It’s the most basic of cultural practices and yet one of the most complicated. Mowing isn’t anywhere close to running out to the first tee with a Lawn Boy bagger and pulling the ripcord.
Unfortunately, some newbie stakeholders think that it is, and you might spend as much time convincing them that there’s more to it than meets the eye as it takes to mow an entire fairway. Short of putting them in a Star Trek transporter and asking Scottie to beam them to the trade show at the Golf Industry Show, it takes a little skill and a lot of patience to convince them otherwise.
New crew members are much the same. They’re usually well intentioned and eager to learn (otherwise you wouldn’t have hired them), but they still need to be made aware of what could possibly go right and wrong, as well as the complications with machine selection, watering, heat, adjustments, pest control and the various locations on the course.
Location, location, location
The battle cry of the 1970s for real estate moguls was location, location, location. The good ones could explain, and even justify, why a certain property was worth $100,000 more than one just two blocks away – usually referring to traffic flow, scenic views and unique features of the site. Location is certainly important on the golf course for many applications, but especially for mowing considerations. The first and most dramatic is the function of the site.
Each functional area – greens, tees, fairways, rough and deep rough – have been designed to be mowed at an optimal height. Though each course is different, certain locations within each grouped area can also be predetermined to be cut at a different height as well.
Knowing these specifics well beforehand and making adjustments accordingly is foundational to maintaining each site at the optimal height. Instructional discussions that take place during team meetings at the beginning of each day should cover these essentials, as well as the specific pieces of equipment to be used.
Drilling down to individual spots on the course pays off when it comes to locations as well. In certain situations, these sites are called microclimates – places that are different from the rest in terms of sun or shade, wind direction and velocity, slope, drainage and wear patterns. Each of these and more influence the rate and density of growth and, therefore, the interactions with mowing.
For example, bright sunshine encourages healthy, rapid turf growth as long as the roots are moist and adequate nutrients are available in the soil solution. Turf on shady tees, greens and fairways may grow as quickly as sunny locations, however, rarely as dense. Also, shadier turf often is infected with various fungal pathogens such as powdery mildew and leaf spot.
Turf that grows on slopes often develops a thinner canopy due to lesser capacity for retention of root moisture. Under these circumstances, drag on the mower reels is often reduced. Whenever turf has a greater than 5 percent slope, the potential for slippage and wheel damage is high. Special attention should be paid to these sites to prevent injury from wear and tear.
Windy sites often develop in a similar fashion to sloped ones, although seasonal changes usually influence potential changes to a significant degree. Poorly drained sites are often damaged from mowing operations as well. These areas can be muddy when closely adjacent spots are not, requiring the mower operator to look closely to the soil or turf surface for sudden changes in the turf appearance.
Finally, the tee or green layout is an important factor. Long, wide and open arrangements tend to be more tolerant of mowing and wear damage than tightly confined ones. Under certain circumstances, it may be necessary to work with an architect to redesign problematic locations.
Fertilizer application, especially nitrogen, greatly affects several components of mowing height management because of the relationship between N and shoot growth, density and root growth. Harkening back to the ’70s once again, superintendents have reduced amounts of applied nitrogen over the years to produce leaner, thinner canopies with the goal of increasing ball roll speed. This has been accomplished through light applications, or spoonfeeding to provide only what is needed by plants to recover from stress.
Frequency and nitrogen source also can interact with mowing as well. Generally, readily soluble forms such as urea and ammonium nitrate create a quick growth response, whereas slow release forms produce an even greening effect. As with location influences, thinner canopies produce greater opportunity to recycle turf clippings to the stand without the disruption of golf play.
Plant growth regulator (PGR) applications have been shown to affect several dimensions of turf plant growth including vertical growth, shoot density, rooting, disease or stress recovery and drought tolerance. When applied appropriately, a significant reduction in clipping production and scalping is achieved, which are both highly desirable.
However, when PGRs are applied at an excessive rate or even too often at a low rate, turf may become over-regulated, leading to poor quality and a restricted capacity to recover from mowing damage, pathogen activity or heat stress. Generally, PGR application should be targeted toward reducing surges in leaf growth, which commonly occur in spring on cool-season turf and early summer on warm-season species.
Along with mowing and fertilization, irrigation is one of the most foundational cultural practices that influences turfgrass growth. Overall, moist root zone conditions favor desirable turf shoot growth and, therefore, influence mowing operations.
The key to this guideline is in the definition of moist and the rate of depletion and retention of the soil components. In the instance of fairways, most are comprised of native soils, containing a significant fraction of clay, which serves to hold soil moisture tightly once saturated. Greens, on the other hand, are commonly highly modified to reap the benefits of high-drainage capacity.
These disparate sites and soil components dictate how often and how much water is applied to keep the roots moist and able to replace the water that is lost to the atmosphere through evapotranspiration and that which is utilized by the plant for growth – more light, frequent applications for greens and fewer but heavier applications for fairways.
As with any procedure on the golf course, several challenges exist with mowing. Some of the more common ones are equipment malfunctions, lack of proper maintenance and weather issues. Hopefully, the number of times that stakeholders ask about “those brown lines” in the green, referring to hydraulic leaks, are few. Checking the status of lines in age and flexibility before mowing is helpful in reducing problems.
Golf mower equipment should be sharpened frequently. Failure to sharpen frequently, or properly, leads to torn, rather than cut, turf blades. This can facilitate the entry of pathogens into the plant as well as create a drag on ball roll.
A challenge that is out of the control of the superintendent is the weather, particularly wet and stagnant conditions, preventing regular mowing. Under these conditions, excessive growth occurs, making it difficult to follow the one-third rule, which encourages removal of less than a third of the foliage with any one mowing operation. Keeping an eye on the weather forecast and adjusting worker schedules accordingly helps in this regard.