COURSE CARE
Standing Tall February 27, 2015

Standing Tall

By Ty McClellan, Agronomist
April 18, 2008

Due to a prolonged winter, spring across the upper Mid-Continent Region has been delayed by as much as two to three weeks. Many have yet to mow the putting greens more than every other day, which is approximately half as often when compared to a typical mid-April schedule. Cooler than normal temperatures have certainly slowed bentgrass growth, but this does not prevent golfers' desires for greens conditioned at optimal playing conditions, particularly after the best teed it up at Augusta National last weekend. In response to these expectations, superintendents may entertain thoughts of lowering the putting green height of cut much too quickly and too aggressively. Common questions posed during this early part of the season include " When and how quickly should the height of cut be lowered?" and "When should it be raised again to maintain turf health and avoid summer heat stress?"

As consideration is given to the conventional practice of lowering the height of cut in the spring, raising it again during the summer, and followed by lowering it in the fall, why not always maintain a higher mowing height so as to take advantage of increased leaf tissue all season long? Why deplete carbohydrate reserves and weaken the turf with ultra low mowing heights heading into summer when we can instead prepare for summer by achieving deeper roots that increase recuperative potential and stress tolerance during the fall and spring? By considering the following rolling strategies, up, not down, is the direction for putting green heights of cut this year:

  1. Target rolling , also referred to as site or tournament rolling, is gaining popularity across the region for good reason. It ensures maximum surface smoothness, trueness of ball roll, and increased green speed on a daily basis where it is most noticeable…..around the hole. For more information on target rolling to preserve turf health without sacrificing playability, see the article Green Speed: Trick or Treat? by clicking on or entering the following website address - /content/dam/usga/pdf/imported/060717.pdf .
  2. Consider alternating mowing and rolling (as opposed to mowing everyday) to save valuable budget dollars and man-hours, while improving turf quality without adversely impacting playability. While the University of Tennessee originally researched this practice with regards to preserving turfgrass health during the heat of summer, it is gaining popularity as a season-long practice.
  3. If neither strategy fits your situation, consider developing a hybrid of the two or create your own rolling strategy that best matches your needs and resources so that you can utilize rolling to bump up those mowing heights all season-long.

Note: Rolling can be stressful to turf health and therefore should not be overused, especially during the summer where it may be most detrimental. Generally speaking, an entire green should not be rolled more than three times weekly if performed in addition to daily mowing. As such, utilizing rolling in a target manner or alternating mow-roll practices makes sense when it comes to maintaining smooth, fast putting surfaces without sacrificing leaf tissue.

In maintaining healthy turf, it is important to remember the following:

  • Research shows that even small increases in mowing height, i.e. mowing at 1 / 8 to 5 / 32 of an inch, can vastly improve turf quality through a 25% increase in photosynthetic potential and increased root mass. Furthermore, root mortality and summer bentgrass decline are mitigated by minimizing the duration in which plant respiration exceeds photosynthesis in mid-summer.
  • Taller turf helps ward off invasion by moss and weeds.
  • Increased leaf tissue is especially beneficial when a green is shaded and solar radiation is limited.
  • Light, frequent topdressing applications (i.e. summer dustings) are more easily worked into the turfgrass canopy.
  • And, despite the unpopularity among all involved, routine topdressing and aeration are still necessary for long-term putting green health and playability.

To attain the best results when utilizing any of the rolling strategies discussed above, the following are recommended:

  • Use plant growth regulators (PGR's) as they are very helpful in maintaining more consistent green speeds throughout the day and from one day to the next. For greens comprised of more than one turfgrass species, variety or cultivar, PGR's also minimize the differences in the varying growth rates.
  • Avoid flushes in growth by applying nitrogen frequently and in low amounts, such as 0.1 lb N every 7-10 days in a water-soluble, quick-release carrier.

All things considered, think again before instinctively lowering the height of cut this spring only. For your turf to benefit all season-long, it is worth maintaining the maximum height of cut (without sacrificing playability) so your turf can stand tall when it matters most.

If you would like more information about a Turf Advisory Service visit, do not hesitate to contact either of the Mid-Continent regional offices: Ty McClellan at tmcclellan@usga.org or (630) 340-5853 or Bud White at budwhite@usga.org or (972) 662-1138.