The 100-Day War On Thatch July 5, 2018 By Todd Lowe, agronomist, Southeast Region

It takes a lot of work to make turf look this bad, but it is necessary to remove excessive thatch each summer. This turf will quickly return to playing great.


Recently, golf courses in the southern portion of the Southeast Region have looked like battlegrounds for good reason. Superintendents are battling against thatch with an artillery of aggressive cultivation programs such as deep verticutting, scalping and even fraze mowing – which essentially peels off the entire green leaf canopy of a playing surface.

Superintendent Billy Davidson from the Country Club of Naples calls this summertime cultivation period the “100-day war.” During this time, superintendents wage battle against excessive thatch to recapture premium playing conditions and aesthetics. At the Country Club of Naples, the golf course is closed for two periods during summer so most of the green leaf tissue can be removed and the underlying stem layers thinned out through multiple rounds of coring, verticutting and scalping. This process generates a considerable amount of debris, but it also produces quality playing conditions that golfers appreciate throughout the remainder of the year.

Bermudagrass grows in layers on top of itself. The accumulation of stem material and other organic matter – i.e., thatch – can create soft, inconsistent playing conditions and may negatively impact turf health. With a nearly year-round growing season in southern areas and the nitrogen applied to maintain healthy playing conditions accelerating thatch development, aggressive dethatching is necessary for many southern golf courses every summer. These cultivation practices must take place during summer when weather conditions favor quick recovery for warm-season grasses.

Golf courses that can afford to topdress playing surfaces with sand achieve additional thatch dilution that provides improved consistency and uniformity. If fairways can be topdressed with sand every summer, soil physical properties in the upper rootzone can improve considerably over time.

Generally speaking, the more thatch and organic matter that is removed during summer, the better conditioned a golf course will be throughout the year. Summer closures allow time for necessary cultivation programs and provide good opportunities to implement small renovation projects, install drainage and perform tree work in the absence of golfers.


Southeast Region Agronomists:

Chris Hartwiger, director, USGA Course Consulting Service –

Steve Kammerer, regional director –

Patrick M. O’Brien, agronomist –

Todd Lowe, agronomist –

Addison Barden, agronomist –

Information on the USGA’s Course Consulting Service

Contact the Green Section Staff

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