Zoysia grass is a popular warm-season turf known for creating a dense, carpet-like lawn. It possesses excellent tolerance to heat and drought, spreads vigorously, and withstands heavy foot traffic well. To maintain its vibrant green color and density, a precise fertilization strategy is required throughout its active growing season. Proper nutrient management ensures Zoysia remains healthy and prevents issues associated with over- or under-feeding.
Understanding Zoysia’s Specific Nutrient Requirements
The first step in any successful fertilization plan is determining the current condition of the soil. A professional soil test provides an accurate baseline, revealing nutrient deficiencies and the current soil pH. Ideally, the pH should be slightly acidic, ranging between 6.0 and 6.5. Zoysia’s primary nutrient demand is for Nitrogen (N), which is responsible for deep green color and vigorous leaf growth. The annual requirement for established Zoysia falls between 2 and 4 pounds of actual nitrogen per 1,000 square feet, depending on the desired maintenance level.
When selecting a fertilizer, look for products high in nitrogen, such as a 3-1-2 or 4-1-2 ratio (e.g., 16-4-8), especially for the initial spring feeding. The nitrogen source composition is significant because Zoysia is prone to thatch buildup. Using a fertilizer that incorporates slow-release or water-insoluble nitrogen is recommended to manage growth. This delivers a steady, controlled supply of nutrients, preventing the sudden surge growth that leads to excessive thatch and potential turf burning.
Optimal Timing for Fertilization Throughout the Year
The fertilization calendar for Zoysia grass is built around its warm-season life cycle, ensuring nutrients are available only when the grass is actively growing. The schedule is divided into three distinct phases to align with the grass’s needs as temperatures fluctuate.
Spring Green-Up Application
The first feeding, the Spring Green-Up application, should not occur until the grass has fully exited dormancy and is completely green. A reliable indicator is when the soil temperature consistently reaches 65 degrees Fahrenheit at a depth of four inches, signaling vigorous root growth. Applying fertilizer too early risks feeding cool-season weeds before Zoysia roots are fully functional. This initial application provides the energy needed for the grass to awaken from winter dormancy.
Summer Maintenance
The Summer Maintenance phase requires lighter, more frequent applications during the peak growing season (late spring through late summer). These subsequent feedings should be spaced four to six weeks apart to maintain consistent color and density without causing excessive growth. During intense summer heat, a fertilizer including a high percentage of Potassium (K) is beneficial. This nutrient enhances the grass’s ability to manage heat stress, drought, and disease.
Late Summer/Early Fall Preparation
The final application is the Late Summer/Early Fall Preparation phase, designed to fortify the grass before winter dormancy. This light feeding must be timed well before the first expected frost so the grass can utilize the nutrients. Avoid applying heavy nitrogen at this time, as it promotes tender new growth highly susceptible to winter injury. Instead, if a soil test indicates a need, focus on potassium to bolster the turf’s cold hardiness and root strength throughout the dormant season.
Practical Application Methods and Rates
Determining the correct amount of fertilizer relies on the lawn’s square footage and the product’s nitrogen content. To ensure a rate of 0.5 to 1 pound of actual nitrogen is applied per 1,000 square feet, use the fertilizer bag’s analysis for calculation. For example, to apply 0.5 pounds of nitrogen, divide 50 by the first number in the NPK analysis; the result indicates the pounds of product needed per 1,000 square feet.
Applying fertilizer with a rotary or drop spreader is the most effective way to achieve even coverage and prevent streaks or burn marks. Before application, the spreader must be calibrated according to the manufacturer’s directions for the specific product. It is helpful to treat the lawn’s perimeter first to create a border. Then, apply the fertilizer in parallel passes, slightly overlapping each path to eliminate gaps in coverage.
A step immediately following the application of granular fertilizer is thorough watering. Watering activates the fertilizer, moving nutrients off the grass blades and into the soil for root absorption. This action prevents fertilizer burn, which occurs when granules remain in contact with moist leaf tissue and dehydrate the plant cells. Promptly watering in the product ensures Zoysia receives the intended benefit without suffering damage.