Spring seeded lawns may require regular irrigation during hot dry periods. According to Tom Voigt, Extension turfgrass specialist with the University of Illinois Department of Natural Resources and Environmental Sciences, two factors are critical for successful grass seedings. First be sure the seed is in good contact with the soil. Lightly raking and rolling bare soil after seeding is recommended. If you are just trying to thicken an existing lawn, use a slit seeder or another type of machine such as a vertical mower to get the seed down in the soil.
Seed scattered over existing turf is just expensive bird seed.
Mow lawn frequently so as not to remove more than one third of the grass blade at any one mowing. Most lawn grasses should be mowed to between two to three inches tall. Clippings do not have to be removed from the lawn unless they remain visible for 24 hours after mowing. The first full fertilizer application of the season should be applied the first two weeks in May. May. What you don't need to do in the spring is apply grub control products.