Lime is a soil amendment derived from ground limestone, composed primarily of calcium carbonate. Its main purpose in lawn care is to neutralize soil acidity, a process known as raising the soil’s pH. This adjustment is frequently necessary in North Carolina, where heavy rainfall and natural geology often lead to acidic soil. When the soil becomes too acidic, essential nutrients like nitrogen, phosphorus, and potassium are chemically locked up and become unavailable to the grass roots. Applying lime helps correct this imbalance, allowing the turf to absorb fertilizer more effectively and promoting healthier growth.
Determining Your Lawn’s Specific Needs
The only reliable method to determine if your lawn needs lime is through a professional soil test, which provides an accurate measurement of the current soil pH. In North Carolina, the primary resource for this analysis is the Agronomic Division of the North Carolina Department of Agriculture & Consumer Services (NCDA&CS). Homeowners can obtain specialized sample boxes from their local NC State Cooperative Extension Office to submit a sample for testing.
The laboratory report will indicate the current soil pH and calculate the exact amount of lime required, given in pounds per 1,000 square feet. For common turf types in the state, including Tall Fescue, Bermuda, and Zoysia grasses, the target pH range is typically between 6.0 and 6.5. This range ensures maximum nutrient availability. Applying lime without this official recommendation risks over-liming, which can be just as detrimental to turf health as having overly acidic soil.
The Best Time to Apply Lime in NC
The most effective time to apply lime in North Carolina is generally during the fall. Lime reacts slowly with the soil, often taking several months to fully integrate and adjust the pH level before the next active growing season. The cooler temperatures and increased moisture from fall and winter rains help facilitate this chemical reaction by moving the lime down into the root zone.
For cool-season grasses like Tall Fescue, which thrive in the piedmont and mountain regions, the optimal window for liming is late summer through early fall (typically August through October). This timing ensures the pH correction is underway well before the grass enters its vigorous growth period in the spring. Applying lime in the fall also avoids stressing the fescue during the heat of the summer.
Warm-season grasses, such as Bermuda and Zoysia, should also be limed in the fall or very early spring. A late fall application allows the lime to work throughout their dormant winter period, preparing the soil for their active summer growth. Avoid application when the grass is under stress from extreme heat, drought, or when the ground is frozen solid.
Choosing the Right Product and Application Method
After confirming the need and application rate, select the correct product. The two most common forms are pulverized (or agricultural) lime and pelletized lime. Pulverized lime is a fine powder that is often difficult to spread evenly and creates a significant amount of dust, making it less ideal for residential properties.
Pelletized lime is pulverized lime compressed into small, easy-to-handle granules with a binding agent. This form is preferred by homeowners because it can be spread with a standard drop or rotary spreader with minimal dust. Never apply more than 50 pounds of lime per 1,000 square feet in a single application to prevent soil shock.
To ensure even coverage, apply half of the material while walking in one direction across the lawn, and then apply the remaining half perpendicular to the first pass. Immediately after application, water the lawn thoroughly. This watering washes any lime particles off the grass blades to prevent leaf burn and starts the process of dissolving the lime so it can begin reacting with the soil.