Collar Adjustments

Ball resting against green/collar transition

Last year it was decided to begin taking an aggressive approach toward eliminating the drastic transition from the green to the collar surrounding the green. It was also decided to reduce the width of the collar from two mower passes down to a single pass. Over the last several years, the sand that has been used for topdressing the greens has begun to build-up the collars in such a way that there is now a drastic transition from the green to the collar.  The reason for this is that the collars are mown at a higher height of cut as compared to the greens making it easier for the sand particles to work their way through the leaf canopy leading to less removal from the mowers. On the greens, since they are mown at a much lower height, a higher percentage of sand is removed during mowing leading to less build-up over time.  This transition between the green and collar has now led to a playability issue where it can actually be difficult to putt a ball that is on the green if it is resting against the collar.

Our initial thought last fall was to gradually lower the mowing height of the collar to transition it to greens height, therefore making each green slightly larger and the collar more narrow.  As we began lowering the mowing height on the inside portion of the collar, it became very evident that scalping was going to be a major issue and that a different approach was necessary.

A few weeks ago we began trying a couple different methods to minimize the transition which will allow us to begin reducing the width of the collar. (click on pictures for larger view)

Test #1: Strip Sod

This method will provide immediate results and decent playability but will take a significant amount of time and labor. The process involves stripping all of the collar, removing excess material (soil) to help the new soil level match the level of the green, re-laying the sod, tamping, watering and rolling.  It took three individuals approximately 3 hrs. to complete the process on only half of the big putting green by #1 tee.

Strip existing collar

Remove material to lower the level
of the collar

Re-lay sod in its previous
 location and tamp

Finished product after watering
and rolling

Test #2: Aggressively Aerify the Collar

This method will take a little longer to achieve the desired results, but the process itself is very fast and is expected to take less time and labor to complete.  The process involves 2-3 aggressive aerifications of the collar within a month or two, removing the cores, heavily watering the collar to soften it then driving over the saturated collar with a tractor to lower the level of the collar to the level of the green.  It took two individuals approximately 30 minutes to complete the process on the other half of the big putting green by #1 tee.  Keep in mind that this is not the final result we are wanting to achieve.  This process will need to be done 1-2 more times to get it to the point where it matches the current condition of the collar that was done with the other process.

Drive over saturated collar to begin
lowing soil level

Aerify the collar and a small
portion of the gree

Finished product with holes
remaining open

A couple of points to consider:

Test #1: This is not a perfect process.  Sod seams will be visible and there may be some inconsistencies  with evenness until the sod fully matures (this process is similar to the stripping and re-laying of the sod on #18 green).

Test #2: Holes will be visible for a period of time as we want to encourage the soil to fill the holes leading to additional settling of the collar.  If the minimal amount of holes on the green itself is a concern, we will need to fill them with sand, lengthening the amount of time it will take to achieve our goal.