Cool season grass types include ryegrasses, fescues and bluegrasses. There are many types of grass species that fall within the three main types of cool season grass, such as Kentucky bluegrass. The main difference between cool and warm season grass is growing season. Cool season grass types prefer to grow when temperatures are between 65 to 75 degrees Fahrenheit, according to the Turf Resource Center. Warm season grass needs air temperatures between 80 to 95 degrees Fahrenheit to grow.
Gardeners should check their soil temperatures as summer folds to a close to select a time to plant. Cool season grass, such as annual bluegrass, begins germinating when soil temperatures dip below 70 degrees Fahrenheit, according to the University of California. To check the soil temperature, press a screwdriver into your lawn to a depth of 6 inches to make a hole for your soil thermometer. Place the soil thermometer inside of the hole to obtain the temperatures. Check for several days to ensure that the soil temperatures remain consistent.
Remove all cool season weeds from your yard. Cool season weeds begin germinating at the end of summer to early fall. If left untreated, they will compete with your grass seed for the soil's nutrients. Spray the lawn area with a herbicide that contains glyphosate. Glyphosate works by inhibiting the weed plant's ability to produce protein. In addition, glyphosate leaves little residue in the soil. Till the lawn to break up the first 6 inches of top soil to help your cool season grass establish a strong root system.
Apply a starter fertilizer to the lawn. Distribute 20 pounds of a starter fertilizer with an NPK amount of 5-10-5 per 1,000 square feet and work into the first 4 to 6 inches of top soil, as suggested by the University of California. Pour your cool grass seed into a rotary grass seed spreader. Cool season grass types such as bluegrass should be distributed at a rate of 2 to 3 pounds per 1,000 square feet, according to Texas A&M University. Cover the grass seed with 1/8 of an inch of compost. Water.