Get ahead of weeds this fall.
With the stresses of summer largely in the rearview mirror, lawn care operators are turning an eye to fall weeds. Here’s the latest news on nutsedge and kyllinga.
In the Mid-Atlantic, it’s hard to predict which weeds will pose problems this fall, says Elliott L. Dowling, agronomist for the USGA Mid-Atlantic Green Section.
However, purple and yellow nutsedge and kyllingagrass are challenging, he says. Careful application is required on cool-season grasses, he cautions, especially during the summer heat.
“Many defer treatments until the weather breaks in the late summer or early fall,” Dowling says. “But populations expand throughout the summer. These weeds are perennial, so they must be controlled or populations will return and increase each year.”
Dowling urges lawn care operators to begin their post-emergent applications for sedges and kyllinga as soon as possible.
Goosegrass and crabgrass populations also may pose a problem for the Mid-Atlantic this fall, Dowling says.
“Where Bermudagrass is the primary turf, pre-emergence herbicide applications were delayed or skipped because of fears of winterkill after the cold winter,” Dowling explains. “They wanted the Bermudagrass to have every opportunity to recover and didn’t want to slow recovery with pre-emergence herbicides.”
The result, he says, is crabgrass and goosegrass populations that must be controlled post-emergently.
If post-emergent treatments are not performed on time –and Dowling says they should begin soon – lawn care operators in the region can expect to see higher outbreaks of crabgrass and goosegrass this fall. Post-emergent applications definitely will be required, Dowling says, and “products such as quinclorac, fenoxaprop-ethyl and sulfonyl ureas can be used, depending on the species of desirable grasses present.”
But before technicians apply anything, he cautions, they should check product labels for rates, timing and potential interactions with weather conditions.
A lawn care operator’s battle against weeds is perennial. But with wise judgment, effective cultural practices and attention to labels, they can hold their own.
Michigan State University research assistant Aaron D. Hathaway urges green industry professionals to communicate and keep up with research. “Winters like last winter will prompt a lot of research on what we can do to avoid that winterkill,” he says. “Often it’s the new things that superintendents try that prompt research. Often research is driven by their creativity.”