Lime corrects soil acidity, adds calcium and magnesium to the soil and regulates other beneficial soil nutrients. Grasses in soils with the wrong pH level turn yellow and patchy. Calcium and magnesium protect grass from heat, drought and traffic stress.
If soil pH falls below 6.0 or 7.0, lime should be added. Soils may become more acidic over time because of over fertilization, leaching or excessive rainfall. The incorporation of lime adds alkalinity, balancing out the acid, so the soil becomes more neutral. A simple soil test may be performed to determine the pH of soil.
Lime should be spread when grasses are planted. In lawns that are already established, the best time for spreading lime is in the fall. Don't apply lime at the same time as fertilizer as an adverse chemical reaction may occur.
Lime may be purchased in powder or pellet form. The pellet form can be easily applied with a broadcast spreader. Lime may also be applied directly by hand. Avoid windy days, and spread the lime in a crisscross pattern to ensure even coverage. Only apply lime when needed. Applying too much lime may result in lime-induced chlorosis. This makes the grass turn yellow and is difficult to correct.