You can apply Agralawn Crabgrass Killer in the morning while morning dew is present for the best results, or you can wet the affected area with a hose, irrigation or spray bottle before applying Agralawn. When this product is used properly, Agralawn Crabgrass Killer causes very little reaction to St. Augustine or Bahia lawns. Apply Agralawn only to the affected area, being careful to spread it over all the weeds and/or weed-grass you want to control. Apply a light to medium coating in even strokes. Noticeable results should be seen in 3 to 5 days. To avoid washing away the product, don’t apply it if rain is forecasted or directly before watering the lawn. Reapply it as needed.