Zoysia grass is a popular warm-season turfgrass known for creating a dense, carpet-like lawn texture that feels soft underfoot. Classified as a warm-season variety, Zoysia thrives in hot climates and has a natural ability to withstand periods of drought once established. Its appealing density and bright green color during the growing season make it a favored choice for homeowners. Achieving this signature look requires a specific maintenance regimen that aligns with the grass’s unique growth habits and needs.
Mowing Practices for Zoysia
Maintaining the health and appearance of Zoysia grass begins with meticulous mowing, as this grass is typically maintained at a lower height than many other turf varieties. The recommended cutting height for standard Zoysia cultivars ranges between 1 and 2 inches. Keeping the lawn on the shorter end of this range encourages the dense growth habit.
Frequency is important, especially during the peak growing season of summer, often requiring weekly mowing or more. Never remove more than one-third of the grass blade’s total height in a single session. Violating this “one-third rule” stresses the plant, leading to a scalped appearance and leaving the grass vulnerable to disease and heat damage.
Zoysia’s coarse, tough leaf blades necessitate the use of a consistently sharp mower blade to ensure a clean cut. A dull blade will tear and fray the tips of the grass, causing a ragged, tan or brownish appearance as the damaged tissue dies back. Regular sharpening, which may be needed monthly during the summer, prevents this damage and helps the lawn maintain its uniform green color.
Watering and Irrigation Needs
The correct approach to watering Zoysia grass is to practice deep and infrequent irrigation, which encourages the development of a robust, drought-resistant root system. Shallow, frequent watering leads to roots that stay near the surface, making the grass highly susceptible to drought stress.
A deep watering application aims to saturate the soil to a depth of 6 to 8 inches, typically requiring about 1 to 1.5 inches of water per week, including natural rainfall. The actual frequency will vary depending on local weather and soil type.
The best time to apply water is in the early morning, ideally between 4 a.m. and 10 a.m., which allows the foliage to dry completely before nightfall. Watering in the evening or at night can leave the grass blades wet for extended periods, creating an environment that promotes the development of fungal diseases like dollar spot or large patch. Signs of drought stress, such as the grass blades folding in half or turning a gray-blue color, indicate that immediate watering is necessary.
Fertilization Schedule and Nutrient Requirements
The fertilization program for Zoysia grass is timed precisely to support its warm-season growth cycle. Before any application, a soil test is highly recommended to determine the existing nutrient levels and the soil’s pH, which ideally should fall between 6.0 and 6.5 for optimal growth.
Nitrogen is the most important nutrient for Zoysia’s green color and density. The first application should occur in the spring after the grass has fully greened up and the soil temperature has stabilized. Applying nitrogen too early can stimulate tender new growth that is easily damaged by a late cold snap.
Established Zoysia typically requires a total of 2 to 4 pounds of actual nitrogen per 1,000 square feet over the entire growing season. This is a relatively low requirement compared to other turfgrasses. This total is usually split into two or three applications between late spring and mid-August, using a complete fertilizer with an NPK ratio high in nitrogen, such as a 4-1-2 or 3-1-2 ratio (e.g., 16-4-8).
The final nitrogen application must be completed by mid-August to late August to prevent new growth that will be vulnerable to winter injury. An application of potassium in the fall, if a soil test indicates a deficiency, can enhance the grass’s winter hardiness and disease resistance.
Managing Thatch and Soil Compaction
Zoysia grass is highly susceptible to thatch buildup because of its dense growth habit and the coarse, slow-to-decompose nature of its runners and stems. Thatch is a tightly interwoven layer of dead and living organic matter that accumulates between the soil surface and the green grass blades. When this layer exceeds a half-inch thick, it becomes detrimental, blocking the movement of water, air, and nutrients into the root zone and creating an ideal environment for pests and diseases.
To combat excessive thatch, mechanical removal through dethatching or verticutting is necessary when the grass is actively growing and can recover quickly. The best timing for this renovation is typically during the mid-summer months, such as June or July. If the thatch layer is over one inch thick, it is best to remove it gradually over two to three years to prevent excessive damage to the lawn.
Core aeration is another practice that addresses both thatch and soil compaction, which is common in high-traffic areas or clay soils. This process removes small plugs of soil, creating channels that allow oxygen, water, and fertilizer to reach the deep root system. Aeration should also be done during the active growth season, and the soil plugs should be left on the surface to break down naturally.