skip to main content

Key Takeaways

  • Topdressing fairways has many potential benefits, but it is expensive and can have unintended consequences if not implemented properly.

  • The ideal sand for fairway topdressing is usually coarser than the sand used for putting greens. However, you may need to switch to a sand with fewer coarse particles.

  • To minimize layering, fairway topdressing should be integrated with cultural practices like core aeration that bring native soil to the surface where it can be mixed with the sand and reincorporated into the canopy and rootzone.

  • Some areas of your course may benefit more than others from fairway topdressing. You can focus on the areas that need it most and expand the program as desired.

     

Applying sand topdressing to fairways is a long-standing practice. Many golf courses have been topdressing fairways for years and many others will consider implementing this practice. There are many potential benefits to playability and turf health from topdressing fairways, but there are also many obstacles that need to be avoided for success.

The goals of a fairway topdressing program are to dilute organic matter and improve firmness and smoothness. Creating a smoother and firmer surface will help the fairways tolerate traffic, provide good bounce and roll, and simply give a good lie. Those benefits are worth pursuing, but it’s important to recognize that an effective fairway topdressing program is a significant investment that must be made over many years to be successful. Before making that kind of commitment, you’ll want to know whether fairway topdressing will be worthwhile at your site and how to implement a successful program.

When and where should you consider fairway topdressing?

If your course already has well-draining soils and adequate drainage infrastructure, then adding sand topdressing to the fairways may not provide any improvement in surface firmness or turf health and can be a waste of resources. If the fairways drain slowly and you frequently have soft playing conditions, golf cart restrictions and issues mowing when necessary, then sand topdressing applications can be beneficial.

Sand topdressing will not be much help if you are trying to fix areas that hold water after rain. Installing drainage and/or recontouring the surface are the only ways to fully address these issues. When the soil physical characteristics prevent adequate water infiltration and create soft conditions throughout the fairways, then sand topdressing applications should be considered. Introducing sand topdressing into heavy soils will modify the growing medium to increase air- and water-filled porosity. The goal of the topdressing program is to create a better growing medium with minimal disruption that eventually looks like dirty sand.

Another consideration is to evaluate if every part of every fairway would benefit from sand topdressing. Often, golf courses have just a few fairways with poorly draining soils or low-lying areas that would improve with regular spot treatments of sand topdressing. If budget is a limiting factor, you can be selective and focus the topdressing program where it is needed most.

Fairway firmness is dictated by physical soil characteristics, organic matter (thatch) accumulation and volumetric water content. Let’s begin by discussing each factor as they relate to the playability and turf health of fairways and how a topdressing program can best improve these characteristics.

Improving physical soil characteristics

The first step in planning a fairway topdressing program is to assess the physical characteristics of the existing soil profile. One of the key elements of a firm surface is having a wide gradation of particle sizes. If the existing profile contains higher concentrations of fine particles such as silt and clay, then introducing larger-particle-size sands through topdressing will improve the physical characteristics. Incorporating these particles into the existing rootzone helps the soil pack together more firmly, improving stability. As the larger sand topdressing particles are mixed into the rootzone over time, they will increase porosity, which improves water infiltration.

This balance of broadening the particle size distribution and increasing porosity can be challenging to achieve. Moderate annual sand topdressing rates of 60-90 tons per acre seems to effectively incorporate sand particles into the rootzone and dilute organic matter accumulation. Applying more aggressive annual rates can lead to problems resulting from heavy sand topdressing not being incorporated or mixed into the existing rootzone material, thereby creating layering issues leading to a decline in turf health.

Sand selection is very important. Using fairway topdressing sands that are not widely graded can lead to softer fairways. Another concern with aggressive sand topdressing is that it can bury a thick organic matter layer that is currently at the fairway surface. Adequate aeration must be performed to break through this layer if present and allow sand topdressing to mix deeper into the soil profile. I have seen issues with a buried organic matter layer more often in warm-season fairways where regular core aeration is not performed, but it can be a problem in cool-season fairways when only solid-tine aeration (or no fairway aeration) is performed.

When only solid-tine aerating, the rootzone is minimally disturbed and native soil is not brought to the surface where it can be blended with the topdressing sand. By not adequately mixing the native soil and sand topdressing, the widely graded particle size distribution necessary for firm surfaces is not created. In this scenario, you may get a false sense of progress while the new sand topdressing layer is shallow. The fairways will become smoother and organic matter is diluted, which can give a short-term improvement in firmness. Roots and water will also still move into the previously existing rootzone below. When the sand topdressing layer grows to a depth where typical aeration does not pull the existing rootzone material to the surface anymore, an increasingly sandy layer will develop. If this sand is not blended with the native soil through some form of cultural practices, problems will develop.

Addressing an organic layer

If the fairways have a thick layer of organic matter, it will hold water and create soft conditions. This will contribute to other maladies such as high disease pressure, susceptibility to scalping, tire track damage from golf carts and plugging golf balls. Piling sand atop a thick organic matter layer will bury the problem and cause more problems later. If you plan to begin a fairway topdressing program, excessive organic matter accumulation should be first combated with an aggressive combination of core aeration and deep vertical mowing through the thatch layer to the native soils. Test annually for organic matter in the top 2 centimeters to monitor progress. During these cultivation practices, applying sand topdressing is valuable, just ensure the thatch layer is getting diluted and not buried. This scenario may justify a short-term sand topdressing program. When the excessive thatch is controlled, sand topdressing applications can be discontinued but strong cultivation practices to thoroughly mix the sand topdressing into the existing rootzone and keep up with organic matter accumulation are required.

"Piling sand atop a thick organic matter layer will bury the problem and cause more problems later."

Moisture management

The third key component of fairway firmness is volumetric water content (VWC) in the rootzone. This is the most changeable factor in the short term. When sand topdressing is incorporated, the increase in soil porosity will encourage water movement through the profile, which will decrease moisture content and improve firmness. However, topdressing has minimal impact on surface drainage. As mentioned earlier, areas that actively hold water after a rain storm will not improve with sand topdressing applications. Installing drainage and/or regrading the surface is needed to remedy these issues. If an entire fairway or large areas of a fairway retain excessive moisture, then sand topdressing in conjunction with adding internal drainage will improve firmness and turf health.

Another case where sand topdressing can help you manage VWC in the soil is when shallow rock or a high water table is present and sand capping is not possible. In these cases, water management is challenging and raising the fairway elevation is necessary. Committing to applying 60-90 tons per acre per year for a minimum of 7-10 years will be necessary before the benefits are realized. This will essentially create a sand cap over time. This scenario often applies to just a few challenged fairways, so sand topdressing may not be needed across the entire course to address a localized issue.

Sand selection

Sand selection will play a key role in surface firmness. If a narrowly graded, rounded sand is used, infiltration rates may improve but the surface will not stabilize, which may not give the desired playability. Selecting the best topdressing sand can be challenging and balancing cost versus quality is a real issue. Often, it comes down to what is available. Focus on finding a subangular sand that is free of silt and clay and has minimal very fine and fine particles. The ideal fairway topdressing sand is usually coarser than a typical putting green topdressing sand. The goal is to mix finer native particles with the coarser sand topdressing through aeration and other cultural practices.

Over time, as the topdressing layer builds up, it may be necessary to change the topdressing sand. This will depend on how well the native soils are mixed into the topdressing layer. Eventually, the topdressing layer will build to a depth where the native soil is no longer pulled to the surface during regular cultivation practices. At this point, new sand topdressing will not get the native soil mixed in for proper stability and a sand with a wider gradation of particles should be used or the topdressing program should be suspended. If continued fairway topdressing is desired, quality control becomes more important as the sand topdressing now should include some finer particles.

A study at Michigan State University completed in 2001 evaluated the stability of sands with varying particle size distributions as well as small additions of silt and clay. The sands with narrowly graded particle sizes exhibited low frictional forces between the particles and had a low coefficient of uniformity (Cu) and low stability. The sands with widely graded particle sizes had a higher Cu and gave double the stability. When 10% of a sandy loam textured soil was added to the high-Cu sand, the stability doubled again. This shows the importance of changing to a widely graded sand topdressing to achieve firmer playing surfaces once the native soils are no longer mixed in.

Incorporating the sand

In the early years of a fairway topdressing program, adequately mixing the sand and native soils is fairly easy through regular core aeration. The aeration cores pull native soil to the surface where it can be broken down and redistributed. Sand topdressing should be applied before or just after core aeration for improved mixing of the sand and soils. Any sand topdressing applications that don’t coincide with fairway aeration should also be worked into the turf canopy as much as possible through dragging or other processes. Keep an eye on sprinklers and quick couplers as they can be adversely affected by the sand. Problems can be avoided by hand blowing the sand off the sprinklers and quick couplers while it is still dry.

After the sand topdressing layer reaches a depth where shallow core aeration no longer pulls native soil to the surface, it will become increasingly sandy with additional topdressing. There are machines you can use to reach deeper into the profile to continue pulling native soil to the surface. They are called recycling dressers and are available through a few manufacturers. These machines aerate vertically with blades going as deep as 7 inches and bringing the underlying soil to the surface, redistributing it as a topdressing. The cleanup process after using one is similar to core aeration, you drag the area with a steel mat or brush and clean up any excess debris.

This practice should be considered at courses that have applied topdressing for years and developed very distinct layers of sand and native soil. Assuming the sand topdressing layer is less than 7 inches deep, these recycling dressers will break through this layer like linear decompacting machines with the added benefit of slicing at different depths while pulling deeper, native soil to the surface. Water infiltration is significantly improved and organic matter accumulation is also diluted. These machines work well on fairways that have built up a desirable depth of sand topdressing but need further blending of the rootzone.

A few challenges to be aware of

If you are thinking about starting a fairway topdressing program but are not sure about going all-in, start on a smaller scale. Choose two or three fairways that would most benefit first. This will allow you to develop a process that works at your golf course. Don’t be surprised to encounter some challenges along the way. Space to hold the sand prior to application can be an issue, so figuring out how to quickly spread the sand while working around the constraints of the golf calendar needs to be sorted out. Most courses have a topdresser for putting greens, but you’ll want to use a topdresser with a much larger capacity for fairways. Another issue is incorporating the sand into the turf canopy with steel, brush, or cocoa drag mats. Steel drag mats work great, but they can be abrasive so you may want to use gentler methods during potentially stressful times of year. Try different methods to see what works best at your course. When sand topdressing is not well incorporated into the turf canopy, mowers will harvest some of the sand you just spent so much time and money putting out. Mowing without baskets will reduce sand removal but the bedknives and reels will endure significant wear regardless. Localized dry spot will increase with more fairway topdressing. If wetting agents and hand watering were not a big part of your program in the past, the need for both will likely increase as well.

Topdressing fairways for improved turf health and playability could be beneficial at many golf courses, but it is expensive and can create agronomic issues if not implemented carefully. When properly performed, the rootzone physical characteristics are modified to optimize water infiltration and increase stability, leading to healthier fairways that play better and are more reliable throughout the year.