Controling lawn burweed with herbicides
Wednesday, January 23, 2013 12:00 AM
Lawn burweed is a winter annual weed that becomes that nobody calls me about until spring when they step on its sticky burs. They want to know how to control it. They are not always happy when I tell them to spray . . . next fall.
Burweed seeds germinate in fall. It is a low-growing weed, pale green, with leaves somewhat resembling a miniature version of parsley. The plant remains small and inconspicuous during the winter. When temperatures warm in spring, this innocent-looking and often unnoticed weed begins to grow rapidly.
Spine-tipped burs form in its leaf axils. When these sharp, spiny burs dry and get hard, they hurt people running around barefoot on a nice early spring day. This weed can make a lawn area completely useless until it dies away and decomposes in late spring or early summer. Individual plants can form a mat spreading to a foot or more in diameter.
Burweed can easily be controlled by applying a pre-emergent weed killer in the fall or with post-emergent weed killers applied during the winter months before the spiny burs become a problem. Now is the time to apply the post-emergent weed killers, but wait until your lawn dries out because you can damage a lawn as wet as it is now.
Several herbicides that can be used for lawn burweed control in home lawns. Atrazine may be used in centipedegrass and St. Augustinegrass. Atrazine applied in November will also have post-emergence activity against newly sprouted lawn burweed seedlings and also will have pre-emergence activity against those that have not yet germinated during the fall.
Examples of products containing atrazine for home lawns are Southern Ag Atrazine Weed Killer, Hi-Yield Atrazine Weed Killer, Image for St. Augustine grass and Centipede grass with Atrazine and Spectracide
Weed Stop for Lawns Concentrate for St. Augustine and Centipede Lawns is the herbicide of choice for this time of the year. January, February, and early March are good times to apply a post-emergent herbicide for the control of burweed if you failed to apply a pre-emergent material or have escaped seedlings. A three-way combination herbicide may be used on Bermuda grass, Zoysiagrass, Centipedgrass, St. Augustinegrass and Tall Fescue. The active ingredients of a three-way herbicide often include the following broadleaf weed killers: 2,4-D, dicamba, and mecoprop (MCPP).
Examples of a three-way herbicide are Ferti-lome Weed-Out Lawn Weed Killer with Trimec, Bayer Advanced Southern Weed Killer for Lawns, Spectracide Weed Stop Weed Killer for Lawns, Southern Ag Lawn Weed Killer with Trimec, and many others. The key factor to effectively controlling lawn burweed is to apply an appropriate herbicide during the fall or late winter months. Always follow label instructions and precautions.
For more information on this and other lawn questions, call 601-656-4602 or visit the Neshoba County Extension Service office in the Neshoba County Coliseum and ask for publication #1322, "Establish and Manage Your Home Lawn."