Spurweed or lawn burweed |
Lawn burweed is a low-growing, freely branched winter annual having leaves similar in appearance to tiny carrot leaves. This weed usually germinates in the early fall months, and remains very small, and inconspicuous in the lawn over the winter. As temperatures warm in the spring, it grows rapidly, flowers, and forms seed with a small spur or spine in the leaf axil junction.
If you did not apply a preemergent herbicide this past fall to control winter annual weeds, and you had lawn burweed in your lawn last summer, then you most likely will have them again this year.
But there is something you can do now. The trick to eliminating the spiny sticker problem is to control the weed before the spur is formed. If you wait to control the weed after the spur is formed, you can kill the plant, but the spiny sticker will still be there waiting for unsuspecting bare feet or hands.
To control this weed in lawns, (that have not been over-seeded with a cool season grass) several herbicides are recommended. The ideal time to apply is from December to March, preferably on days with temperatures of 60 degrees F or warmer. The earlier in the season you apply the weed-killer, the easier this weed is to control.
The following homeowner-labeled herbicides will control this weed and numerous other winter weeds. Choose one of them and mix it at the recommended rate in one gallon of water and spray over a 1000 square feet area: Atrazine @ 1.5 ounces, Weed B Gone @ 3 ounces, Ferti-Lome Weed Free Zone @ 1.5 ounces, 2,4D @ 1.5 ounces, Bayer Advanced Southern Weed killer @ 2 ounces, Trimec @ 2 ounces, or Spectracide Weedstop 2 @ 2 ounces.
If the clumps have gotten large or the weather is too cool, two applications might be necessary. Wait 10 – 14 days after the first application to make the second one. Do not apply these herbicides around the drip-line of trees or in flowerbeds.
Timely application of one of these herbicides will eliminate or greatly reduce this ‘sticky’ problem. You can be better prepared next year if you apply a preemergent weed killer next October. Contact your local extension office for a copy of P1322 Establish and Manage Your Home Lawn that contains a list of preemergent herbicides to control this weed.