Steve Dewey, Utah State University, Bugwood.org
Henbit is a winter annual, and not surprisingly, gets its name from the fact that chickens enjoy eating it. It looks like and is often confused with deadnettle; however, it has pink to purple flowers and can grow up to 10 inches tall. It prefers thin lawns that are rich in nutrients and is hard to eliminate once it takes root.
It's best to apply a pre-emergent herbicide in late summer or early fall to prevent henbit from germinating. If it's already established in the turf, a postemergent herbicide with triclopyr will help to knock it down. Try to use a three- or four-way herbicide with a combination of fluroxypyr, triclopyr and clopyralid for maximum weed control.