What is the best ratio for lawn fertilizer?

There is not a "best" ratio for a lawn fertilizer. In the springtime, when the turfgrass plant is actively growing, a fertilizer such as Lawn Food with a higher "N" ratio is recommended. For a new seeding or a fall fertilization, the "N" component is not typically as high as a lawn fertilizer. Examples of those fertilizers would be an All Season Lawn Starter or Fall Feed. These products are closer to a more balanced ratio of nitrogen, phosphorus and potassium.