Zoysia grass is a warm-season turfgrass highly valued for its dense growth habit and resilience in warmer climates. Achieving a healthy, vibrant lawn requires consistent nutrient delivery and a strategic fertilization plan. Unlike cool-season grasses, Zoysia thrives during the summer, so its fertilization schedule must strictly align with its active growth cycle. Proper timing and frequency are paramount to providing necessary nutrients while avoiding excessive growth, thatch buildup, and potential turf damage.
Timing the Initial Spring Application
The first fertilizer application depends on the grass’s emergence from winter dormancy, not a specific calendar date. Applying nutrients while the grass is still dormant can feed weeds and cause nutrient runoff. The lawn is ready for its first feeding when it is fully green and actively growing.
Active growth typically begins when the soil temperature consistently reaches 65 degrees Fahrenheit at a four-inch depth. Waiting until the grass has fully greened up, often in late spring, ensures that the roots are actively absorbing nutrients. This promotes healthy growth and avoids the risk of damage from an unexpected late frost.
Determining the Annual Fertilization Frequency
An established Zoysia lawn typically benefits from three to four fertilizer applications throughout the growing season. The annual goal is to supply two to four pounds of actual nitrogen per 1,000 square feet, divided across these applications. The lower rate is often sufficient for clay soils, while the higher rate suits sandy soils.
The general timeline starts in late spring or early summer, once the grass is fully greened and the soil is warm. Subsequent applications should be spaced four to eight weeks apart to sustain growth through the peak summer heat. A mid-summer application supports the grass during its most active period, helping it withstand high temperatures and drought stress.
The final application should occur in late summer or early fall to prepare the turf for dormancy. Nitrogen applications must stop at least six weeks before the first expected frost date. Applying nitrogen too late encourages new, tender growth that can be damaged by cold weather, interfering with the natural hardening process needed for winter survival.
Regional Adjustments and Special Cases
The standard three-to-four application schedule is often adjusted for Zoysia growing in transition zones or for lower-maintenance approaches. In northern transition zones, where the growing season is shorter, reducing the frequency to two applications may be appropriate. This helps prevent the grass from spending too much energy on growth just before cold weather returns.
Homeowners seeking a less intensively managed lawn can opt for a lower annual nitrogen rate, sometimes as little as two pounds per 1,000 square feet, resulting in fewer total applications. Newly established Zoysia, whether from sod or seed, requires a different approach. New sod or sprigs should receive light, more frequent feedings of a starter fertilizer until they are fully rooted.
Fertilizer Selection and Application Guidelines
Selecting the correct fertilizer formulation is important. Zoysia performs well with a fertilizer high in nitrogen, low or zero in phosphorus, and moderate in potassium (e.g., ratios like 4-1-2 or 3-1-2). A soil test is the best method to determine if your lawn needs a more balanced formula due to phosphorus or potassium deficiency.
Using a slow-release nitrogen source is recommended for Zoysia, as this provides a steady supply of nutrients over several weeks. Slow-release granules prevent the rapid flush of growth that leads to excessive thatch accumulation and reduce the risk of fertilizer burn associated with quick-release nitrogen. Each application should not exceed one pound of actual nitrogen per 1,000 square feet, especially when using a quick-release product.
After spreading the granular fertilizer evenly with a calibrated spreader, the lawn should be watered immediately. Watering washes the granules off the leaf blades, preventing burn, and dissolves the nutrients so they can be absorbed by the roots. Potassium is important in mid-to-late summer applications because it enhances the grass’s stress tolerance against heat, drought, and disease.