A Common Spring Pest: Burweed

Picture this: a beautiful spring afternoon stroll through a lucious, green lawn. Ironically, although this is characteristic of spring, the season also brings the pesky lawn burweed, sure to antagonize your leisure. According to Clemson University’s Extension Office, “lawn burweed (Soliva sessilis) is a winter annual that germinates throughout thin turf in the fall months as temperatures cool.” During this germination period, the weed is inconspicuous. But as temperatures steadily increase, the weed grows rapidly and spine-tipped burrs form in the leaf axils. Mr. Mike Randall from BWI describes the weed stating, “Lawn burweed has a ‘sticker’ like other weeds and is commonly mistaken for sand spur or pin turbine.”

“Soliva sessilis plant7 DC” by Macleay Grass Man

“soliva-sessilis-5” by Friends of Chiltern Mt Pilot National Park

If you fertilize and lime according to soil test results, and mow appropriately, you will maintain a healthy, dense lawn. These blades will compete with weeds for light, water, and nutrients, impeding burweed growth. 

Another healthy deterrent is to apply post-emergent herbicide during the winter months. This will kill off the weeds before they have time to form the burrs. Mr. Randall recommends that you always treat your burweed in the fall. “It’s a winter weed and is best controlled with pre-emergent in early fall as a preventative. Post-emergent herbicides, like weed free zone, can be used to control it.” It is recommended that you apply post-emergents between February and March. Mr. Randall concedes that if you miss the fall deadline it is never too late to apply pre-emergent to prevent seeds from growing into problematic weeds. 

The weed will begin to die in late Spring, as temperatures reach 90 degrees Fahrenheit.