Selecting the appropriate fertilizer and application rate should be based on soil test results.
The Best Time to Fertilize
The best time to fertilize a Kentucky Bluegrass lawn is in the Fall and again in the Spring. Spring fertilization will assist in green up of the lawn and provide food during the shoot development stage of turfgrass growth. Fertilization should decrease in the summer months when Kentucky Bluegrass is normally under stress in our region. As temperatures moderate in the fall a fertilizer application is important to coincide with major root development. An additional late fall fertilization after the first frost will also increase the turf quality the following spring.