As summer aeration programs for bermudagrass putting greens nears an end, one trend that gained popularity this year is double aeration. Golf course superintendents, golf professionals, general managers and golfers alike are recognizing that double aeration, if done properly, can achieve agronomic goals while disrupting golfers once, rather than twice, during the summer months. Double aeration will produce twice the amount of holes, but does not require twice the work or twice the recovery time.
A typical aeration program utilizes 5/8-inch outside diameter tines on 1.5-inch by 2-inch spacing and is initiated in June or July with a second aeration roughly six weeks later. The typical program removes approximately 10 percent of the putting green surface area per event, or about 20 percent annually. However, some courses aerate three or four times to achieve the same surface removal with smaller tines. During Course Consulting Service visits, comments that are often uttered include “it seems like the greens are always being aerated,” or “the holes just healed from the last aeration and now you are going to punch holes again?”
Fortunately, double aeration can achieve the goal of removing 15 to 20 percent surface area annually with less disruption to golfers. Double aeration utilizes the same tine sizes and spacing as traditional aeration but includes a second pass oriented at a 30 degree offset from the first. Care should be taken to alter the depth of the aeration tines to avoid a compaction pan. The greens will heal in the same amount of time as a single aeration; however, like other aeration events, it is common to close the course for up to a week to complete this labor-intensive process.
Should you wish to experiment with this technique, begin by vertical mowing in multiple directions followed by applying a generous layer sand topdressing. Aerate the greens using 5/8-inch or even 3/4-inch outside diameter tines on 1.5-inch by 2-inch spacing. Consider using deep tines – e.g., 5 to 7 inches long – for the first pass. Drag aeration cores to recycle sand brought to the surface and blow off organic matter. Roll and brush the topdressing sand into aeration holes and the putting surface. Consider outfitting a roller with brushes to complete this task more efficiently, as seen in the photo. Return with the aerator and make a second pass with shallower tines – e.g., 3 to 5 inches long – but with the same tine diameter and spacing. Again, drag the cores, blow off any organic debris and roll/brush the topdressing sand.
The best time to complete this intensive process is in July or August for bermudagrass putting greens in the Southwest.
Information on the USGA’s Course Consulting Service
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