Ryegrass should be planted in the early fall. It is a cool season landscaping grass that is popular with homeowners in the upper half of the United States.
The best conditions for growing ryegrass are when soil temperature is between 50 and 65 degrees Fahrenheit and the air is between 60 and 75 degrees. If the air temperature is above 90 or below 50 degrees, the grass stops growing. There is also sufficient rainfall in the autumn and the grass has time to develop before the killing frosts of winter. Spring is considered the second best time to plant ryegrass and it is a good time to overseed if the lawn has winter damage.