Warm season grasses describes a group of grass species that grow best during the hotter times of the year. These grass species have a shorter growing season as compared to the cool season grasses. The warm season grasses green up slower in the spring and go dormant earlier in the fall - usually after the first frost. Warm season perennial grasses take longer to germinate and establish than cool season grasses and usually requires soil temperatures to be 65 to 70 degrees Fahrenheit to begin germinating. The warm season grass species will have the highest forage productivity in late spring to early fall. The cool temperatures will slow the growth of these plants as they are protecting themselves for survival. As you will see below. Some warm season species will perform better under lower moisture conditions than others as they have deeper root systems, allowing them to reach deeper for moisture to survive.