The best time of year to plant grass depends on the type of grass being planted and the region where the grass is being planted. The two types of grass to take into consideration are cool season grass and warm season grass.
Cool season grasses are best planted within two weeks of Labor Day, so the roots have plenty of time to grow before winter and the frosts set in. Cool season grasses can also be planted in the spring. However, crab grass thrives in the spring and can overtake the freshly planted grass.
Warm season grasses should be planted when the temperature is between 75 to 90 degrees Fahrenheit. The best times to plant this type of grass include late spring, after the last frost or early summer.