What’s the best way to control weeds on your sports field? Jared Hoyle, a turfgrass professor from Kansas State University, offered up the answer at the beginning of his seminar, “Advanced Weed Control for Athletic Turf,” with a simple but sensible answer.
“Managing turf properly is the best control you can have against weeds,” stated Hoyle, who spoke at the 2014 Sports Turf Managers Association’s Conference and Exhibition in January.
But, as Hoyle stressed, you must do your due diligence. For starters, a field’s turf needs to contain the appropriate turfgrass variety to be properly managed. If the field is in the shade, it should contain a shade-tolerant variety, Hoyle said, citing the National Turfgrass Evaluation Program as an excellent source to find the right variety.
Proper irrigation is vital to achieving properly managed turf, Hoyle added.
“If you irrigate too much, you can stimulate weed germination and do more harm than good,” he added, suggesting a strategy of deep and infrequent irrigation to stimulate root growth.
Hoyle said proper mowing provides excellent weed control, but he noted that each turf species has its own range of tolerance. For instance, if turf is mowed below that range of tolerance, it can thin and be overtaken by weeds. If it’s mowed above range, and leaf blades are left to hold more moisture, the turf is more susceptible to disease and may appear puffy.
For the best results, Hoyle suggested field managers mow every five to seven days, and avoid midday mowing when heat stress can occur.
Hoyle noted there’s good news and bad news with bagging clippings. The good news is bagging them may reduce weed seeds; the bad news is that it also robs turf of nitrogen, so field managers who bag clippings should fertilize 25 percent more annually.
Fertilization also plays an important role in properly managed turf, with rates varying depending on environmental conditions and soil type. When fertilization is right, the turf experiences more root growth than top growth, Hoyle noted.
Cultural practices, such as thatch control and aerification, are also important, he added.