Verticutting and Sand Topdressing

Last week we went through the process of verticutting and topdressing our putting greens and I’d like to explain the reasoning behind this.

Verticutting is the use of vertical cutting blades, similar to small circular saw blades, to cut the turf horizontally. This can benefit the putting surface in the following ways:

• It removes lateral shoot growth promoting an upright growing turf stand.
• The energy the plant used to support the lateral shoots can be directed back to the upright shoots and, hopefully, the root system.
• It can increase putting speeds and provide a smoother putting surface.
• It opens the turf canopy allowing topdressing to be worked in. This is very important as we grow in the newer and more aggressive varieties of bentgrass.

Some golf industry professionals would include additional sunlight as a benefit from verticutting but I believe this benefit is minimal and short-lived.

The picture below shows an example of a verticutting unit for a riding greens mower. These units are attached to the mower in place of the normal cutting units. The green is then verticut in the same manner that it would be mowed. This process is immediately followed by a greens mower which picks up the debris removed from the putting surface.

 

 

Once the putting surface is clean of debris, we begin the topdressing process. Topdressing is the application of a thin layer of kiln dried sand which is brushed into the canopy through the channels opened by verticutting. This process benefits the putting surface in the following ways:

• The sand works its way into and dilutes the thatch/organic matter found in the soil profile directly below the canopy.
• It results in a firmer and smooth putting surface. These two traits directly impact the speed of the greens.

Inconsistent and insufficient sand topdressing will result in excessive organic matter accumulation in the soil profile. Excessive organic matter is perhaps the most detrimental characteristic of greens that underperform during the heat and stress of the summer months. Soil with too much thatch/organic matter lacks the ability to drain water and exchange gasses effectively. This results in a compromised root system that is unable to support the turf through periods of stress. The symptoms of excessive thatch/organic matter are also expressed through soft, spongy, and puffy greens surfaces that result in a poor putting surface.

Over the past four years, I have implemented an intense verticutting and topdressing program in hopes of battling the thatch/organic matter that has accumulated in our greens profile. Verticutting and topdressing will take place every 2-3 weeks throughout the spring and into early summer. At the onset of hot summer temperatures, we will remove the verticutting from the process and rely on lighter, more frequent topdressing. This will continue until cooler fall temps allow us to add verticutting back into the fray.