Maybe the answer to this dilema is, give your grass some credit. It knows how to grow and even reseed itself.
Here's a few tips for healthy nontoxic lawn care.
1. Water only in the early morning, before 10 a.m. Water only if needed. Did you know your lawn most likely only needs 1" of rain a week.
2. Let your grass grow at least 3" before mowing. It will establish a healthy root system and will be much more lush. Grass clippings if left on the lawn and not bagged become a natural fertilizer for your yard so leave them, and let them do their job.
3. If fertilizing is a must then do it sparingly and in early fall. Fertilizing is best done after a rain, not before it. You don't want all the fertilizer to end up as run off in a heavy rain and end up straight in your water supply and harbors.