From Grow-In To Golf – A Tip For Keeping Collars Under Control September 30, 2014 By Chris Hartwiger

(L)White golf course marking paint was used to clearly define the boundary between this ultradwarf bermudagrass putting green and the bermudagrass collar. (R) The larger bermudagrass plant inside the yellow circle has crossed the white line and is easy to spot. It will be removed by hand.

The final few weeks before reopening a golf course following a putting green renovation is an exciting and busy time for golf course superintendents. The quality of the putting surfaces improves almost daily as mowing frequency increases and height of cut decreases. However, not all the grass wants to stay in place. In this update, we share a tip that Mr. Stephen Miles, golf course superintendent at The Preserve in Vancleave, Miss., used to manage bermudagrass encroachment into his new ultradwarf putting greens.

The Issue:  Bermudagrass Encroachment  

Bermudagrasses used on collars often are more aggressive than the bermudagrass or bentgrass cultivars planted on the putting greens. When fertility programs are supercharged during grow-in, bermudagrass can quickly move from the collars into the putting greens. Over time, this will lead to a decrease in putting green size and potentially a loss of hole locations. Therefore, it is desirable to begin managing encroachment early in the life of a new putting green.

The Solution: Define the Edge  

In addition to higher fertility, there are at least two other reasons why bermudagrass aggressively encroaches into new putting greens. The first is the difficulty of mowing precisely to the edge of the collar. It is no small task to mow exactly at the collar/putting green interface. The second is a lack of competitiveness from the new putting green grass. Putting green fertility is always higher during a grow-in. Inevitably, the collars receive much, if not all, of the extra fertilizer applied to putting greens during grow in. The additional fertilizer helps promote the lateral growth of bermudagrasses used on collars and intensifies the potential for encroachment.

At The Preserve, Miles used white golf course marking paint to paint a line along the perimeter of each green. This clear delineation was helpful to the mower operators and allowed them to precisely mow to the outer edge of each collar. The line also helped staff members responsible for edging see where the intended perimeter of each green was and if any bermudagrass from the collar was encroaching into the green. In other words, bermudagrass runners were easier to spot.

The Results:  Excellent Definition at the Time of Opening  

Miles’ course is scheduled to open in early October and he was pleased with the results of his strategy to manage encroachment. Miles remarked that the bermudagrass runners were much easier to spot and the staff was able to remove them by hand before the runners had an opportunity to tack down. As the opening date neared, Miles stopped painting the white line in hopes that by opening day the line would no longer be visible but an excellent definition between collar and green maintained.

Source:  Chris Hartwiger ( and Patrick O’Brien (

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