Use on Landscape Ornamentals and Home Lawns Stops Broadleaf Weeds Before They Start. A pre-emergence herbicide for control of certain broadleaf weeds such as: Chickweed, Clover, Dandelion, Henbit, Spurge, Yellow Woodsorrel (Oxalis). Suppression of annual grasses such as: Annual Bluegrass (Poa Annua) and Crabgrass established in cool season and warm season turfgrass and landscape ornamentals. Apply late summer to fall, early spring, or anytime prior to germination of target weeds.