According to the dictionary, “dog days” is the period between early July and early September when the hot, sultry weather of summer usually occurs in the northern hemisphere. It’s also the time that your soil is warmer than the air temperature for much of the daylight hours and all of the night.
For cool-season grasses, patience is required; you do not want to “push” the grass. This is not the time of year to stress out your turf—the grass has very little resiliency and will not tolerate much abuse or recover quickly.
“We do our fair share of cultural practices leading into the summer to try and prepare it for what is ahead,” said Blaise Restifo, Director of Sports Turf for Stanford University Athletics.
You may already have an aggressive plan for thatch management or a plan for applying products, but here are four more ways you can get your turf ready for the “dog days” of summer.
Take Advantage of the Transition Zone
If you’re located in the area of the United States known as the transition zone, you’ve probably experienced the struggle of growing turf in a mixed climate. However, there are specific things you can do to take advantage of it by planning ahead.
“Being in the transition zone, we look forward to the hot, dog days of summer,” said Casey Carrick, Director of Athletic Grounds and Turf Management for the University of North Carolina in Chapel Hill. “Right now, we are starting to push our bermuda a little harder, while still maintaining our ryegrass.” Carrick added, “It’s a challenge to do both, but we know the earlier we can get the bermuda running, the better off we will be during the summer.”
Carrick said they also pull cores, verti-cut and lower the mowing heights to help the transition. “Once our seasons are over, we will spray out the ryegrass, and it’s full speed ahead for the bermuda.”
Matt Parrott, Director of Field and Facility Operations for the Charlotte Knights, said, “In Charlotte, we are fortunate to grow bermuda grass that is generally pretty resilient to summer stress in terms of heat, drought tolerance and wear tolerance.” Parrott also recommends a balanced fertility plan based on regular soil testing.
“Enhanced efficiency fertilizers, a foliar fertilization program, along with products that focus on overall soil health characteristics, are fundamental in our fertility program,” Parrott said.
Develop an Irrigation Strategy
“As it gets warmer,” Carrick said, “We start to run our irrigation cycles for a longer amount of time. We try to irrigate as little as we can while still having a healthy plant. We use soil sensors to monitor our soil moisture and usually base our irrigation schedule off of that.”
Carrick also stressed the importance of establishing wilting percentages. “When we do get hot spots,” he said, “We hand water, and we often use wetting agents on the entire field to help distribute water.”
“Our irrigation management practices are dictated by the fact that our rootzone is constructed from 100% USGA sand,” said Parrott. “From our schedule, we try to achieve deep and infrequent watering.”
“Having a sand-based profile,” Parrot added, “We don’t have the ability to hold water in the rootzone profile as we may with other soil structures. To help offset this, we utilize a couple of different wetting agent products throughout the growing season depending on demand. In the event we do develop hot spots, we treat them on an individual basis with both aeration, the use of wetting agents and hand watering.”
Restifo said, “We have a pretty sound irrigation plan that involves deep and infrequent watering. With very limited rain, this fits our operation best and provides the best moisture for our fields.”
Restifo also said the use of wetting agents has been a big help. “We start those in April to get a base as we move toward the warmer, drier months. As for hot spots, we syringe areas during the day and also have a few crew members in the morning watering hot spots to stay ahead of them.”
Establish an Aeration Schedule
“I am a huge advocate of routine aeration,” Parrot said, because it allows “for not only increased lateral water movement, but also gas exchange in the soil profile along with routine light topdressing to protect the crown of the plant.”
“Many times,” Parrott said, “In-season aeration takes place with solid tines depending on our team’s schedule and outside event load. We typically try to set aside time for at least two core aerations during our baseball season and a total of three to four core aerations throughout the course of a calendar year, while fitting in solid-tine aeration at every possible opportunity.”
Come Up with a Deficit Irrigation Plan
Deficit irrigation assures that thunderstorms will be the reason for excess wetness, not the irrigation schedule. This irrigation plan should encourage the turf to dry without over-drying between irrigations or thunderstorms.
If excess drying does occur, it probably will start in small, highly localized areas, which can be effectively managed with well-timed syringing to re-hydrate dry leaves and prevent crispy thatch during the heat of the day.