Not only does lime not kill grass, it can benefit lawns and pastures.Too much lime will damage grass, but when you apply lime properly it corrects the imbalance of acidity in your soil, creates the optimum pH level and increases the ability of your grass to access nutrients.

Composition

Agricultural lime, also known as "ground limestone" also known simply as "lime," is a compound of calcium or calcium and magnesium.

Types

The most common and inexpensive form of lime is calcium carbonate. Ground limestone and calcic limestone are close to 100 percent calcium carbonate. This is the most available and easiest to handle type of lime. Burnt lime is twice as effective as calcium carbonate and faster acting, but it is caustic. Wear gloves when handling it.

Hydrated lime, also called slaked lime, also works faster and more efficiently than calcium carbonate(See reference 1).

Effects

Lime can make the difference between yellowing, brownish lawn or pastureland and lush, green, healthy grass. By creating the proper acidity, lime enables grass to achieve optimum growth and overpower invaders such as moss. Although lime supplies calcium and magnesium, it is not a fertilizer, but rather a soil amendment or conditioner. It promotes plant growth by inhibiting solubility of toxic elements in the soil and maximizing absorption of beneficial nutrients. By increasing bacterial activity, it "induces favorable soil structure and relationships," according to West Virginia University.

Analysis

If you're giving your grass adequate water and fertilizer, and it is sparse, yellow and brown, test your soil's pH. A result of 5.5 or below indicates high acidity and applying lime could solve the problem. West Virginia University advises a pH 6.5 to pH 7.0 for optimum grass growth.

Application

Apply lime pellets at the rate of 40 lb. per 1,000 square feet two to three times per year and consult local gardening experts for recommendations pertaining to your location. West Virginia University advises you to apply lime to the top soil and subsoil when preparing for planting. You can lime established lawns any time of year, but fall is the best. The amount of lime to use will vary with the degree of acidity, the soil type and the kind of lime. Test the soil to be sure. Avoid the damage caused by overliming by not exceeding 150 lb. lime per 1,000 square feet and liming only once every three to five years. Overliming can be as detrimental to grass as an overly acidic soil.