How Long Does It Take Spectracide to Kill Grass?

Time To Kill

• With three active ingredients -- diquat, Fluazifop-p-butyl and dicamba -- Spectracide Weed & Grass Killer works quickly to exterminate more than 155 types of weeds, including weedy grasses and shrubs. Treated weeds or grasses show signs of damage within three hours, and begin to wilt and turn yellow within 24 hours. They will completely die, including the roots, within one to two weeks.

A Killing Mixture

• To kill grasses, annual, perennial, and shrubby weeds, mix 7 ounces of Spectracide Weed & Grass Killer in 1 gallon of water. To use on annual weeds only, mix 5 ounces of herbicide in 1 gallon of water. For newly emerged weeds that are still tender, mix 3 ounces of herbicide in 1 gallon of water. The mixture can be applied with a tank or hose-end sprayer. An area should not be treated more than twice a year.

Spray To Kill

• For best results, apply Spectracide Weed & Grass Killer when the grass or weeds are actively growing. Choose a calm, sunny day when the temperature is above 60 degrees Fahrenheit and no rain is predicted within 24 hours. Completely wet the blades of unwanted grasses or the leaves of weeds. Cover or block desirable plants with cardboard or plastic. If the spray touches desirable plants, immediately wash the spray off. Do not mow, cut or disturb treated plants for at least seven days. Spectracide Weed & Grass Killer is rain proof after 15 minutes, so rain or watering soon afterward will not reduce its effectiveness.

Warnings

• Do not use Spectracide Weed & Grass Killer on weeds in lawns, as it will also kill the grass. Do not use around edible plants or crops. Keep people and pets out of the treatment area until the spray has completely dried. Wear long sleeves, long pants, socks, shoes and gloves when applying herbicides. Do not get this chemical on your skin or in your eyes. Immediately wash exposed skin with soap and water after applying the product. Wash contaminated clothes in hot water and soap, separately from other laundry. Spectracide Weed & Grass Killer is toxic to aquatic invertebrates. Do not allow spray drift to contaminate bodies of water. Do not allow pesticides to run off into ditches, gutters, drainage systems, or bodies of water. Rinse any equipment you used over treated area to avoid contaminating other areas of your yard.