If you look close, between the blades of grass in your lawn, you might find a very bad weed – lawn burweed and its spiny fruit. This low-growing annual weed pops up in the lawn each winter and by late spring it develops small fruit with very sharp spines. You really don’t notice this weed until you actually step on it. Ouch!
A fun spring day playing or walking barefoot in the yard can quickly turn sour. Since lawn burweed is bad news, especially for the young feet of children, homeowners need to do whatever is necessary to get rid of it.
The best strategy to control lawn burweed is to apply a pre-emergence herbicide, such as atrazine or isoxaben in late September to early October before the winter weeds germinate. This method will kill it upon sprouting and basically keep in from showing up in the yard.
When lawn burweed is a very small plant, it is much easier to control in November through February. During this time it has not yet to develop the spine-tipped burs. Spray the lawn with post-emergence herbicide containing the active ingredients of three broadleaf weed killers: 2,4-D, dicamba, and mecoprop (MCPP). Many brands of broadleaf herbicides on the shelf contain these ingredients. Using the herbicide 2-4-D alone may not be quite as effective so the three in one is preferred. Keep in mind that broadleaf herbicides are not effective unless applied when the temperature is above 68 °F. The window of opportunity can be very limited during the winter season. Again, another reason to use pre-emergence herbicides in the fall.
Unfortunately, most people do not notice a lawn burweed problem until spring. But waiting until spring is too late. If you wait to control lawn burweed in April and May, the spines have already formed by this time and it will remain after the weed withers and dies. This is when people happen to step on the stickers. Because lawn burweed is a winter annual, it will begin to die in late spring as air temperatures reach 90 °F. Once the weed has reached a more mature state, multiple herbicide applications may be necessary which increases the potential for turfgrass injury. Mowing the area at a very low height and bagging the seeds might offer some relief.
Some severe situations may call for killing the entire area, including the turfgrass, with a non-selective herbicide, such as glyphosate just to get rid of lawn burweed for good. Of course, one will have to replant grass or lay new sod but by this way there would be no more lawn burweed!
Dead or alive, lawn burweed poses a painful problem. The only solution to this is early identification and control. Remember lawn burweed is an annual and will come back from seeds that develop each spring. Take action and so those little bare feet and run wild without any dangers.
by Shane Harris, County Extension Coordinator, Tallapoosa County