Roots...What Roots? July 14, 2015 By Bob Vavrek, agronomist, Central Region

Shallow-rooted turf on putting greens has been a common sight during recent Course Consulting Service visits.

A long period of time without significant rainfall is called a drought. A one-time deluge of rain is a flood. What do you call weeks upon weeks with no respite from moderate to heavy rainfall? Reverse drought, anti-drought, undrought? In biblical times they called it…”time to build an ark.”

Frequent heavy rainfall across the central U.S. has become much more than an inconvenience, it’s gotten to the point where only 0.25 inch of rain turns a golf course to mush because the soil is constantly at or near field capacity. Important sources of revenue from outside events and cart fees are practically impossible to recover later in the season once they are lost.

Turf is beginning to suffer as much as the bottom line. Turf roots need oxygen, and a considerable amount of root die back has been observed in chronically saturated putting greens during recent Course Consulting Service visits.  Sand-based greens have fared somewhat better than soil-based, push-up greens, but all greens are slowly drowning to one degree or another.

The previous update for the Central Region discussed the importance of venting greens to prevent the further loss of roots. Minimally invasive forms of cultivation like venting will continue to be extremely important as summer begins to heat up. In addition, take the extra time to closely monitor the density and depth of the root system and make adjustments to automatic irrigation and hand watering accordingly.

Many courses that use handheld moisture meters to guide irrigation decisions typically measure moisture in the upper 3 inches of the soil profile, where the majority of turfgrass roots typically are found. However, with the amount of root die back that has occurred, measuring the moisture in the upper 1.5 inch of soil using a shorter set of tines could provide far more useful information.

Shallow-rooted turf is notoriously unforgiving during periods of very hot weather, and only a few hours of moisture stress can spell the difference between live grass and dead grass. No doubt, the table is set for extensive turf loss should Mother Nature decide to add triple-digit temperatures to this season’s mixture of quirky weather patterns.

Source: Bob Vavrek (


Central Region Agronomists:

Bob Vavrek, agronomist –

John Daniels, agronomist –


Information on the USGA’s Course Consulting Service 

Contact the Green Section Staff

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