When a golf facility undergoes a putting green renovation, many golfers envision flawless conditions when the putting greens reopen. The process of going from bare soil to a pristine putting surface brings incredible excitement and high expectations. Unfortunately, conditions often are not as perfect as golfers or the superintendent would like in the weeks and months after new putting greens open for play. It takes time for young turf to mature, and it is perfectly normal to observe isolated areas of thin turf, especially near the edge of a putting green and in the collar.
The edge of a putting green– sometimes referred to as the cleanup pass – and the collar that surrounds the putting surface are two of the most challenging areas on a golf course to maintain. The turf in these areas is routinely subjected to stress from the starting, stopping and turning of mowers and rollers. If not carefully managed, traffic stress can lead to significant turf injury and poor playing conditions. Concentrated traffic has a pronounced effect on newly planted putting greens because they often lack a thin mat layer that provides resiliency. Compounding the issue is the fact that because collar turf often grows more laterally, has wider leaf blades and is not as dense as putting green turf, it is actually more susceptible to equipment abrasion and injury.
To reduce the likelihood of turf injury, it is quite common to omit collars while new creeping bentgrass putting greens are established. This gives young turf time to develop a sufficient mat layer and helps simplify mowing operations. Once the turf has matured – typically after one year – the height of cut can be increased to create the collar. Another option is to never establish a collar at all. Not having a collar eliminates the need for an extra mowing operation and potentially provides a few extra hole locations that would not have been available otherwise.
Building a new putting green is an intensive process, similar to a major surgery. It is important to remember that successful construction and establishment does not mean that everything will be perfect initially. Just as a patient is sore and has a few scars from an operation, it is completely normal for a new putting green to have some weak areas and a few blemishes. As the turf continues to mature and develop, fragile areas around the putting green perimeters will become strong and the scars will fade away. However, just because the turf has completely matured doesn’t mean that these symptoms are gone forever. Concentrated traffic combined with extreme weather conditions can cause turf injury or thinning no matter the age of the turf.
Source: Dernoeden, Peter H. Creeping Bentgrass Management: Summer Stresses Weeds and Selected Maladies. Wiley & Sons, 2002.