Henbit (Lamium Amplexicaule)
What does it look like?: Henbit is in the mint family and has the requisite square stem. Although fairly attractive, it can quickly become invasive. It prefers good soil and often appears when a lawn is thin and in the process of being established. The leaves are opposite each other, toothed, and the lower leaves are larger, with a stalk. Whorled, trumpet-shaped flowers of pink to purple, form in spring in the upper leaves.
What causes it?: Sparse turf. Spreads by seed.
When does it show up?: Early spring.
Best treatment plan: Seeds germinate in the fall, so a pre-emergent herbicide in the fall is the best bet to prevent next spring’s crop. In the spring, use a post-emergent for any survivors. Hand-pulling works for small infestations. Call a professional for a free quote.
How long will it take to get rid of it?: Treatment in the fall should prevent growing in the spring. But once emerged, proper treatment can quickly eradicate those.