Grow Like A Pro Lawn Care Guide: Apply Grass Seed Protection
Step 7: Apply Grass Seed Protection 
Mulch and other protective coverings will conserve moisture and reduce the amount of lawn watering needed. It also helps keep grass seed from freezing in colder weather, from washing away in heavy rains and from being eaten by birds.
Straw is an adequate, inexpensive mulch. Allow 1 bale for every 1,000 square feet. Use our lawn area calculator formula to determine the square footage of your lawn. However, be aware that any live grass seed in straw can and probably will germinate with the new grass. Another drawback to using straw for grass seed protection is that decays slowly in your lawn.
Peat moss is a more expensive mulch, but offers some helpful benefits. It does not contain weed seed and easily decomposes into the soil.
Grow Like A Pro Program Brochure