The greens at Olde Florida Golf Club were constructed in 1992 to USGA Specifications. They were resurfaced in 2000, but the subsurface has never been renovated. As you might have read in my May 21 blog entry, "2021 Golf Course Renovation", the upcoming project will not include a greens renovation. In this entry I will provide more detail on why that decision was reached, and what our plan is moving forward to continue extending the performance of our 27-year old greens.
One of the key components of extending the life of a putting green is maintaining adequate subsurface drainage and soil porosity. This is absolutely vital for the successful management of turfgrass. This has become even more critical as we maintain turfgrass on greens with an intensity, and at heights of cut that were unheard of even 10-15 years ago. If challenges exist with either the drainage or soil porosity, oxygen levels in the rootzone will be low, which can result in turfgrass decline, especially during stressful weather.
While some organic matter in a putting green is beneficial for the receptiveness of golf shots, as well as water and nutrient holding capacity, excessive accumulation will reduce porosity and decrease drainage. There needs to be a healthy balance, and the removal of organic matter through aeration or aggressive vertical mowing, as well as the dilution with frequent sand topdressing are key components of achieving this balance.
Having been hired as we began construction of the golf course in 1992, I was able to monitor the building of the greens. Equally important, I was able to put a summer cultural practice program in place from day one that has enabled us to maintain acceptable subsurface drainage and porosity.
Even through we have properly maintained the greens from the beginning, before making the decision to not renovate the greens in 2021, we had several random selected core samples analyzed by an accredited soil testing laboratory. The reports we received confirmed that the physical properties that influence subsurface drainage and soil porosity are good. While still within the desired range, since the renovation in 2000 we have developed a 7″ layer of organic material on top of the original USGA greens mix.
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| 4" profile taken on 18 green, November 2019 |
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| 4" profile taken on 18 green, November 2019 7" of organic matter has accumulated since the resurfacing in 2000 |
As the pictures above depict, even with frequent aeration, vertical mowing and sand topdressing, organic matter will accumulate over time. Consequently, to extend the performance of mature greens traditional core aeration needs to be supplemented with soil modification techniques that can deposit sand completely through the organic layer. Such processes include Drill and Fill and DryJect. Olde Florida will be incorporating both of these this summer. From May 27 - May 29, a Drill and Fill was performed on the greens, and the DryJect will be utilized during the last closed week of the summer, September 21 - 28.
The Drill and Fill and DryJect processes effectively increase soil porosity and drainage due to the large amount of sand that is delivered deeper into the soil than would be possible with traditional core aeration. For deeper soil modification, the Drill and Fill methods is preferred. When lifted from the subsurface, the drill removes organic matter from the profile, leaving channels that are backfilled with dry, bagged sand. At Olde Florida, a 1” drill bit penetrated the surface of the greens to a 10” depth. Directly into the 10” holes, 168,000 pounds or 84 tons of sand was added to the subsurface of the greens.
This is a YouTube video of the Drill and Fill on 6 green at Olde Florida
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| 4 semi loads of dried, bagged sand were deposited into the greens during the Drill and Fill process |
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| Drill and Fill May 27th on the practice green |
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| Drill and Fill, May 28th on 9 green |
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| Drone shot of 9 green, May 28 |
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| 15 days post Drill and Fill on practice green at Olde Florida |
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| 15 days post Drill and Fill on practice green at Olde Florida |
The DryJect, that we will perform later this summer deposits a similar quantity of sand into the profile, but at a slightly shallower depth and no organic matter is removed in this process.
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| DryJect demonstration, January 2020 on the nursery green |
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| DryJect, January 2020 on the nursery green |
Both of these practices will not be a substitute for standard core aeration at Olde Florida, rather they are treated as supplements. Essentially they are soil modification treatments. In addition to the two processes this summer, we will do three additional treatments in 2021. After 2021, we will perform one annually.
In addition, keeping putting green subsurface drain lines operational is extremely important. This is especially critical in areas like Southwest Florida, where our annual rainfall can exceed 70”.
For the last 27 years, all of the greens subsurface drainage systems at Olde Florida have been checked annually by inserting a 1” hose into the top of the system and running at full pressure until the water leaves the exit pipe.
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| Profile of the USGA Putting Green Construction Method |
