The Goldilocks Syndrome faces superintendents every week as they strive to provide water for their turf. Irrigate too little and the bentgrass will die. Irrigate a bit too much and dollar spot will take over the tee boxes. Don’t even think about the impact of having way too much water!
But if you get it just right, Goldilocks will be happy as she does an extra hip waggle on her course’s immaculate bentgrass greens.
There will be problems in areas where there is poor percolation, where thatch has accumulated, or over a clay lens. All are welcome mats for disease. Too much water can be fatal. Water-enhanced problems like Pythium just love plants with wet leaves.
“If you control your inputs, you are in a better position to control the whole situation,” said Stephen Miles, CGCS at the Preserve Golf Club, Vancleave, Mississippi. “You do that by following the LAWS: light, air, water and soil.”
Prior to 2014, the Preserve was neglecting Miles’s LAWS. Clays were migrating into the sand-gravel interface and clogged the drainage. Some holes with trees shading the greens suffered from a lack of sunlight. “That connects back to moisture since those holes stay wetter longer. They are more prone to decline and disease and algae problems,” Miles says.
That situation changed with a recent renovation that included better drainage and the addition of quick- couplers to minimize the amount of overhead irrigation required.
One region where Mother Nature has made it impossible to control water this year is the Pacific Northwest. Following several dry years, the torrential rains in California and the Northwest have made national news.
“You can never have enough drainage in a year like this,” says Matt Grove, CGCS at Centennial Golf Club in Medford, Oregon. Located in the Rogue River Valley, the 18-hole daily fee course is blessed with low humidity in a normal season.
“We have wet winters and dry summers,” Grove said, and this year it was uber-wet. Even in a normal winter, however, evapotranspiration (ET) is low and offers little help.
The soils on the course are clayey so drainage is a challenge. “You can’t do a deep watering,” he says. “We irrigate based on ET every night and do some hand watering” of their 50-50 bentgrass-Poa greens. Fairways are a Poa-rye mix.
Keep it to a minimum
“We irrigate as little as possible, because as soon as I start to run the irrigation, two days later we’ll get a lot of rain,” Miles said ruefully. His solution is to use a soil moisture meter on every putting surface. “We only water a green if the moisture meter calls for it, or if we need to water in an amendment or sand,” he said. Given the choice, he always prefers watering by hand.
Using a meter is one key to successful management, according to Jay McCurdy, assistant extension professor of turfgrass science at Mississippi State University. When we spoke, McCurdy was just returning from a session with superintendents who were discussing how often and how deep they should water. Although McCurdy says 20 percent volumetric water in a green is the sweet spot, he knows that figure can vary based on the soil type, organic matter and sand content of a green.
“Twenty percent volumetric water makes sense in a loam or silt-loam green, but not in a sandy soil,” McCurdy said. No matter the soil type, he recommends the use of a probe or moisture meter to determine volumetric water content.
Miles agrees that it is tough to make overly broad assumptions because soil and drainage conditions differ from place to place – even on his wall-to-wall Tifway 419 course with TifEagle greens.
Mother Nature is not the sole cause of our difficulties. Jared Hoyle, assistant professor and extension turfgrass specialist at Kansas State University, Manhattan, Kansas, more often sees problems caused by little things like a weeping irrigation head that saturates an area and opens the door to weed infestations. Problem weeds like sedges and knotweed just love extra water and a leaky irrigation coupling will provide that exact environment.
Weeds are a bigger concern than disease at Centennial Golf Club, where its 7,309 yards of playable area are surrounded by several hundred acres of natural grass. While there might or might not be snow mold early in the season, Grove said they have all sorts of problems with weeds. “We’re like any other golf course – you have to stay on top of it,” he said.
By late February, they already have started their preemergence program outside the playing area and continue it on the rest of the course. This year’s exceptionally wet winter probably will not make the superintendent’s job any easier.
“I see more weed issues with too much water,” Hoyle said, adding that most superintendents stay on top of recommended irrigation practices, if for no other reason than to be environmentally responsible stewards of the water resources in their area.
Where issues tend to arise is when a course follows a regimen of light, frequent watering. Too little watering means that the water stays in the top profile of the soil and does not make it down to the turf’s root zone. However, that top quarter-inch or so is where weed seeds thrive. The result: Weed seeds get the water they need while the grass roots get parched. Water needs to be sufficient to get below the weed germination profile and into the area where it does the turf roots some good.
“Deep, infrequent watering is what the turf needs,” Hoyle said. This is especially true in the summer when water management is most important. “Most superintendents are doing things right.”
McCurdy agreed but sees areas for improvement. “We are able to irrigate greens and surrounds, so we do,” he said, although this can lead to continual flushes of crabgrass, goosegrass and Kyllinga throughout the season.
The Preserve has the usual challenges with brown patch, dollar spot and fairy ring. “We are on a prevention program,” Miles said. He knows that organic matter retains water and that removing thatch removes a sponge for that water. He constantly works to keep ahead of those challenges.
Where it is wet, brown patch always will show up. Shaded places retain moisture so drainage is a key to ensuring that soils are not prone to such diseases.
“I’d like to think cultural practices will help,” McCurdy said. One answer might be to have cleaner surrounds in the greens areas, which means using a preemergence herbicide on the surrounds in addition to other areas. McCurdy recommends using wetting agents to maintain acceptable water content.
Scalping a green is a recipe for disaster. A wet, open canopy is an invitation to algae and disease. Bring either or both onto a green and goosegrass is certain to fill in the open spaces.
Short of re-contouring greens, there is little that can be done about confluence areas where water flows from several areas into a single spot, leaving a puddly region to manage. Areas that prone to standing water are going to cause headaches.
The Preserve, a Silver Audubon International Signature Sanctuary, has a somewhat different water challenge: Its water is high in sodium. In fact, the only cation in the water is sodium. That means Miles is spared the problem of flush watering to remove salts, but he has had to spend a good amount of time figuring out how to manage and minimize the sodium situation.
Whenever he is in doubt, Miles returns to his four basic LAWS, which help him ensure The Preserve is in Goldilocks’s sweet spot: just right.
It is a constant struggle. “As soon as it stops raining, someone is going to be teeing off,” Grove said. One other solution is “cart paths only” to minimize the impact on the turf. Coupled with good practices, even the wettest season can be made manageable.