Two important cultural practices were completed recently on the greens. First, a deep-tine aerification was performed in late November(see post on deep tine aerification). Second, topdressing with coarse sand was completed in early December. The result will help to provide firmer, more consistent greens for the 2012 season.
A deep tine aerification differs from a typical one in that the tines penetrate into the green deeper (10-12 inches versus 3-4 inches.) As a refresher, turfgrass roots will develop no deeper than the level of sustainable oxygen in the soil. Over time, a layer can develop at the three-to-four inch depth making it harder for a gas exchange to take place between the deeper layers of the soil and the atmosphere. The end result could be shallower rooting of turf which could ultimately affect playability. The deep-tine aerification, therefore, is critical to minimizing or preventing any undesirable layering from occurring.
Sand topdressing was completed soon after the deep-tine aerification. In this case, the goal of topdressing wasn’t necessarily to fill the aerification holes with sand. In this case, topdressing was aimed more at opening up or diluting the layer of organic material that inevitably builds up in the upper levels of the greens. For the record, we used about two tons of sand per green.
It’s important to realize that not all topdressing is the same. Particle size, shape and hardness, are important aspects to consider when selecting the best topdressing for an application. We are fortunate to have access to hard quartz silica sands in this area which are quite durable. Correct particle sizing is critical when selecting topdressing. The general rule is never to topdress with a smaller particle size than the green was constructed with. Over time finer sand will tend to clog the green and make it more difficult for water and air to percolate down into the root zone. Therefore, the greens were topdressed with a coarse material.
The difficulty of topdressing with coarser sand however, is that it doesn’t work its way into the green’s canopy as efficiently as a finer material would. During the growing season, when we are mowing every day, this is an issue since the mowers tend to pick up and remove the sand long before it enters the canopy and begins doing its job. Since we’re not mowing the greens at this time of the year, we decided to topdress now and allow the material time to gradually work its way into the canopy. When we mow again next season, the topdressing will have incorporated and will prove beneficial for years to come. The end result will be firmer, healthier and more consistent greens next season.