Adding lime to your lawn...

Purchase lime by the bag, prilled is best.

Prilled lime is very fine lime rolled into "gravel" that breaks down very easily when wet.

Using a lawn spreader, following application directions on the bag, apply lime to the lawn in the fall.  The lime will "sweeten" the soil and help balance the pH.  Mushrooms growing anywhere in the lawn, and/or moss growing in sunny sections of the lawn, tell you it's time to add lime.

Fred Meyer carries the Lily Miller brand called Super Sweet.  At $6.48 for a 25 pound bag, it's an inexpensive solution to this problem.