Zoysia grass is a warm-season turf known for its dense, carpet-like growth, making it a popular choice for lush lawns. Proper mowing height is important for maintaining the health and appearance of this grass. Cutting Zoysia at the correct height encourages a thick canopy and robust root development, helping the lawn resist weeds and drought stress. Improper cutting can lead to scalping, which exposes the soil, or excessive thatch buildup.
The Recommended Cutting Height for Zoysia
The recommended height range for Zoysia during the active growing season is between 1 and 2.5 inches above the soil line. For a standard, healthy residential lawn, maintaining the height closer to 1.5 to 2.5 inches is advised. This range supports deeper root systems and better tolerance to environmental stress. This height is often achievable with a standard rotary mower, provided the blades are kept sharp.
Achieving a highly manicured, golf-course appearance requires cutting the grass at the lower end, sometimes 0.5 to 1 inch. This necessitates using a specialized reel mower for a precise cut. Cutting the grass too short, known as scalping, removes too much leaf tissue, which is the plant’s primary energy source for photosynthesis. This weakens the plant, making it vulnerable to heat stress, disease, and weed invasion. Allowing the grass to grow too high promotes excessive thatch buildup, which harbors disease and restricts air and water movement to the soil.
Mowing Frequency and the One-Third Rule
Mowing frequency is governed by the “one-third rule.” This rule dictates that you should never remove more than one-third of the grass blade’s total height in a single session. For example, if the lawn is maintained at two inches, you should mow before the grass reaches three inches tall. Cutting more than one-third stresses the plant by removing too much photosynthetic leaf area, which can cause the root system to shrink.
Since Zoysia grows vigorously during the summer, adhering to this rule often requires mowing every five to seven days during peak growth periods. Allowing the grass to grow too tall before mowing violates the one-third rule when attempting to return it to the desired height, resulting in a stressed, brown, and patchy appearance. Frequent mowing, even a light trim, is necessary to maintain a low, dense canopy without causing damage. This consistent schedule prevents stem tissue from growing too tall, which contributes to thatch.
Adjusting Height Based on Zoysia Variety and Climate
The specific Zoysia variety influences the ideal cutting height, as cultivars have different textures and growth habits. Fine-bladed varieties, such as Emerald or Zeon, tolerate and look best at the lower end of the recommended range, sometimes as low as one inch. Coarser-textured types, like Meyer or Palisades, perform better when maintained at a slightly greater height, closer to 2 to 2.5 inches. Using a higher cut on these coarser types helps prevent scalping, especially on uneven ground.
Climatic conditions and seasonal changes require adjustments to the cutting height to support turf health. During periods of extreme heat or drought, raising the mowing height slightly, by about half an inch, provides more leaf area for food production and helps shade the soil. This temporary increase helps the grass conserve moisture and improves resilience during challenging weather. In the fall, continue mowing at the normal height until growth significantly slows, preparing the turf for winter dormancy.