Centipede grass is a popular choice for lawns throughout Georgia, valued for its low-maintenance requirements and ability to thrive in the state’s warm, humid climate. This warm-season turfgrass maintains a light, apple-green color and grows slowly, minimizing the need for frequent mowing. Achieving a healthy, uniform centipede lawn depends heavily on a precise fertilization schedule that caters to its minimal needs. Applying fertilizer at the correct time and with the appropriate composition is paramount to supporting its natural growth cycle.
The Ideal Fertilization Calendar for Georgia
The precise timing for fertilizing centipede grass in Georgia is dictated by soil temperatures, which signal the start of active growth. Homeowners should wait until the 4-inch soil temperature consistently reaches 65 degrees Fahrenheit before applying any nitrogen fertilizer in the spring. This threshold typically occurs in late April or early May across much of Georgia, ensuring the grass is fully out of winter dormancy. Applying fertilizer too early can promote vulnerable new growth susceptible to late frosts or disease.
Centipede grass is often called the “lazy man’s grass” because it requires far less fertilizer than other warm-season varieties like Bermuda or Zoysia. For established lawns, a single, light application of fertilizer in late spring is often sufficient to maintain health and color throughout the growing season. A second, optional application can be made in mid-summer, typically in July, but only if the lawn shows signs of needing a boost.
Avoid fertilizing centipede grass in the late summer or fall, especially after August. Applying nitrogen late in the season encourages a flush of tender new growth that lacks the necessary hardiness to survive winter temperatures. This late-season growth significantly increases the risk of winter injury and contributes to turf decline. Limiting the annual fertilizer program to one or two light applications during the peak growing season is the best strategy for long-term centipede health.
Understanding Centipede Grass’s Specific Nutrient Needs
Centipede grass has a low nitrogen (N) requirement; over-fertilization is the primary cause of decline in this turf type. Most Georgia centipede lawns require only between 1 and 2 pounds of actual nitrogen per 1,000 square feet per year, often split between the one or two summer applications. Using high nitrogen rates can lead to excessive thatch buildup, increased susceptibility to disease, and winter kill.
The yellowing of centipede grass, known as chlorosis, is a common problem in Georgia often mistaken for a nitrogen deficiency. This yellowing is usually caused by an iron (Fe) deficiency, particularly in the state’s common clay soils where the pH is higher. Applying a supplemental iron product, such as ferrous sulfate or a chelated iron source, can quickly restore the green color without promoting excessive growth.
Phosphorus (P) should be avoided unless a soil test confirms a specific deficiency, as centipede grass is sensitive to high phosphorus levels. A recommended nutrient ratio that limits nitrogen and excludes phosphorus is a low-N, zero-P blend such as 15-0-15. This blend provides the necessary nitrogen and potassium (K) for plant health while preventing the negative effects associated with high phosphorus and excessive nitrogen.
Soil Preparation and Application Techniques
Conducting a soil test is a necessary first step before applying any fertilizer, especially due to centipede grass’s sensitivity to soil conditions. Centipede grass thrives in acidic soil with a pH range between 5.0 and 6.0. Many Georgia soils, particularly in the northern regions, can have a higher pH, which locks up iron and causes the characteristic yellowing.
If the soil test reveals a high pH, a soil acidifier like pelletized sulfur can be applied to lower it, making nutrients more available. Sulfur should be applied in small, measured increments, with no more than 5 pounds per 1,000 square feet in a single application. Apply sulfur only when air temperatures are below 80 degrees Fahrenheit. Retest the soil after a few months to track the pH change, as large adjustments can take time.
When applying granular fertilizer, the product must be spread evenly across the lawn using a properly calibrated broadcast or drop spreader. The application should be made when the grass blades are dry to prevent the granules from sticking and causing leaf burn. After application, the lawn must be watered immediately with about a quarter to a half-inch of irrigation to wash the granules into the soil. This watering step ensures the nutrients begin dissolving and prevents chemical burn on the turf.