Country Club of New Bedford Turf Care Center: June 2014

Work has begun on the renovation of the front left bunker on the first hole. At this point the majority of the old sand has been excavated from the bunker except for a small section that we are using as a ramp to get our machinery in and out of the bunker. Overall the process is moving along very smooth without any issue. We were surprised at how much sand was actually in the bunker. In some places the sand was well over 2 feet deep; well above USGA recommendations of 4-6 inches. Also, we were surprised at how much sand accumulated in the face of the bunker over the years from sand being displaced by hitting balls from the bunker. There was just about a foot of pure sand underneath the grass on the face of the bunker. Pictured below you will see sand being removed down to the native soil and the face of the bunker being roughly contoured. Please keep in mind that the bunker is far from complete and the pictures are not entirely indicative of what the shape of the bunker will be when completed.

For those of you who have never seen how topdressing is done I have posted below a couple of short videos of sand being applied and then brushed into greens here at CCNB. After watching the videos you may ask yourself, "why are they putting all of that sand on what looks like a perfectly good putting green?" The Short answer is that top-dressing helps to keep greens firm, fast, and smooth. We all like firm, fast and smooth right? If the short explanation satisfies your curiosity then read no further. However, if you still have your doubts then allow me to explain in a bit more detail.

The science of golf course turf maintenance has evolved and progressed significantly in the past 10-15 years. The USGA green section now recommends that a light sand topdressing be applied roughly every 10 days depending on the speed of turf growth. The primary reason we apply a light sand top dressing in the summer months is to dilute the organic matter in the upper root-zone of the greens. Decomposing or un-decomposed organic matter is one of the biggest nuisances in a green. Among other things, it causes greens to be soft and spongy, and provides a safe haven for a variety of turf pests and pathogens. A frequent and light sand topdressing will aide in the dilution of this organic matter and as a result promote smoother, firmer, and faster greens. It also encourages upright growth and significantly reduces grain in the putting surface.

You may also ask yourself, "why use straight sand as a topdressing material? Wouldn't a material like screened loam be better?". As previously mentioned, the primary purpose of applying frequent and light sand topdressing is to dilute the organic matter in the upper root zone of the greens. Screened loam is a material that contains a high amount of organic matter. It would be poor practice to try to dilute and reduce organic matter in the root-zone by applying a material that contains a high amount of organic matter itself. Furthermore, screened loam has a high moisture holding capacity and as a result would never dry on the surface of a green cut at today’s cutting heights of 1/10^th of an inch or lower. It would stick to the rollers of our greens mowers, smear all over the green, and in general cause a giant mess.

Interestingly enough, many years ago, Golf Course Superintendents actually did use screened loam or calcined clay as a top dressing material. The science of the industry and the availability of proper materials has come a long way since then. 30 to 40 years ago most golf course superintendents were converted farmers and managing turf was a very inexact science. Topdressing with screened loam or calcined clay was commonplace. The fact of the matter is that the maintenance practices and the technology of the time didn't call for other materials to be used. They simply didn't know any better. Hindsight is 20/20 and we have all certainly learned better over the years. I often hear stories from old time superintendents about arbitrarily digging soil out of a pit, hand screening it through a coarse wire mesh, and applying it to their greens with shovels. Judging from the videos below we've come a long way since then right? Through years of university research and trial and error we now know that screened loam or calcined clay are NOT the proper materials to be applying to today's putting surfaces. Today's putting surfaces are often mowed at 1/10th of an inch or less. 30 years ago they were mowed as high as 5/16th of an inch. To put that into perspective, here at CCNB we mow our tees at roughly 5/16th of an inch. The demands and expectations for firmer and faster greens are not subsiding and sand topdressing is one of the most crucial tools that the modern superintendent has to provide this. Simply put, topdressing with screened loam is a thing of the far distant past and given the demands of today's putting surfaces is a very unsound agronomic practice.

Applying sand to the green...