Grass transforms your landscape, giving it a defined appearance and purpose. You should broadcast grass seed before winter, so it has time to germinate and develop roots before the weather turns cold.
Grass seed should be sowed in late summer or early fall. The ideal time to plant cool-season grasses is between Aug. 15 and Sept. 15. If you've missed that window, you may still plant it until late autumn. Warm-season grasses may be planted in the fall, too. If you live in southern states, you should not plant this type later than 60 days before the first frost. In northern areas, the rule of thumb is 90 days before the first frost.
Even though you may disperse seed in late autumn, seeds may not have time to germinate before the temperatures fall. The seeds may remain dormant all winter and sprout when spring arrives. The risk is that the seed may be washed away or blown away during winter.
Warm-season grass seed has the best results when planted in soil temperatures of 18.3 to 21.1 degrees Celsius. Cool-season grass likes a soil temperature between 10.0 and 18.3 degrees C.