Grass Herbicides . Preemergence herbicides that are most effective on grass weeds include Pennant, Devrinol, Barricade, Pendulum, Surflan, and Treflan. Pennant provides good preemergence control of nutsedge in addition to annual grasses. It is labeled on many woody ornamental species and also some ground covers, bulbs, and herbaceous plants. To reduce the chance of injury, wash this product from the foliage of desirable ornamentals when applied over the top.
Image is a new product that also controls nutsedge by pre- and early postemergence applications.
However, it has a limited label for landscape ornamentals. Devrinol is a good choice for fall herbicide application because warm temperatures and light reduce its effectiveness and longevity. However it may be used in the warm season if followed by adequate irrigation or incorporation. Devrinol may be broadcast over the tops of liners, container and field stock, as well as some ground covers and flowers. In addition to grassy weeds, Devrinol provides good control of chickweed.