When Is the Best Time to Spread Lime on Zoysia Grass?

Application Time

• The Maryland Cooperative Extension recommends liming zoysiagrasses during fall. The requirement for lime is best determined by a soil test. On a general note, other experts also recommend using lime on lawns during fall. Other good times to lime include winter and very early spring. When applied at these times, damage to the grass is minimized.

Application Rate

• Lime is primarily added to soil to reduce acidity. On the pH scale of 0 to 14, any rate below 7.0 is acidic, 7.0 is neutral and a number above 7.0 is considered basic or alkaline. The majority of turfgrasses, including zoysiagrass, need a pH of 6.0 to 6.5 for optimal growth. Lime is recommended when pH is below 5.5. Apply at the rate of 25 to 50 pounds for every 1000 square feet of lawn to attain pH level of 6.0, cites the Maryland Cooperative Extension.

Sources of Lime

• The most commonly used lime is calcium carbonate or ground limestone. This also contains certain levels of magnesium carbonate and is preferred because it is less caustic, more economical and safer to handle. Another lime source is burnt lime, also referred to as caustic lime or quick lime. Though the material is fast acting, it requires the use of gloves as it can burn hands. Hydrated lime or slaked lime is also used for limelight and is slightly more effective and faster acting than calcium carbonate.

Purpose of Lime

• Though the main purpose of lime is to reduce soil acidity, the material also supplies magnesium and calcium to soil. Lime in soil helps to lower toxicity in soil caused by iron, magnesium or aluminum. The availability of certain nutrients like phosphorus, copper and zinc reduces for plants in acidic soils even if the nutrients are present in soil. Liming helps to fix this deficiency. Presence of lime in soil improves soil structure by increasing bacterial activity.