Boardroom Yarn #50 - 4 Must Take Research Steps Before Rebuilding Greens
Over the past 3 months I have made site visits to seven different golf courses that were considering rebuilding greens and realized that there are a few basic questions that need to be answered before a knowledgeable decision can be made, to first of all justify the rebuilding process and second to what extent the greens need to be rebuilt.
If weak, stressed turf on the existing greens is the reason for the greens being considered for rebuild, then the first step is to find out why the considered greens have weak, stressed turf.
The first step starts with a complete physical analysis of the greens mix and gravel layer.
The second step is to confirm that the drainage system is functioning effectively and to determine where the drainage water drains to.
The third step is to determine if the existing turf is the proper turf for that geographical area.
The fourth step, if the greens have been previously rebuilt, is to determine if the existing greens are sitting on top of previous drainage systems.
Once a thorough investigation has been completed the process of making a decision on wither to rebuild completely including removing the existing greens down to and including the old drainage system or just removing the top two or three inches of existing root zone can be made.
While the course is closed for the rebuild and regrassing, the drain system should be upgraded to include 4-ways with slide valves on all of the drainage out falls/low exit areas, vents should be installed on the main trunk line/lines. Every drain tile that approaches or exits off the green in a high area of the green should also be vented.
It has been a not to uncommon practice in the past to build new greens on top of the old drainage system in order to save a few dollars. This process starts with removing all of the old greens mix down to the drain tiles. Soil is then brought in and compacted to form a new floor base for the new greens. The risk one takes when using this accepted rebuild process is that if the new sub-base ever becomes porous and allows water to penetrate into the old drainage tile system it will result in anaerobic conditions which will produce unwanted and in most cases lethal amounts of sewer gas. [Hydrogen Sulfide, Methane & Co2]
I cannot stress strongly enough the need to find the cause of a greens present weak/stressed turf. In most cases, greens that are being considered for rebuild do not need to be rebuilt.
Copyright May, 2015
David L. Doherty
Dave Doherty is CEO and founder of the International Sports Turf Research Center, Inc. (ISTRC) and holds three patents regarding the testing of sand and soil-based greens. He can be reached at (913) 706-6635 or via email: firstname.lastname@example.org www.davedohertyistrc.com