Spectracide Weed Stop For Lawns, 1 Gallon Ounces kills all types of listed broadleaf weeds including dandelion, chickweed, clover and yellow nutsedge. This product treats bluegrass, fescue, zoysia, Bermuda and perennial ryegrass. For best results, apply between 45 degrees and 90 degrees. Application above 45 degrees, the better the weeds will be able to absorb the product. Spectracide Weed Stop For Lawns kills by contact and kills weed roots. Spectracide controls 460+ weeds as listed, giving you visible results in 3 hours. When used as directed, this product kills the weeds, not the lawn.Do not apply to zoysiagrass just emerging from dormancy.