The answer to 'when to lawn' is that the best time to establish or reseed a lawn depends on the type of grass and your local climate. In most regions, the optimal times are in the fall (late August to October) or early spring (March to May).
Fall is generally the best time to plant cool-season grasses like fescue, bluegrass, and ryegrass. The cooler temperatures and increased rainfall provide ideal conditions for grass seed germination and establishment. Spring is better for warm-season grasses like bermuda, zoysia, and St. Augustine, which thrive in warmer weather.