COURSE CARE
Only You Can Prevent Scalped Bermudagrass Greens April 15, 2013 By Brian Whitlark

An experiment conducted on this Miniverde bermudagrass green revealed that no cultural practices or aeration alone resulted in elevated thatch and eventual scalping (left portion of this green). However, a combination of verticutting and topdressing decreased thatch and prevented scalping (right portion of green).

Proactively managing bermudagrass in the early spring can help prevent excessive thatch accumulation that often results in scalped putting greens. 

With a third of the year already behind us, it is important for turf managers that have not been actively managing thatch on bermudagrass putting greens to kick it into gear before conditions go sour during the summer. Historically, thatch management tactics such as verticutting, grooming, topdressing and brushing are delayed until May or even June on overseeded or non-overseeded bermudagrass greens in the Desert Southwest. Such practices have been omitted to avoid disruption to play during the prime golfing season. This approach is flawed for several reasons: 

  1. These cultural practices are not disruptive to play if the equipment is set appropriately.
  2. Stolon and rhizome growth continues at a slow pace during the first few months of the year, despite the cold weather and competition from overseeded turf. As a result, thatch accumulates and will become excessive in the absence of cultural practices.  
  3. Delaying cultural practices such as grooming, brushing and verticutting encourages a dense, cool-season grass mat if overseeded, and may result in poor transition. 

If cultural practices have been delayed this year, begin topdressing, grooming, verticutting and brushing right away. If such practices are delayed too long, the bermudagrass may become soft and spongy and will scalp once more humid weather arrives in July. Here are a few tips to initiate these cultural practices without disrupting play during the most important revenue months of the year: 

  • Brushing can be utilized throughout the winter months and can increase in frequency once growth ensues in late January and early February. Use one of the new front-mounted brushes on the market or a gear-driven brush.
  • Grooming can begin about the time of the Superbowl, or even sooner, depending on the weather. Begin by setting the blades only a fraction of an inch below the current mowing height. Progressively lower the blades into the canopy as growth increases.
  • Verticutting can begin once the greens produce a regular clipping yield in the spring. Set the blades shallow initially at 0.050 to 0.060 inches below mowing height. This will not disrupt play and will slowly thin the stand of overseeded grass.
  • Topdress lightly and frequently. Sand should be applied at 0.5 to 1.0 pounds per 1000 square feet every week or twice monthly. Light rates applied on a frequent schedule are less likely to disrupt play and will provide agronomic and playability benefits.

Remember that delaying important cultural practices may lead to puffy, scalped greens in the late summer. Avoid scalped greens by utilizing light and frequent cultural practices beginning in the early spring and continuing throughout the summer.

Source: Brian Whitlark (bwhitlark@usga.org)

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