Our easy-to-use insect, lawn disease and weed control solutions help tame lawn and landscape invaders with incredible pest-punishing power. Our Spectracide Weed Stop For Lawns . This product treats bluegrass, fescue, zoysia, Bermuda and perennial ryegrass. For best results, apply between 45 degrees and 90 degrees. Above 45 degrees, the better the weeds will be able to absorb the product. Lawn damage could happen above 90 degrees. This easy-to-use product is designed with the QuickFlip sprayer, allowing you to just connect your hose and spray at the flip of a switch. When used as directed, this product kills the weeds, not the lawn. Do not apply to zoysiagrass just emerging from dormancy.