When is the best time to plant grass seed for fast growth?

[Mack]

My lawn has several patchy areas that need serious repair before summer hits. I’m looking for the ideal window where the soil temperature is just right to ensure the roots take hold quickly. In your experience, when is the best time to plant grass seed to avoid having the new growth scorched by the sun or washed away by heavy spring rains?

 

[Evelyn]

Plant grass seed in early fall or spring when temperatures are mild. Cool-season grasses grow fastest in fall, while warm-season grasses perform best in late spring to early summer.