Now is the time to reseed dead areas in your cool-season lawn, such as fescue and bluegrass. These areas should be reseeded between September 1 and mid-October. If this also involves killing any existing grass, kill these areas with an herbicide at least 2 weeks before planting seed. Stop fertilizing, dethatching, and core aerifying of warm-season grasses now. Resume again after green-up in late spring next year.
Gardening by Month