Written by: Blake Edwards, Jason Bond and Tom Eubank
Scientific name: Lamium amplexicaule L.
Synonyms: Dead-nettle, henbit dead-nettle
Henbit is an erect or spreading winter annual with opposite leaves that are triangular to circular with rounded tooth-like margins. Cotyledons are oval and have no hairs. Stems have numerous ascending branches, are nearly square, and root at lower nodes. Flowers are typically pink to purple in color; however, some populations, albeit rare, will have white flowers (see photo). Henbit can often be confused with purple deadnettle (Lamium purpureum), which is sometimes called red henbit. Both of these weeds have square stems, as do most species in the mint family, and share the same pinkish-purple flowers. However, the leaves of purple deadnettle are more deeply serrated as opposed to the lobed shape of henbit, and leaves are also pointed on purple deadnettle. Leaves of purple deadnettle are reddish-purple in the upper canopy in the mature stage.
Henbit is native to Europe and Asia but can be found throughout the United States. It is common in crop fields, roadsides, pastures, and lawns throughout Mississippi. This weed usually emerges in early-fall and persists through late spring. Henbit is problematic in most spring-seeded crops such as cotton, corn, rice and soybean. Research has shown that henbit is an overwintering host of both twelve-spotted spider mites and soybean cyst nematodes. Henbit can be controlled in the fall with residual herbicides that minimize emergence through the winter. Spring-emerged henbit can be relatively difficult to control, depending on herbicide selection and growth stage of the weed. Common spring burndown herbicides such as glyphosate are not as effective on mature henbit. In these situations, a phenoxy herbicide such as 2, 4-D or dicamba, depending on the crop to be planted, should be added to glyphosate or paraquat.
Bryson, C.T. and M.S. DeFelice. 2009. Weeds of the South. Athens, GA: University of Georgia Press. pp. 218