The Secrets of a Successful Turf Reduction Program

Key Takeaways

• Many golf courses irrigate more acreage than necessary, even in regions where water conservation is a priority.
  
  
• Replacing irrigated turf with plantings or landscape treatments that require little or no irrigation is a highly effective way to save water and potentially other resources.
  
  
• Carefully selecting areas for turf removal is a key to success. This work is ideally done in coordination with a golf course architect.
  
  
• Facilities must have a well-designed plan for how to kill and/or remove the existing turf.
  
  
• Plant selection, establishment timing and weed management are all important considerations. Weeds will be a challenge in the first several years and will require varying degrees of ongoing management depending on expectations.
  
  
• The goals and expectations of a turf reduction program should be transparent and clearly explained to golfers, course decision-makers and surrounding neighbors.
   

Why consider turf reduction?

Golf courses that maintain vast expanses of manicured turfgrass utilize more water and spend more on fuel, fertilizers and plant protectants than courses with less irrigated acreage. Acres of irrigated turf can appear as an enormous green space with little definition and texture. Imagine courses like Pine Valley, The National Golf Links of America, Cypress Point or Pinehurst No. 2 without naturalized areas. Prior to 2011, Pinehurst No. 2 was a sea of bermudagrass, but now it features acres of non-irrigated native areas that reflect the original aesthetic and design intent and have helped the course reduce water use by approximately 50%.

Removing irrigated turf is a trend that has been happening for decades as courses try to save resources, increase habitat value, and accomplish aesthetic and strategic goals. If done correctly, the result is a more-sustainable facility that requires less water and inputs. Moreover, the turf reduction areas can add visual interest to the golf course by parting the grass sea. Courses in dry regions typically consider turf reduction primarily for water savings, while courses that receive more rainfall often consider reducing irrigated acreage for aesthetic and economic reasons.
 

Where should turf reduction be targeted and how much should be removed?

Hiring a golf course architect to guide decisions on where to remove turf is a great place to start. This part of the process can be controversial and even contentious among golfers and homeowners. In general, people resist change, especially if they think it will impact their home value or golf experience. But turf removal can mean real progress for the long-term agronomic and economic health of the course and perhaps the surrounding neighborhood. There have been many successful turf reduction projects on golf courses across the country and there has not been a reported case where property values fell as a result. In some cases, the alternative to turf reduction is to shutter the golf course, which absolutely will impact real estate values and cause a significant uproar.

The “low-hanging fruit” for turf removal target areas are clearly on the outskirts of the course, on the opposite side of a cart path from the golf hole and in turf areas around teeing grounds. Several things to consider when locating turf removal areas include:

• Look into removing turf adjacent to homesites if any are present on the margins of the course. This helps to eliminate irrigation overspray onto homeowner fences, walls and other structures. This may also encourage golfers to aim farther away from the homes.
  
  
• Use the existing irrigation layout to guide turf removal decisions. For example, when removing turf along the perimeter of a hole, set the new turf line to correspond with sprinkler locations so they can be adjusted to avoid throwing into the turf-reduction area while still covering the irrigated turf.
  
  
• Sometimes it won’t be possible to match turf reduction areas with the existing sprinkler layout and irrigation changes will need to be made to accommodate the new turf lines. This will add extra expense to the project.
  
  
• In many cases, there are 10-20 acres of irrigated turf that can be removed around teeing grounds. However, courses should be mindful about removing turf between the forward tee and the fairway. Players with slower swing speeds should either have maintained turf immediately in front of their tee or have only a very short carry to reach turf. An additional note is to consider installing subsurface drip irrigation under the new “island tees” in addition to the overhead sprinklers to supply tee-specific watering. This will save a significant amount of water and will eliminate overspray into the turf reduction areas, thus reducing the need for weed control and other maintenance in these areas.
  
  
• The USGA GPS service can identify where golfers are not going on your course. This is a great tool that decision-makers, including the golf course architect, can use to more objectively decide where to remove turf to maximize water and resource savings while minimizing the impact on playability.
  
  
• Turf removal will likely impact play, but the goal is to minimize the impact and have it fit within a desired architectural intent. The relationship between location and impact on play is especially important if the vegetation in these new areas is dense enough to cause extended searches for lost balls. If 80% or more of players navigate the golf course without encountering a turf removal area, that is a success.
  
  
• Turf removal might enhance the challenge and appearance of the course, which could attract new golfers and customers.
  
  

Experience has shown that in many cases it is best to remove turf in phases rather than all in one year. Change is difficult and people are more likely to accept changes to a course if they are implemented slowly and with clearly stated goals and objectives. Begin with a demonstration on one hole or start by removing thin slivers of turf adjacent to the course perimeter. This approach tends to elicit buy-in more successfully than proposing to remove 20 acres or more all at once. It also gives the superintendent an opportunity to gain experience establishing and maintaining these areas on a small scale before moving on to larger areas.

Dealing with existing vegetation

Turn off the water
Once the turf removal areas are identified, you can start the conversion process by simply turning off the water. Golf courses in the West have been able to nearly eliminate cool-season and warm-season turf by shutting off the water during periods of hot, dry weather. I say nearly, because it is always surprising to see warm-season turf such as bermudagrass remain viable without water and even cool-season grasses may remain or regrow when rains arrive.

Some courses have kept it very simple and after several weeks or months with no water have installed decomposed granite or mulch over top of the former irrigated turf. An example is Westbrook Village Golf Club in Peoria, Arizona, where they have removed approximately 6 acres of irrigated turf on the Vistas golf course over the past two years. The process was initiated simply by shutting off the perimeter sprinklers and eventually covering the desiccated turf with decomposed granite. While 6 acres might not seem like much, in Arizona the non-overseeded bermudagrass water requirement is approximately 4.5 acre-feet of water per acre per year. The new landscape at Westbrook Village requires no water and therefore they are saving roughly 27 acre-feet of water annually or about 8.8 million gallons. With no irrigation and an inch or two of decomposed granite on the surface, weed growth is minimal but herbicide applications are still required. While this results in a somewhat barren landscape, it is the least expensive method available to that course and achieves the water savings goal. Some courses have added widely spaced trees and shrubs to turf reduction areas, but these will require irrigation during establishment with the potential to shut off the water once established, depending on the vegetation and climate.

Stop mowing
For some courses, a minimal-management option is to stop mowing turf reduction areas at rough height and start mowing once or twice annually at 4-5 inches. You could also eliminate or significantly reduce irrigation in these areas depending on the local climate. Courses may mow in the spring before plants go to seed, or in the fall before cool-season grasses begin more active growth. While this approach will save resources, over time it may result in significant weed invasion without various management strategies. But, if the goal is to conserve resources and weeds are not a significant concern, this option may be perfectly acceptable.

Sod removal
Some courses elect to remove the sod in turf reduction areas and use it elsewhere on the property if salvageable. The area can then be regraded if necessary and prepared for low-water-use vegetation or capped with some form of aggregate or mulch material. There is a significant time and expense component to removing and relocating or disposing of sod from large areas, but this creates a clean surface for establishing the new landscape treatment. Depending on how aggressive the existing turf is, courses may need to spray regrowth with herbicide after the initial sod removal.
 

Replacement options

This is the million-dollar question. When irrigated turf is removed, what should occupy that vacant space? The land in the turf removal areas still must be maintained to be presentable and functional. Decomposed granite or mulch may serve this purpose well for some courses while others prefer a more natural aesthetic. Some courses have an attractive and functional native landscape surrounding the course and replicating that plant pallet may be the ticket to achieve the turf reduction goals. Others prefer the look of a maintained landscape adorned with colorful flowering plants, but beware of the long-term costs of such a design. Many have been successful with native grasses, woody shrubs and groundcovers.

Whatever the plant material, it should survive on minimal or no irrigation after establishment. Ideally, the plants will be slow growing and low growing such that golfers can locate errant golf shots. Some of the most widely used naturalized grasses planted in turf reduction areas include grama grasses (Bouteloua spp.), big galleta (Hilaria rigida), muhly grasses (Muhlenbergia spp.), bluestems (Schizachyrium spp.), Alakali sacaton and dropseed grasses (Sporobolus spp.), wheatgrasses (Pascopyrum spp.) and fescues (Festuca spp.) – with hard, sheep and blue fescues being the most popular. These grasses vary in their climatic adaptation.

It is best to seek advice from the nearest university cooperative extension office and nearby courses that have planted naturalized grasses. Select a few options that seem promising and plant them at several locations on your golf course and evaluate their performance for two to three years to become comfortable with their performance and management.

Establishing the new landscape

Soil preparation
Selecting plants and native grasses that are adapted to the existing site conditions will typically eliminate the need for soil improvements. Minimal soil preparation is best to avoid bringing weed seeds to the surface and increasing the risk of erosion. Shallow solid-tine aeration is one way to prepare a turf reduction area for planting. “Wheel-tracking” using knobby tires can also help seeds set into the soil and discourage erosion. Another option is to scarify the soil with a harrow rake to create small ridges which helps to prevent erosion and capture moisture. In an environment with considerable weed pressure, it might be best to keep the area fallow for some time before establishing native plants. Allow for weed growth and then eliminate them with a combination of preemergence and broad-spectrum postemergence herbicides.

Seeding
It is critical to seed native grasses and plants into a weed-free, firm seedbed. Weed control efforts should begin well in advance of planting, especially if the existing vegetation is warm-season grass. Use a variety of herbicides with applications spaced over several months and use mechanical means to eliminate competing vegetation. A short-term nurse crop such as annual ryegrass maybe useful to limit erosion and mitigate weed infestation prior to planting the desirable grasses. Eliminate the annual ryegrass prior to planting.

Seeds may be applied through hydroseeding, broadcast seeding or drill seeding. Planting with a seed drill eliminates the need to cultivate the soil and is excellent on slopes and other erosion-prone sites. A biodegradable erosion blanket may be used to reduce the potential for seeds to move from wind or water erosion. The erosion blanket also helps to maintain higher soil moisture and to some extent mitigates weed growth. Mulching helps decrease erosion and preserve soil moisture. Native grass hay is a useful option and is recommended to be applied at 1-2 tons per acre. Crimp the mulch into the soil to decrease hay loss from wind and water. For steep slopes, hydromulch is the best option. Wood fiber mulch applied at rates of 1,500-2,000 pounds per acre is recommended. Many companies will add a tackifier such as a psyllium binder. Think of tackifiers as the “glue” that will bind mulch or straw to an area, preventing seeds from eroding. Capping with sand or a mixture of sand and peat moss or compost can also enhance seed germination through moisture retention and erosion reduction. A 1/8-1/4 inch depth of material is suggested.

Seeding rates should be low to discourage a high density of the newly established grasses. Native grass seeding rates range from less than 1 pound per acre to approximately 15 pounds per acre depending on the seed size. Recommended seeding depths for most native grasses are 1/4-1/2 inch deep. However, some large-seeded species, such as wheatgrasses, can be seeded deeper – between 1/2 and 1 inch deep. Some extremely small seeds, such as many of the dropseeds and muhly grasses, should be broadcast on the surface. A subsequent mulch application will help to keep the seeds in place and offer moisture protection.

Select seed mixtures that mimic the natural vegetation in that area. Utilizing a regional mixture of grasses and vegetation is beneficial because different species will likely perform well during different seasons. Additionally, a regional mixture will have a better chance of survival in the long run compared to non-native species, even if native species are more challenging to establish early on.

Nursery stock (plugs)
Nursery stock may be used to establish naturalized vegetation and grasses in turf reduction areas. This approach, sometimes called “plugging,” is useful in instances where seeds are difficult to establish, or the desire is to produce sparse vegetation with full control over plant spacing. While more expensive than seeding, plugging expedites establishment and maturation, and achieves the desired aesthetic more rapidly than seeding. Plugging also helps establishment where weed competition is fierce and can be more successful than seeding on erosion-prone sites. Plugging also enables more precise weed control with spot applications in between plantings.

Irrigation
Irrigation is likely required for germination and establishment of any plant materials in arid climates. However, it is recommended to time seeding or planting in coordination with anticipated precipitation seasons and apply supplemental irrigation sparingly. In arid climates, spring, summer or early fall seeding dates will require multiple irrigation events per day for approximately 7-10 days to facilitate germination. Decrease irrigation frequency to once per day for the next week, then reduce irrigation to once per week during the remainder of the warm, dry season in the first year of seeding. Consider using a temporary portable irrigation system to assist in the establishment phase if there are not sprinklers located in the turf reduction areas. After the first year of establishment, warm-season native grasses may only need supplemental irrigation once or twice monthly during the summer months, or perhaps none at all. Cool-season species will need more-frequent irrigation to survive the summer months in areas without adequate rainfall. Warm-season species will require soil temperatures greater than 60 degrees Fahrenheit for germination and cool-season species will germinate at a cooler temperature range from 50-65 degrees.

Fertility
No fertilizer is typically recommended for establishing naturalized vegetation. Adding fertilizer often only encourages weed infestation. Consider soil testing and seek advice from the nearest university cooperative extension office for fertility recommendations based on the soil test results and the intended plant varieties.

Adding wildflowers for diversity
Wildflowers can be sown to integrate with native grasses or seeded in localized areas where soil drainage is more favorable. Experience has shown that if the desire is to provide wildflowers every year, supplemental seeding will be necessary, perhaps on an annual basis. Some courses have purchased small hydroseeders to facilitate yearly wildflower seeding. Select mixtures containing annual and perennial species. Weed control is often more difficult in wildflower areas compared to native grasses and managers must rely on preemergence herbicides. Hand-pulling weeds will very likely be necessary.

Demonstrate patience when seeding native grasses
Turf managers are accustomed to fast germination with ryegrass and bentgrass, often seeing new seedlings in less than one week. The same will not be true when seeding native grasses. Native grasses will spend the majority of their energy on root development for the first few years after seeding. This explains why it is common to wait two or three years to see a native grass stand mature. The phrase “sleep, creep and leap” best describes the first few years of the maturation process. Patience truly is an excellent virtue when seeding naturalized areas and this sentiment must be conveyed to course officials and golfers.

How to manage naturalized grassy areas

Mowing
Some courses will mow naturalized grassy areas several times per year, or more frequently depending on growth conditions and weed pressure. Mowing helps to clean up these areas, reduce weed and woody plant invasion and may stimulate desirable grass regrowth. Mowing also improves playability and may speed pace of play. Late summer or early fall mowing can clean up naturalized plantings and encourage cool-season grass regrowth. When mowing yields large clipping volume and thick debris, remove the clippings to facilitate desirable grass regrowth.

Weed control
Weed control can be a big problem in turf reduction areas and may require significant labor resources for both chemical and mechanical control measures. Mechanical control includes hand-pulling, mowing, trimming and chopping down unwanted plants. For woody plants, it is important to treat with herbicide following mechanical removal. Herbicides such as 2,4-D, dicamba and triclopyr are labeled for broadleaf weed control in naturalized areas. Where fescue grass is planted, there are options such as fluazifop (Fusilade II), sethoxydim (Segment) and now pinoxaden (Manuscript) is labeled for use on select cool-season species, including fine fescues. Courses in Northern California that have recently undergone turf reduction projects have had success planting blue and sheep fescue with glyphosate resistance that facilitates weed control.

It is common for native plants to emerge that may help achieve the overall goals of the turf reduction areas even if they were not part of the planting plan. While golfers or adjacent homeowners may perceive some plants to look like weeds, they may help attract wildlife and provide valuable habitat. For example, milkweed is often mistaken as an undesirable plant but has proven to be an important food source for monarch butterflies and their caterpillars. In support of providing habitat for the monarch butterfly, which has experienced dramatic population declines in recent decades, the Monarchs in the Rough program helps golf courses establish milkweed areas. Milkweed and other environmentally beneficial plants can be large and may negatively impact playability if located in close proximity to play areas, so they should be planted or maintained in strategic locations.

Water management
Apply minimal to no supplemental irrigation in turf reduction areas. Irrigation inputs should be reduced after establishment to only supplemental applications when severe drought occurs. Overspray from golf course sprinklers is unavoidable in most cases, but superintendents should strive to minimize the amount of water reaching native areas. Otherwise, thick and overgrown vegetation will develop immediately adjacent to in-play areas. Mowing a single pass along the margin of naturalized areas is a common practice to help address issues associated with overspray. The less water that reaches turf reduction areas, the better they will look and function. Less water means less weeds and less work.
 

Defining expectations

Golfers and homeowners that appreciate wall-to-wall green grass may balk at the “untidiness” of new turf removal areas. As a response, some courses increase the intensity of their weed control programs, using herbicides and labor to manage undesirable plants to an acceptable level. They save water, but dramatically increase the labor cost in these areas when compared to the mown rough that was there before. This is an example of what can come from misguided expectations. It is critical to set realistic expectations prior to starting a turf reduction project. For many courses, the budget is minimal to care for turf reduction areas and the expectation should be set that there will be minimal management.

No matter what the aesthetic and playability goals might be, naturalized areas will take years to mature. Set the expectation that these areas may be minimally planted, with large areas of bare ground. In locations that receive high precipitation, there will be a mixture of desirable plantings, weeds and volunteer plants that emerge. If the goal is a “high-end” look with minimal weeds, set the expectation that this aesthetic will take three to five years to achieve and will require significant amounts of labor and other inputs. A separate crew of two to six employees may be necessary to manage these areas full time, depending on the goals.

There are cases where naturalized areas required nearly a decade to mature into a sustainable landscape. At a course in Scottsdale, Arizona, approximately 75% of the turf removal areas were initially seeded to wildflowers and native grasses. Eleven years later, the areas now consist of 5% wildflowers, 50% native grasses and almost 50% bare ground. Volunteer mesquite and palo verde trees have emerged, some of which need to be removed periodically to preserve views through the property, but the vertical element of these small trees offers varied scale and aesthetics. The combination of native grasses and desert-adapted trees has yielded an excellent habitat for birds and wildlife, and foraging opportunities for pollinators.
 

Concluding comments

There are significant benefits that come with successfully removing irrigated turf and replacing it with a functional landscape that requires little to no water. Aside from the water savings, these areas can reduce overall maintenance requirements when planned and explained properly. Fertilizers, insecticides and fungicides never, or very rarely, need to be applied in turf reduction areas. Mowing requirements are minimal in comparison to irrigated turf. They can provide improved wildlife habitat and add contrast and definition to a property that otherwise may be just a sea of green grass. However, golf courses have found that turf reduction areas can be a significant source of complaints and frustration from golfers and adjacent homeowners if expectations are not communicated or fully met. Before going down the enticing road of turf reduction, the goals and expectations must be clearly stated. When done properly, the results can be exciting and will add tremendous value to the course.