Aerification is one of the turf industry’s dirty jobs. However, despite years of technical advances in the field, aerification remains a necessary task for turf health.
Sub-par greens will render your best efforts elsewhere on the course as meaningless. And quality greens cannot be accomplished without periodically opening the soil, says Chris Hartwiger, who directs the USGA Green Section’s course consulting service and has been with the group for more than 20 years.
However, today’s economics minimizes the time a course is shut down during the aeration process. “We’ve seen an adjustment in how people have maintained their putting greens, specifically with aeration, over time,” says Adam Moeller, director, USGA Green Section Education. “There has been an emphasis to scale back on the number of aerations a year for fear that they’re going to get golfer complaints and ultimately lose the revenue.”
Superintendents are increasing the interval between aerations, says Jeremy Opsahl, Toro’s global product manager. “Rather than doing two or three treatments in a year they might do it in one or two,” he says.
At the same time, superintendents are punching more and larger holes in their greens. For example, Toro now offers superintendents a range of diameters from ¼ to 7/8 of an inch, but Opsahl notes over the last decade or so superintendents have trended toward larger tines. “There’s been a shift … since 2008 or so,” he says. “There’s been a gradual shift toward a larger diameter, more toward ¾ of an inch.
“Certainly, we still have people who are saying ‘I’m not going to change what I’m doing for my aeration treatment. I’m still buying my ?-inch tines and I’m going to continue to do that.’ (But) you’re seeing a gradual shift toward a larger tine.”
Hartwiger has witnessed the same trend and adds by punching more holes and decreasing the space between them superintendents can theoretically get the job done in half the time. “I’d say that people prefer to punch more holes in their greens less frequently,” he says. “Therefore, they would have closer-spaced holes so they can put more holes in the green when they do it, rather than (spread it out) over two dates.”
Aerating regularly is like visiting the dentist when needed, Hartwiger says. “If you’ve got to get two teeth pulled, do you want to spread that out over two different dates?” he says, “Or do you want to just go and get it over with that one time?”
To minimize the impact, some superintendents have gone to using smaller tines, with smaller intervals between them, on their turf. For example, a Northeast course that aerates in the spring and early fall with ½-inch tines might switch to slightly smaller tines but with tighter spacing; the tines might be set 1½ inches apart instead of 2 inches. In some instances, the facility might aerate a third time during the season.
“The net result is about the same amount of surface area disrupted in one treatment,” Moeller says, “but hopefully with a shorter recovery time because you’re using smaller tines.”
The challenge is getting sand into those smaller tines. It’s difficult to fill the holes punched by smaller tines. “So then you’re going through the whole process of aerating and cleaning up the cores but if you’re not able to able to fill those holes with sand you’re not maximizing that aeration treatment,” Moeller says. “You’re not seeing as much of the benefits of aeration.”
This approach is not without risks, particularly if a facility is extending aeration intervals, Moeller says. “A lot of (smaller tines) can have short-term advantages in terms of less revenue loss,” he says. “But if you’re not aerating as much as your soil and your putting greens require, at some point down the road there are likely going to be problems.” He adds putting green damage or turf decline develops because of too much organic matter or not enough drainage in the putting greens.
Some superintendents utilize needle tining, or solid-tine aeration, on high-stress areas to enhance the turf’s health. This method involves using tines with a diameter of perhaps ¼ inch or smaller to allow additional air to circulate through the root zone with minimal impact on the turf from a playability point of view.
Needle tining has proven particularly effective in areas prone to prolonged drought, or in warm, humid climates. As a result, the practice is becoming more prevalent throughout the industry, Moeller says. The benefits are short-lived, he says, lasting just a couple weeks. However, you get critical air flow in and out of the soil profile.
There is no one-size-fits-all model when it comes to aeration methods, Moeller says. Some courses, particularly daily-fee facilities, are reluctant to aerate at all, citing the cost in man hours, or lost revenue while the course is shut down or even afterward, because many golfers shy away from playing a course with recently aerated greens.
It comes down to weighing that risk at each facility, Moeller says. Summers with more extremes in heat and moisture are when you see the effects of deferred maintenance programs, like aeration.
“If the summers were mild and we didn’t have stress, we could maintain our golf courses probably with a little bit less input,” Moeller says. “But we’re preparing our courses for ‘What if we get really bad weather?’ Aeration is a great program that helps balance everything out and improves the health of the greens.”