effective and sought to provide greater flexibility in the construction of USGA greens. These changes were all made with the caveat that the greens had to be properly tested and approved for USGA-standard quality and consistency.

One of the most significant 1993 changes occurred when the USGA altered the dynamics in course construction to mirror what more builders and architects were successfully using and to make new course constructions more cost effective. The change was to include the option to omit the intermediate or choker layer. This was the biggest change the USGA had ever made to its guidelines, according to Moore.

“[The intermediate layer] is very difficult and expensive to put in, and, prior to 1993, the USGA insisted it be the greens,” Moore says. “There were a lot of greens being built without it, and some performed wonderfully. We would also see greens that failed due to the movement of the root-zone mixture down into the gravel – it essentially eliminated the gravel layer.

“We saw failures we saw successes,” Moore adds. “But now, when people choose to build greens to USGA guidelines, they have the option of including the layer or leaving it out, depending on the makeup of their construction materials. Prior to 1993, we would tell you that you did not have a USGA green if you didn’t have that layer in there.”

Recent changes
By 2003, enough empirical evidence and research had come forth to mandate the recommendations be changed again. With 18 possible revisions, the USGA organized and sent the revisions through more than 200 people, which included such interested parties as architects, agronomists, engineers and trade professionals, and several committees before determining six revisions were necessary to the recommendations. These revisions included simplifying saturated hydraulic conductivity, widening the tolerance of the root-zone depth, widening the specifications for gravel size, increasing the coefficient of uniformity for gravel, allowing for the use of flat pipe with certain specifications and allowing for the use of inorganic amendments in green construction, pending approval by the physical soil testing laboratory of the final root-zone mixture.

What works best?
The inclusion of inorganics to the 2004 recommendations is one example of the USGA’s efforts to broaden definitions in the materials used to construct a USGA-quality green while addressing concerns about the performance of products whose performance tests have been determined to be inconclusive.
Specifically excluded prior to 2004, porous inorganic amendments such as porous ceramics, calcined diatomites and zeolites were added to the recommendations. While the 2004 changes allow for the use of inorganics in the greens mix as long as the particle size and performance criteria of the mix were met, the recommendations also provide a cautionary note that users should be aware of the differences in products and that conclusive testing on the performance of the inorganics was not prevalent.

To be sure, some in the golf course construction industry believe a sand/peat root-zone mix is the best mix for green construction. However, field evidence of greens that have mixed in inorganics has shown to also work well. Such inconsistent experiences are the nature of much confusion from golf course superintendents on what the best product is for them to use and an issue the USGA sought to address with the 2004 change.

One might believe the insight of golf superintendents might have influence over the issue. However, even this insight might be insufficient. 

“By far, the greatest variable in how greens perform is the turfgrass manager,” Moore says. “It far outweighs the construction of the green. I’ve visited superintendents in some climates that seemed to be able to grow grass on concrete in full shade. I’ve visited others that have everything going for them, and they still have problems.”

Moore says climate, the method of how a green is constructed, the type of materials used in the construction and the varying managing ability of superintendents all have influences on how a green performs. Moore says adding an inorganic to the mix doesn’t necessarily conclude it will perform better.

“If we build a golf course in full sun, with full air movement, no traffic, it’s in Colorado where we don’t get any real disease pressure,” he says. “We build the green like the back of a turtle so we have great surface drainage – it’s practically a given that the green is going to perform well.”

Recent side-by-side test results have also provided additional insight and guidance to the options superintendents have today in constructing an agronomically sound root zone. In a recent Ohio State study, for example, the use of inorganic amendments was shown to significantly improve sand-based root zones’ nutrient retention and prevent soluble nutrients from leaching and polluting the environment. Such research has been invaluable when assisting superintendents to determine the best mix and techniques that will work best for them.

Of course, some superintendents will rely simply on tried-and-true experience to determine what materials and construction techniques will work best for them. Ed Seay, executive vice president and chief operating officer with Arnold Palmer Golf Courses, has been a proponent of using an inorganic, porous ceramic, in all Palmer courses. Seay says he recommends their use because they’ve provided superintendents with reliably positive results.

“Every spec we send out has Profile Porous Ceramic included,” Seay says. “The grass grows better and more consistent and it gives you a stable, solid root zone.”

Continuous improvement
Ideally, the best research for individual superintendents and their course’s performance will always be detailed studies conducted on each superintendent’s individual course. Given this implausibility, the USGA has spent years of research and millions of dollars to determine the performance of materials used in green construction across a wide – and more practical – range of uses and environments. Even with the broadening of the recommendations, many believe much research still needs to be done to accommodate new technologies, alternative materials and cultural practices to achieve the best courses possible. As such, the USGA continues to seek to provide golf course architects and superintendents clear guidance on the use of the wide variety of products and their expected performance to ensure that their greens are built to the utmost quality.

Sarah Willnerd is a writer with Swanson Russell Associates, a communications firm, in Lincoln, Neb.