What you should know about goosegrass

May 14, 2019 -  By
0 Comments
Goosegrass (Photo: Matt Elmore)

Photo: Matt Elmore

A weed by any other name would be as bothersome: This grass has the nickname “crowfootgrass” in some regions because its seedheads can resemble a crow’s feet. The center of the plant is whitish in color, so it’s also sometimes referred to as “silver crabgrass.” No matter what name it goes by, it’s never great to find it in a lawn.

It lays low: Despite this weed’s close resemblance to crabgrass, it doesn’t grow as tall. It often has a prostrate or rosette growth habit. In the summer, it could be as wide as 6-8 inches. It also may grow faster than the surrounding turfgrass.

It’s a later bloomer: This weed is a warm-season summer annual, and it germinates in soil temperatures that reach 60-65 degrees F at a 4-inch depth. It is generally thought to emerge about three to four weeks after crabgrass.

It likes traffic (unlike the rest of us): This weed is often associated with highly compacted areas. Look for it in areas where high traffic has caused turfgrass to thin, especially in the months of June, July and August, when this weed is most prolific. These are the areas where this weed is the most competitive, since crabgrass is not as dominant in a compacted soil environment.

It seeks out warmth: This weed can be found throughout the majority of the U.S., but in cooler climates, it tends to be located near areas that heat up quickly during the summer months. Look for it near sidewalks and roadsides.

It has traveled: This weed is native to Europe and Asia. Based on the comparisons to crabgrass, you may have guessed that the weed in question here is goosegrass.

Despite its similarities to crabgrass, because it emerges later in the season, it cannot be treated the same way.

One way to control the presence of goosegrass is turfgrass competition, which is true of all weeds, says Matt Elmore, Ph.D., assistant extension specialist in weed science at Rutgers. To encourage the growth of desirable turfgrass, it’s important to reduce compaction. Aerating high-traffic areas once per year loosens soil and allows for healthy turf growth.

It’s also important to properly time the application of a preemergent herbicide. If goosegrass and crabgrass are found at the same site, a sequential application of a preemergent is likely the best option for control, since goosegrass germinates later in the season than crabgrass.

Elmore cautions lawn care operators to recognize goosegrass’ resistance to preemergent herbicides.

“One of the things that has happened in the South is that is has shown a propensity to develop resistance,” he says. “That’s unique compared to crabgrass, and you need to be cognizant of the preemergent herbicide rotation … You have to follow up with a postemergent to prevent resistance development.”

As far as postemergent herbicides go, Elmore recommends using products that contain topramezone, dithiopyr, fenozaprop-p ethyl or carfentrazone. Other active ingredients that fight goosegrass include mesotrione and quinclorac.

For postemergent treatment, Elmore recommends scouting the turfgrass and knowing where you have a history of the weed to make sure you apply the herbicide while the plants are still small. Once the plants are in the late-tiller stage, you need more product, he adds.

Sources: Matt Elmore, Ph.D., assistant extension specialist in weed science, Rutgers, The State University of New Jersey; PBI-Gordon

This article is tagged with and posted in 0519, Current Issue, Turf+Ornamental Care
Clara Richter

About the Author:

Post a Comment