Grass can transform a landscape, creating a clean, lush appearance. Sow grass seeds when the temperature is mild. Intense summer heat and cold winters will slow root growth and kill grass seed.
Use the soil temperature as a guide when sowing grass seeds. Cool-season varieties need a temperature of 10 to 18.3 degrees Celsius, whereas warm-season grasses should be planted in soil temperatures of 18.3 and 21.1C. In the south, disperse the seeds at least 60 days before the first expected frost. In the north, sow the seeds at least 90 days before the first frost.
Sow grass seeds in the spring. April is the ideal time unless there is an early warm-up, in which case they then can be planted in March. Give the seeds ample time to germinate before the heat sets in.
If you miss the spring planting window, plant cool-season grasses in the early fall. The goal is to plant the seeds before it gets too cold. Between August 15 and September 15 is ideal.