Barrier® Ornamental Landscaping Herbicide delivers dependable control of annual and perennial weeds, including dandelion, crabgrass, bluegrass, ragweed, and lambsquarters. Activated with rainfall or irrigation, the active ingredient of Barrier washes off the granule and attaches to soil organic matter. It then creates a “vapor barrier” in the upper two inches of the soil that slowly kills existing shallow-rooted weeds and grasses. Designed for use in established landscape and non-crop settings, Barrier is ideal for institutional sites such as hospitals, sport facilities, cemeteries, and apartment complexes.