Weed Control and Grass Seeding
Don’t apply pre-emergent weed control if you have seeded your lawn, as the pre-emergent weed control will kill the developing seeds. Instead, wait until after your grass seed has germinated and started to grow.
Grass Seeding:
Don’t plant cool season grass seed in the spring. Planting in spring
exposes the seedlings to fusarium blight and other disease pathogens,
plus the new grass will be exposed to the summer heat before their roots
have had a chance to develop. Fall is a better time to plant cool
season grass seed.
Fertilizer
Don’t over-fertilize. A little fertilizer is good, but too much too early in the spring can cause problems like lots of topgrowth. Although it may look nice at first, topgrowth comes at the expense of your lawns roots. Rather than go heavy on fertilizer in the spring, it is better to fertilize lightly throughout the season.
Pest Control:
Don’t use pest control as a preventative measure. Pesticides are expensive and some can cause significant damage to the environment. If you don’t have an actual problem with lawn insects, then don’t use insecticides. And similarly, if you don’t have a disease problem, then don’t use fungicides.