What Is this purple flowered weed in my lawn? 03-03-08

A prominent weed displaying reddish-purple flowers in many home lawns now is most likely henbit (Lamium amplexicaule L.). Henbit is a sparsely-hairy winter annual having somewhat rounded opposite leaves with bluntly toothed margins. The leaves and flowers are arranged in whorls on tender, four-sided stems that are greenish to purple in color. Individual plants can become fairly large and become quite an eyesore in a dormant lawn even though the tiny purple flowers show a hint of spring.

Since this is one of many winter annuals that invade our lawns, the best control is applying a pre-emergent herbicide near Labor Day to prevent their establishment. However, once they are established post-emerge herbicides or mechanical removal are your options. If henbit is the only winter annual found in your lawn, mowing alone can be quite effective as it will prevent the plants from expanding and producing the purple flowers. This weed is also one of the first to start dying out in the spring, so hopefully, it will not be around much longer.

If you prefer the herbicide option Extension publication #1532 provides a list of several good post- emergent herbicide choices (atrazine, 2,4-D, dicamba, metsulfuron, chlorsulfuron, etc.) that will control this weed along with most other winter annual weed species.

Published March 3, 2008

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. [email protected]