Images: Seed heads on mature johnsongrass plants (above; Missouri Dept of Conservation). Johnsongrass spreads through rhizomes (below).
Johnsongrass is a widespread weed throughout the US, with herbicide resistant populations in the midwest, south, and mid-Atlantic. Effective control involves targeting the seedlings before they have a chance to develop the rhizomes, which are quickly-spreading and more difficult to control.
- Group 1 (phenylpyrazolin, fops, dims)
- Group 2 (ALS)
- Group 3
- Group 9 (glyphosate)
Locations of resistant populations:
Arkansas, Mississippi, Nebraska, Tennessee, Texas, Virginia (Search by State to see which resistant populations are in each state)