Zoysia and Bermuda grasses are popular warm-season turf varieties that thrive in similar climates, but intentionally mixing them in a lawn is generally not recommended. These grasses are genetically distinct and possess different growth habits, leading to significant challenges in maintaining a uniform and healthy appearance. Homeowners often consider mixing them to combine desirable traits, such as Zoysia’s density and Bermuda’s resilience, but the resulting competition usually defeats this purpose.
Understanding Zoysia and Bermuda Grasses
Zoysia and Bermuda grasses exhibit distinct characteristics that govern their performance and maintenance requirements. Zoysia grass is recognized for its dense, carpet-like growth habit, spreading relatively slowly via both underground rhizomes and above-ground stolons. This growth creates a thick turf that naturally suppresses weeds. Its blades are typically medium to coarse in texture, ranging from 2 to 7 millimeters in width, and the grass maintains a deep, rich green color. Zoysia also shows a better tolerance for moderate shade compared to Bermuda grass.
Bermuda grass is known for its aggressive and rapid growth, utilizing both rhizomes and stolons to spread quickly and recover from damage. It features finer blades, usually under 1.7 millimeters wide, which contributes to the tight appearance often seen on golf courses. Bermuda grass requires full, direct sun for at least six to eight hours a day to thrive. It also prefers a higher nitrogen fertilization rate to support its vigorous growth.
The Competition: Results of Combining Zoysia and Bermuda
The primary outcome of combining these two grasses is a patchy, non-uniform lawn due to their competitive nature. Bermuda grass is significantly more aggressive and has a much faster growth rate than Zoysia, allowing it to rapidly colonize and invade Zoysia areas. The resulting turf often displays an undesirable mottled appearance because of the stark contrast in blade texture and color. Bermuda’s finer blades and brighter green color clash visually with Zoysia’s wider blades and deeper green hue.
In most scenarios, the fast-spreading Bermuda grass will dominate the slower-growing Zoysia. This is especially true under high-maintenance regimes that include frequent watering and high nitrogen fertilization, which heavily favor Bermuda’s rapid growth cycle. Zoysia might hold its own or even slightly outcompete Bermuda in areas with partial shade, as Bermuda requires full sun to maintain its density. However, the overall effect is a loss of turf consistency and an uneven lawn surface.
Strategies for Dealing with a Mixed Turf
Managing a lawn that contains a mix of Zoysia and Bermuda grass is challenging due to their differing maintenance requirements.
Mowing Challenges
Mowing presents a difficulty because Bermuda often requires a lower cutting height, around 0.5 to 1.5 inches, while Zoysia is usually maintained slightly higher, often between 1 and 2 inches. Attempting to satisfy both grasses simultaneously often results in one species being stressed or scalped, further exacerbating the competitive imbalance. The different textures of the blades can also make the lawn feel inconsistent underfoot.
Chemical Control
Chemical control is difficult because both are warm-season grasses, limiting the number of selective herbicides that can target one without harming the other. Products used to control Bermuda, such as those containing fenoxaprop or fluazifop, can injure Zoysia, causing yellowing and a temporary reduction in quality. Recent advancements, such as combining herbicides like Fusilade II with a safener like Recognition, have made it possible to suppress Bermuda in Zoysia. However, this process is complex and often requires multiple, carefully timed applications.
Management Approaches
For homeowners faced with a mixed lawn, there are two primary management approaches: aggressive favoring or total renovation. The aggressive favoring strategy involves intentionally adjusting cultural practices, such as applying high nitrogen fertilizer, to promote the dominance of one desired species. The more definitive solution is a total renovation, which requires killing the entire mixed turf with a non-selective herbicide like glyphosate. After removing the dead vegetation, the area is replanted with a single, preferred grass variety.