Superintendent Magazine - September, 2011
FEATURES
The 'Hole' Enchilada
Experts share tips on putting green aeration.By Larry AylwardIt's early August, and the temperature is hovering around 100 degrees Fahrenheit in St. Louis, where Joe Wachter is the golf course superintendent of Glen Echo Country Club. August is starting off where July left off - and it was one of the hottest Julys in the city's history.
The greens on the golf course at the Rock Creek Cattle Co. are awakened in the spring with a core aeration.
PHOTO: COURTESY OF ROCK CREEK CATTLE CO.The conversation with Wachter turns from the weather to aeration, which has everything to do with the hot weather and more. Ask any superintendent about aeration, and he or she will tell you that each course will have its own distinct program, because each course has its own microclimate. Throw in different soil and grass types, water quality issues, number of rounds, etc., and a course's aeration program gets even more defined.
Consider this a refresher course on aeration. We checked in with a few superintendents as well as Bob Carrow, Ph.D., professor of turfgrass management at the University of Georgia, to get their aeration tips. Some will sound familiar, and some might make you think about doing things a little different.
Getting an early start
The early bird gets ... happy golfers.
Wachter core aerates his course's putting greens, which average about 30 percent Poa annua and 70 percent Crenshaw bentgrass, in the spring with .5-inch hollow tines. He prefers to get out in the early spring to get the all-important but intensive task done ahead of time.
"The best time to do it is the middle of April," Wachter says. "But I try to do it before the first of April just to get it done and out of the way."
That way, the greens are healed up and ready for opening day, Wachter says. And then he doesn't have to carry out another golfer-disruptive task until the following October.
"We want to aerate as early as possible so we don't disrupt the players," Wachter says.
Wachter's initial core aeration usually lasts until May, when he implements a monthly needle-tine aeration program with a Verti-Drain. Wachter uses .25-inch solid tines and aims to complete the task on the first of each month through September.
Also during the summer, Wachter hires a contractor to aerate the greens with a Hydroject. The HydroJect, manufactured by The Toro Company, aerates the greens with "water jets." These jets are pulses of high-velocity water, released at regular intervals.
Wachter prefers to bring in the HydroJect sometime in July, "during the middle of the heat," he says. The process is not very disruptive to the greens.
Wachter waits until the end of October to perform the final aeration of the season - a solid tining of about 8 to 10 inches. Those holes are filled with sand.
For the year, the Glen Echo greens receive about six aerations/ventings.
Core aeration is important for many reasons. It's also the best time you can put down the most sand and work it in to dilute organic matter, says Bob Carrow.
PHOTO BY: LARRY AYLWARD"If the weather doesn't cooperate, we might end up missing a needle tine," Wachter says. "But usually we get at least three needle tines, one HydroJect and two deep-tine or core aerations."
Wachter, who has been a superintendent since 1993, has changed his program over the years, keeping up to date with new technology, such as needle tining. He likes that needle tines can punch holes about 1.5 inches apart. That way, the greens can be dried in the root zone if they are too wet, or they can be watered in the root zone when they're too dry.
Wachter realizes that many of his peers prefer to core aerate greens in the fall, but he prefers not to because the created holes encourage Poa annua growth, and fall is ideal for Poa annua germination in the St. Louis area.
"I also don't like to disrupt the greens," Wachter says. "It's still too hot to aerate, and I don't like to tear them up. Besides, they're usually trying to recover from some type of damage anyway."
Wachter prefers deep tining the greens in the fall.
"I just want to get a deep base so they will drain in the winter and grow strong roots late into the fall," he says.
Wachter realizes he wouldn't have a job if it weren't for golfers. So he's all about pleasing them, which means working around them as far as aeration scheduling.
"I've tried to move it to times that are the least disruptive for golfers," he says. "We're here to make golfers happy ... and keep them happy."
On occasion, a certain green might require an extra needle tine or solid tine aeration. That would be Glen Echo's 11th green, which is flat and doesn't drain well.
"Waking up" the greens
Isaac Farabaugh, superintendent of the golf course at Rock Creek Cattle Co. in Deer Lodge, Mont., faces a challenging aeration schedule because the golf season is so short, about three and a half months, in his area of the country.
"Sometimes the ground freezes early, and we end up not getting it all done in the fall," Farabaugh says.
Rock Creek features a links-style, Tom Doak design. Being a newer course with only 3,000 rounds a year, Farabaugh has very few thatch and compaction problems on the greens. He core aerates the greens once in the spring and again in late August, and supplements with a PlanetAir machine every two weeks. The PlanetAir shatters soil with a kick-back action that reduces soil compaction.
"We also solid tine once in the spring, once in the midseason and once in the fall if we can get it done before the ground freezes on the tees and fairways," Farabaugh says.
It's a program different from most because of the short season. Still, aeration is vital. Farabaugh's initial core aeration plays a key role in "waking up" the greens in the spring when soil temperatures are still cold in order to get the golf season rolling. He also uses twice the normal amount of nitrogen in the spring to get the turf going out of dormancy.
Carrow: Not just cultivation
The University of Georgia's Carrow is a proponent of core aeration, but not just to create large holes. It's all about the topdressing, Carrow says.
"It's not just the cultivation process that's so important," he adds. "It's also because that's the time you can put down the most sand and work it in to dilute organic matter. It's just a better way of controlling organic matter accumulation."
A core aeration's effectiveness will typically last four to six weeks, in terms of sufficient water and oxygen infiltration, Carrow says. Then it's time to implement a venting program, such as tining.
Slitting, another form of aeration, is also less disruptive, even more so than deep tining. But slits don't stay open for long, Carrow says. "You're better off to do a .25-inch solid tine," he adds.
In the South, where the winter is short, Carrow says superintendents should solid tine greens as soon as the weather allows it, like in mid- to late March. This will relieve oxygen stress and poor infiltration, and promote maximum root growth later.
"The best time to core aerate greens on warm-season grass is when it's warm enough to achieve rapid recovery," Carrow says. That would be May or even into June.
Superintendents who oversee courses that receive heavy winter play can't core aerate during those months because recovery doesn't came fast enough in the cooler weather. Carrow suggests two or three tines to keep the greens open just enough to where they aren't disruptive.