A newly seeded lawn requires proper feeding to become well established. Grass seed started off healthy is more likely to remain healthy and not become prone to bald spots or disease. Fertilizer comes in a combination of nitrogen, phosphate and potassium. Most new lawns require more phosphate than the other two chemicals. PH testing before you seed is recommended to discern the exact type of fertilizer required, but in most cases a general seed-starting fertilizer is sufficient. Phosphate percentage is shown as the center number of the fertilizer percentage written on the bag.
Apply the first course of fertilization before sowing the grass seed. Use a slow-release fertilizer that will feed the new grass for at least the first two months.
Adjust the settings on your fertilizer drop spreader so it is set to drop the amount per square foot as recommended on the back of the fertilizer bag. In general, set it to drop 8 lb. per 1,000 square feet of lawn.
Close the chute on the spreader and fill half-full with the fertilizer mix. Move the spreader to your starting position on the lawn.
Open the spreader chute. Push the spreader in horizontal rows across the lawn, walking at an even pace. Close the chute if you need to stop pushing for any reason so the fertilizer does not continue to run onto the soil and over-fertilize an area.
Till the fertilizer into the top 4 inches of the soil once it's applied. Till in using a hand tiller or a roto-tiller.
Seed the lawn within 48 hours of applying the fertilizer.
Apply a nitrogen-rich fertilizer once the new grass is 2 inches tall. Apply .5 lb. of nitrogen per 1000 square feet of lawn using the same method for the initial fertilization.