Collars, Contamination And Simplicity December 7, 2018 By Steve Kammerer, regional director, Southeast Region

Without regular perimeter edging, these three bermudagrass varieties became severely contaminated only two years after establishment.

Typically, putting greens in the Southeast are a variety of either ultradwarf bermudagrass or creeping bentgrass surrounded by bermudagrass rough. Collars, between these two playing surfaces, get exposed to a lot of abuse and is prone to developing many problems. Common collar issues include wear and a gradual increase in elevation caused by frequent sand topdressing. However, preventing putting green contamination is another serious challenge associated with collars. Vigorously growing bermudagrass can quickly encroach into putting greens, requiring diligent management to prevent widespread contamination.

Using a variety of bermudagrass for collars that is different from both the putting greens and rough is gaining popularity. However, this approach has its own issues. The bermudagrass varieties that are typically established in putting green collars are often more aggressive than putting green varieties, so collars – which act as a buffer that prevents contamination – can actually present an additional threat. Furthermore, if the collar perimeter is breached by the bermudagrass variety in the rough, it will encroach into the green as if there was never collar in the first place.

Having three different turf varieties in such a small area adds even more complexity to an already challenging area for golf courses to manage. These different turf varieties may have varying tolerances to growth regulators, wetting agents, fungicides and cold weather. Additional labor will also be required to prevent the rough from encroaching into the collars. For simplicity’s sake – and to save time and reduce management headaches – use the same grass variety in putting green collars and roughs. It’s far easier to fight a battle against contamination on one front rather than two.


Southeast Region Agronomists:

Chris Hartwiger, director, USGA Course Consulting Service –

Steve Kammerer, regional director –

Patrick M. O’Brien, agronomist –

Addison Barden, agronomist –

Information on the USGA’s Course Consulting Service

Contact the Green Section Staff

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