Controlling Dallisgrass in St. Augustine: Spot Treatment Strategy

Dallisgrass (often misidentified as crabgrass or Johnson grass) has tall stems with sticky black seed heads. No selective herbicide distinguishes it from St. Augustine—both are warm-season grasses.

Use a wick applicator (Rittenhouse Wick Weeder) or small paintbrush to apply glyphosate precisely to Dallisgrass leaves. Avoid contact with St. Augustine. It's tedious but effective over time.

Work in sections weekly. Persistence reduces infestation to occasional spot treatments. Don't attempt blanket control—it kills the good grass too.

Pre-emergent herbicides don't control established perennial Dallisgrass.