The answer to 'lawn fertilization schedule' is that most lawns should be fertilized 2-4 times per year, with the first application in early spring and the last in late fall. The exact timing and number of applications can vary depending on your local climate, grass type, and lawn conditions.
In general, it's best to apply a balanced, slow-release fertilizer in early spring (March-April) to encourage healthy root growth and green-up. Then follow up with additional applications in late spring (May-June), mid-summer (July-August), and late fall (October-November) to maintain nutrient levels and prepare the lawn for winter. Be sure to follow the application rates and instructions on the fertilizer bag for best results.