While no two winters are exactly the same, it is possible to take note from the season we’re in to have an idea what awaits when spring emerges. Superintendents and researchers can look at the short, wet fall and cold, snowy winter for historical perspective on upcoming challenges this spring.
Winter injury is most likely lurking under the snow and ice, says Jared A. Hoyle, assistant professor and extension turfgrass specialist at Kansas State University.
“This includes many different types of injury, including but not limited to: freezing injury, desiccation, freeze covering (ice) and traffic (wear),” Hoyle says. “Although, the general trend for the North Central United States was a wet fall and cold, snowy winter, here in Kansas we have had a dry, cold winter with a couple of days mixed in where the temperature got well above 60 degrees. When the temperatures get in the 60s or even in the 50s in the middle of a Kansas winter, everyone who has the ‘golf bug’ crawls out of their houses to go play some golf in the nice weather.
“Who knows, after that warm spell it might not get above 32 degrees for another 10 days,” he says. “During this time, the entire golf course is subjected to all sorts of traffic and injury from play. Golf carts are driving on frozen fairways, golfers are creating traffic patterns on the greens, and wet tee boxes are being ripped apart by the endless spike combinations that golf shoe manufactures are producing. But like all situations in managing golf courses, each golf course, putting green, tee box and fairway is unique. Therefore, it is hard to predict exactly what Mother Nature is going to give us this spring.”
With regard to spring aerification, Hoyle says preparation is the best strategy to follow.
“Start now and have all equipment ready to go and have all supplies ready,” he says. “Step two: Have a plan. When you think you have a plan, then think of how this may need to be adjusted if something should go wrong or if the weather does not cooperate with your aerification schedule.
“Step three: Have a backup plan,” Hoyle adds. “Planning is very important and can determine how your summer is going to go. There are two times a year when superintendents can push their turfgrass for a healthy growth; spring and fall. Growing a healthy turf in the spring will help with maintenance in the summer. If a turfgrass manager does not do due diligence to their turf in the spring, they will be playing catch-up all summer long.”
As drought conditions range from D0 (Abnormally Dry) to D4 (Exceptional Drought) across much of the West and Southwest, superintendents are going to be faced with the difficult decision on when to aerify or verticut their turf.
According to Patrick Gross, director of the USGA’s Green Section West Region, the decision on when or if to aerate isn’t necessarily related to the drought. Do not aerate or verticut a stressed plant.
His advice? First, make sure the turf is as healthy as possible. And pay close attention to the irrigation system so you’re not wasting water. There’s a long list of best management practices, such as using wetting agents or hand watering, so ensuring the turf is healthy is the priority.
Fortunately, aerating and verticutting are generally spring and fall activities, so the turf is less stressed than it is during the summer months.
While not all inclusive, Hoyle points to fertility and timing as keys to a successful spring aerifcation program.
“Always make sure the plant has the nutrients it needs to recover from aerificaiton injury,” he says. “A fertility application a couple weeks prior to aerificaiton can increase the speed of recovery. This gives your turf a jump-start prior to aerification.
“Timing your spring aerification can not only help with thatch reduction, compaction, improved drainage and provide a smoother putting surface, but it can also be timed to help prevent weed development,” Hoyle adds. “More specifically, annual bluegrass. Aerification in the spring can be timed prior to a spike in annual bluegrass germination and growth (late spring/early summer). Therefore, aerifying in the spring before the soil temperatures reach 55 degrees (0-2-inch soil depth) will encourage bentgrass growth while minimizing annual bluegrass encroachment.”
Kevin Frank is hopeful the conclusion of this winter doesn’t meet the level of the prior winter that produced ice cover on putting greens from Chicago to Toronto. While Frank, an associate professor and extension turf specialist at Michigan State University, has seen reports of thin ice sheets at various locations, reports seem to show the ice formed approximately the third week of January — or about three weeks later than ice forming the previous winter. His hope is a “normal” spring will result in this ice melting off before damage may occur to Poa greens.
As for Frank’s idea of a spring aerification strategy, that depends on what species you’re trying to manage - Poa or bent.
“If you have predominantly Poa annua greens, then the thought is to aerate following seed production,” he says. “During seed head production, the Poa is not producing many new roots, so once it’s over, this is the time to try and grow some roots before summer temperatures arrive.
“I think this is still the case if you’re suppressing seedheads with plant growth regulators, as typically you don’t get 100 percent seedhead suppression from PGRs,” Frank adds.
“If you’re trying to favor bentgrass, then the idea would be to aerate during the beginning of Poa seedhead formation,” he continued. “Poa is busy pushing seedheads, not roots, so bentgrass is at a competitive advantage during this time.”
The reality with either of these strategies can be affected by weather that could make optimal timing strategies difficult due to excessive soil moisture, Frank says.
As for verticutting, Frank doesn’t generally feel strategies should be affected by winter unless there is significant damage from the season. That damage may cause superintendents to consider verticutting to facilitate reestablishment and recovery, he says.
Because verticutting injures the turf, Hoyle says it is important to know why you are verticutting.
“Verticutting in the spring can help remove dead and dormant organic matter,” he says. “It can also help expose the turf crown to improve soil warming and promote green-up. When vericutting is part of your spring management plan, keep in mind your goals and objectives. Is your goal to recover from winter injury, plant new seeds, remove thatch, etc.? This can determine the aggressiveness of your verticutting practice and how you incorporate it into your plan.”
Regardless of the type of spring — cool vs. warm, dry vs. wet — Hoyle suggests superintendents go back to the basics and adjust their strategies accordingly.
“Superintendents may need to aerify/verticut earlier in the season than expected if the conditions are present and the same is true if spring comes later than expected,” he says. “With that being said, being prepared and having a plan is most important.”
Too late? Missed the window for preventative maintenance. Again, go back to the basics.
“Do what is needed to grow and maintain a healthy turfgrass stand,” Hoyle says. “Proper irrigation, weed control, mowing and fertility, we sometimes forget about when we are faced with a challenge. We tend to lean toward a ‘silver bullet’ when we are thrown a curveball. We want to apply one product or do that one ‘miracle’ management practice that can get us out of this hole because Mother Nature was not kind to us this past winter, but in reality we can get back on top by going back to the basics.”
Work with one another, Hoyle adds. Working with other superintendents and turfgrass managers by asking questions, finding out what worked for them and most of the time eliminating what didn’t work, can help everyone build new plans for the future.
“Keep detailed records,” he says. “Not only dates of when applications or management practices have been implemented, but also include weather data. We all know that each year is different: Spring can come early or late. Knowing what worked/didn’t work in the past when we have been faced with a challenge will also help in building future plans.”
It’s important to read the keys and give the turf what it’s asking for, Frank says.
“Depending on what Mother Nature delivers, I’ve always thought, ‘Don’t be afraid to get the water on,’ especially if it’s dry and warm, which we sometimes get coming right out of winter/snow melt,” he says. “Generally, if it looks like it needs help, don’t be afraid to give it some, whether that means water or some fertilizer.”
Rob Thomas is a Cleveland-based writer and frequent GCI contributor.