Zoysia and Bermuda grass are popular warm-season turf species used across the southern United States. Both are valued for their heat tolerance, drought resistance, and ability to create a dense lawn surface. Homeowners often consider mixing them to combine benefits, such as Zoysia’s shade tolerance and Bermuda’s rapid recovery. However, turfgrass professionals strongly discourage mixing Zoysia and Bermuda grass. Fundamental differences in their biological mechanisms and growth rates inevitably lead to intense competition and a visually inconsistent lawn.
Understanding the Growth Habits
The primary challenge in mixing these grasses lies in the significant differences in their spreading mechanisms and vigor. Bermuda grass is a highly aggressive turf that spreads rapidly using both above-ground runners (stolons) and underground stems (rhizomes). This dual-spreading habit allows it to quickly colonize open ground, recover from damage, and outpace slower-growing turf species.
Zoysia grass also utilizes both stolons and rhizomes, but its growth rate is notably slower than Bermuda’s, especially during establishment. While Zoysia eventually forms a dense, carpet-like turf, its slower initial spread is a distinct disadvantage when competing for resources. Bermuda grass will aggressively invade and eventually crowd out Zoysia patches, particularly in areas with full sun exposure where Bermuda thrives.
The speed of growth dictates the resource requirements for each species. Bermuda grass is a higher-maintenance turf demanding higher nitrogen fertilization rates to support its vigorous nature. Zoysia has a lower nitrogen requirement and a slower growth rate, meaning it cannot sustain the same level of competition when resources are plentiful. This mismatch ensures that the more aggressive Bermuda grass quickly becomes the dominant species in a mixed lawn.
The Resulting Aesthetic Conflict
Beyond biological competition, a mixed Zoysia and Bermuda lawn creates a visual conflict. The texture of the two grasses is distinctly different, resulting in a patchy and inconsistent surface. Bermuda grass has fine, thin leaf blades, typically measuring between 1.5 and 1.7 millimeters wide.
Zoysia grass generally has wider leaf blades, ranging from 2 to 7 millimeters, creating a thicker, denser turf. When these two textures grow side-by-side, the uniform appearance of a single-species lawn is lost, replaced by a mottled look.
The seasonal color and dormancy cycles further compound the aesthetic problem during transition periods. Bermuda grass is often a lighter green, while Zoysia cultivars are frequently a darker green. During the cool shoulder seasons, the timing of dormancy and green-up differs, resulting in a visibly splotchy or uneven lawn.
Controlling Dominance and Maintenance
Managing a mixed lawn requires deciding which species should dominate, as their different maintenance needs make a harmonious balance impossible. Mowing height is a cultural practice that can be leveraged to favor one grass over the other.
Mowing Height
Bermuda grass thrives when mowed short, typically between 0.5 and 1.5 inches, requiring frequent mowing during peak season. Zoysia grass tolerates a higher cut, often maintained between 1 and 2 inches, and its slower growth allows for less frequent mowing. The homeowner must choose a regimen that either stresses Bermuda or allows Zoysia to compete more effectively for sunlight.
Fertilization
Fertilization is another tool for controlling dominance in a mixed stand. Applying high rates of nitrogen fertilizer strongly favors the fast-growing Bermuda grass, encouraging its spread and helping it choke out the Zoysia. Conversely, a lower annual nitrogen application rate is recommended if the goal is to favor Zoysia, due to its naturally lower nutrient requirement.
Herbicide Use
The use of selective herbicides to remove one grass from the other is highly challenging for homeowners because most chemicals injure both species. Specialized selective herbicides, such as those containing fenoxaprop or fluazifop, can suppress Bermuda grass in a Zoysia lawn. However, applying these products often requires professional expertise and may temporarily cause stress or yellowing to the desired Zoysia grass.