Yesterday, I posted an article from Boardroom Magazine about greens aerification. In the article, the author refers to "disruptive aerification" which usually refers to punching greens with 1/2" tines or larger and "non-disruptive aerifications" which refer to the use of 1/4" hollow tines. If you look at it like this, at Highlands CC, we do one large, disruptive aeration, followed by 3 non-disruptive aerations and then the first week of November, we DryJect greens two directions. We effectively eliminate the need for an early fall disruptive aeration, because after all, it's the best time of the year to play golf.
There is no set rule for how many times a year Superintendents have to aerate greens. Rather, we follow organic matter data to see how much has accumulated in the top several inches of rootzone. We know that in the top inch, we need to keep that number below 3%. If we don't, a host of other issues can plague the greens. The USGA used to say that we need to affect 20% of the surface each year to keep up with organic matter production. In order to reduce organic matter in the rootzone, we need to impact over 20%. Again, 20% is just the break even point. Anything less, we're losing ground. While this is a very general guide, I personally feel it's a good rule of thumb. In the last 10 years, the USGA has backed off of that for more quantifiable data.
The table above shows the % surface area disruption that various size tines on different spacings will give us.
At Highlands CC, we do the following procedures:
Late March: 5/8" tines on a 2x2" spacing, which disrupts 8% of the surface. Also in Late March, we run the Graden verticutter with 3mm blades, causing another 12% disruption.
Throughout the summer we'll do 1/4" hollow tines, three times a year. This causes 7.35% disruption per year.
In November, we DryJect but that doesn't count for any kind of disruption, because we aren't removing anything, we are just pumping more sand into the system. This is still a very beneficial practice because we're diluting the organic matter we have with more sand. Think of it like we're making up for lost regular topdressings.
In total, we impact 27.35% of the greens surface in a given year. Our commitment to this program is why our greens perform so well after 22 years.
So, in order to avoid a major disruptive aeration in the fall, which is common on cool season grasses, we have to be very aggressive in the Spring. This means hearing some moaning and groaning about the condition of the greens in April. If we decided that the greens had to be more playable in April, we could shift the Graden verticutting to the fall (12% disruption), so the green wouldn't have as much healing to do in Spring. However, the green committees over the years valued the autumn golf experience as more valuable compared to that of spring.
If you have any questions about any of the practices we employ on the golf course, please reach out to me!
