By Tom Smith
Many of us are enjoying the cooler weather after last summer's blazing heat, thinking of the holidays, hunting, almost anything but yard work. But there may be some lingering effects of the extended drought we have experienced. Bare spots may now show where lush grass once grew. These bare places offer an opening for weeds to enter, stealing nutrients from the grass and possibly causing other problems. And now is the best time to treat many cool-season weeds.
One such invader has been the source of several questions and phone calls every spring, but by then it is too late to stop it. A tiny plant with leaves similar to parsley has infiltrated many lawns and pastures, with little notice. With little notice, that is, until this weed, known as spurweed, carpet burweed, or lawn burweed, begins to mature in the spring and develops seed pods that have sharp, spiny stickers. These burrs make walking barefoot across the lawn painful, and also imbed themselves in the feet and hair of pets, which can then bring them indoors and transfer them into the carpet for their owners find with their own bare feet.
Despite its size, this tiny weed is difficult to control. The most common herbicide ingredient, 2,4-D, is not effective against this pest. Products containing simazine can be used in warm-season grasses as a pre-emergent herbicide if applied after October 1, but should not be applied to cool-season grasses.
Herbicides containing glyphosate, such as Roundup or Glyphos, can be used in winter-dormant bermudagrass, but will injure or kill plants that have begun to green up. Products containing a mixture of 2,4-D, MCPP and Dicamba, such as Trimec or Weed-B-Gone, have also proven effective, and can be used this time of year. For pastures, herbicides containing Dicamba such as Weedmaster, Cambamaster or Rangestar provide good results. Many herbicides will kill or damage St. Augustine and some other grasses, so read the label carefully for species of grass and target weeds. Speedzone herbicide is labeled for spurweed control in St. Augustine. For use in either lawns or pastures, care should be taken to avoid application where the herbicides can be absorbed by roots of desirable shrubs or trees.
As with all pesticides, read the label carefully for information on precautions, protective equipment, target sites, mixing directions, application rate, susceptible plants, directions for use and other information. Remember that the label is regarded as Federal Law, and problems arising from violations may be treated accordingly.
Finally, remember that the best thing you can do for your lawn or pasture is to provide the correct nutrition so it can remain healthy enough to prevent weeds from encroaching on its territory.
For more information, contact Tom Smith at the Pushmataha County OSU Extension Office located at 306 SW B Street in Antlers, or call (580)298-5563. Oklahoma State University, U. S. Department of Agriculture, State and Local governments cooperating. Oklahoma State University in compliance with Title VI and VII of the Civil Rights Act of 1964, Executive Order 11246 as amended, Title IX of the Education Amendments of 1972, Americans with Disabilities Act of 1990, and other federal and state laws and regulations, does not discriminate on the basis of race, color, national origin, gender, age, religion, disability, or status as a veteran in any of its policies, practices, or procedures.