Lime is a valuable soil amendment that helps plants and lawns flourish by raising soil pH. A low soil pH, or acidic soil, is often the underlying problem when it comes to many common lawn and garden problems. But even with a healthy lawn or garden, liming can improve soil quality, helping plants and grass to flourish.

Lawns need lime when low soil pH starts inhibiting the availability of nutrients.  Lime restores balance in overly acidic soil to bring pH back to optimal growing levels. Poor grass growth, bare areas and lawn moss are signs that lawns need lime.

In Massachusetts lawns generally have low pH levels.  When maintained, you should only need one application of lime per year to maintain a healthy pH.  Newer lawns, or lawns that have not been fertilized, usually need two applications of lime in their first year. 

Read More: https://ag.umass.edu/turf/fact-sheets/soil-ph-liming