Read the label on the can or package. Three to six weeks is the average. She should rake out all the dead grass, put down a 1/8th inch layer of compost, spread the grass seed and keep it watered. If it dries out, it will die. Best and Happy Yardening, Nancy
How Long To Wait After Lawn Killer Before Reseeding
Question From: M. Cunningham - WASHINGTON
Q: My mother accidently used a grass killer instead of a weed killer on her lawn and killed large sections of her grass. It's been about 8 weeks since she applied it. Can she reseed at this point? Does she have to rake out all the dead grass or just sprinkle seed over the dead grass and hope for the best?