Zoysia grass is a popular warm-season turf known for its remarkable density and durable texture. This grass variety creates a lush, carpet-like lawn that withstands heat and traffic, making it a desirable choice for many homeowners. Maintaining this quality requires consistent and specific cultural practices. Proper treatment includes routine care and targeted corrective actions to address environmental stress, competitors, and biological threats.
Essential Routine Maintenance
The foundation of a healthy Zoysia lawn rests on three pillars of consistent maintenance: correct watering, precise mowing, and timely fertilization. Zoysia thrives best when watered deeply but infrequently, encouraging a robust, deep root system that increases its drought tolerance. Aim to provide about one to one and a quarter inches of water per week, allowing the turf to show early signs of wilt before irrigating again. When watering, ensure the moisture penetrates the soil to a depth of four to six inches.
Maintaining the correct mowing height is important for Zoysia’s health and appearance. Zoysia performs optimally when kept between one and two inches in height. Frequent mowing is necessary during the active growing season (roughly every five to seven days) to avoid removing more than one-third of the blade length at any single time, which prevents scalping and stress. Leaving the clippings on the lawn, known as grass-cycling, recycles nutrients back into the soil.
Fertilization should be timed to support Zoysia during its peak growth period in the late spring and summer months. The turf requires a nitrogen-heavy formula, often with a ratio like 4-1-2, to maintain its rich color and density. Apply the first feeding a few weeks after the grass has fully greened up in the spring, avoiding early applications that could prematurely encourage top growth before root development. Subsequent applications of a slow-release nitrogen fertilizer can follow every four to eight weeks, though the total annual nitrogen application should not exceed four pounds per 1,000 square feet.
Managing Weeds and Other Invasive Species
Controlling competing plant life is necessary to maintain the dense, uniform texture of Zoysia grass. The most effective preventative measure is applying a pre-emergent herbicide in the early spring to create a chemical barrier that stops weed seeds from germinating. This application is timed when soil temperatures reach 55°F to 60°F for several consecutive days. A second application eight to ten weeks later can help ensure season-long control of summer annual weeds like crabgrass and foxtail.
For established weeds, a post-emergent herbicide provides corrective treatment. These products control existing broadleaf weeds, such as clover and spurge, and competing invasive grasses. Select selective herbicides specifically labeled as safe for Zoysia grass, as the turf can be sensitive to certain chemicals, especially during hot summer temperatures. Avoid applying post-emergent products during the initial spring green-up period. Spot-treating individual weeds is preferable to a broadcast application across the entire lawn.
Mechanical Treatments for Soil Health
Zoysia grass requires periodic mechanical treatments to manage its unique growth habit. Zoysia is known for producing a thick layer of thatch—an accumulation of dead stems, leaves, and roots between the soil surface and the green blades. When thatch exceeds a half-inch in thickness, it impedes the movement of water, air, and nutrients into the root zone. This creates a favorable environment for pests and diseases.
Dethatching, or verticutting, uses a machine to physically cut through and remove excess organic matter. This process should be performed during the active growing season, typically mid-summer, to allow the turf time to recover from the physical stress. Alternatively, core aeration manages moderate thatch buildup and improves soil structure. Aeration involves removing small plugs of soil, which relieves compaction and increases the exchange of oxygen and water to the roots.
Identifying and Treating Pests and Diseases
Corrective treatment often involves addressing specific biological threats, including insects and fungal pathogens. Common insect pests include white grubs, which feed on roots and cause brown patches that lift easily from the soil. Other pests are chinch bugs, which suck sap causing yellowing spots, and sod webworms, whose larvae chew the leaves. Identifying the pest accurately, often using a soap flush technique for surface insects, is the first step before applying a targeted, labeled insecticide.
Fungal diseases are frequently triggered by improper watering or excessive humidity. The most damaging issue is Zoysia Patch, also known as Brown Patch, which appears as circular patches of brown or tan grass. This disease is often associated with extended moisture, poor drainage, or over-fertilization. Other common fungi include Dollar Spot, linked to nitrogen deficiency, and Rust, which presents as an orange-red powdery film on the blades. Serious or persistent fungal outbreaks may necessitate the application of a specific fungicide, applied uniformly and according to label instructions.