By Stephanie R. Butcher, Coweta County Extension Service
QUESTION: How can I get rid of a weed in my lawn? It has a purple flower, and it is taking over.
AGENT: Henbit is a winter annual weed that germinated this past fall and early winter. On warm winter days, it takes advantage of the sunshine and grows well in areas where soil moisture is good and turfgrass is thin.
This weed is often confused with purple deadnettle, but the same herbicide will control both weeds.
Henbit is nearing the end of its life cycle and will die back as the weather gets warmer in late spring and summer. The best time to treat for this weed is in the fall when you can apply a preemergent prior to its germination.
I have spoken with several homeowners already this year whose lawns have been taken over by henbit lately. You can apply a herbicide to control broadleaf weeds such as henbit, but if you don’t include a management strategy for improving your lawn along with a chemical control option, then you are going to wind up right back where you started this time next year.
The best way to control henbit in lawns is to manage your turfgrass so that it is thick and lush, making it difficult for henbit to grow. Make sure that you soil test so that you can fertilize and lime as needed for a healthy soil. If your pH and fertilization are not adequate, then you can bet you’re going to deal with more weeds than you would otherwise.
Post emergent herbicides with 2,4-D listed as the active ingredient will control henbit. There are also 3-way products containing 2, 4-D that are available, and they will control a wider range of broadleaf weeds. No matter which product you choose, make sure that the herbicide you purchase is labeled for application on your particular type of turfgrass and always read and follow all label directions. Herbicides should be applied when weeds are small. As weeds reach maturity, they become harder to control.
Even if you choose to treat henbit with a post emergent herbicide, you should still soil test. Fertilize and lime your lawn based on the soil test recommendations and also consider applying a preemergent herbicide in early fall to help prevent these weeds next year.
Caution: Do not apply herbicides to lawns that are in spring transition, that is – when they are greening up. You also want to avoid applying herbicides when temperatures are above 90 degrees.
For more information on lawn management this spring, call the Coweta County Extension office at 770-254-2620 and ask for UGA publication, “Strategies to Control Winter Weeds” and “Soil Testing for Home Lawns”.
The University of Georgia College of Agricultural & Environmental Sciences is an equal opportunity, affirmative action organization.
Photo Credits to Michigan State University Cooperative and North Carolina State Extensions.