St. Augustine grass is a warm-season turfgrass common in the warm, humid regions of the Southeast United States. It is characterized by broad, flat leaf blades and a dense, carpet-like growth pattern achieved through above-ground runners called stolons. Homeowners often seek alternatives to match this lush, coarse texture or to find a grass that performs better under specific environmental challenges. While no single grass perfectly replicates the St. Augustine look, several warm-season varieties come close or excel in certain areas. Finding a suitable replacement depends on prioritizing visual aesthetics or better resistance to shade, cold, or drought conditions.
Grasses That Mimic Appearance and Texture
The most recognizable feature of St. Augustine grass is its coarse texture and wide blade, often having a blunt tip. Alternatives that attempt to match this look usually fall into the medium-to-coarse-bladed categories of other warm-season grasses. Centipede grass and certain Zoysia cultivars are the two main contenders for visual similarity.
Centipede grass has a similar coarse texture to St. Augustine, but its leaf blades are noticeably narrower and often have a distinct crease, appearing somewhat folded. St. Augustine blades are typically twice as wide and possess a flatter appearance with a more blunt tip. Centipede grass also displays a lighter, yellowish-green hue compared to the rich, often bluish-green tint of St. Augustine.
Zoysia grass offers a wide range of cultivars, allowing for a closer match in texture. Finer-bladed Zoysia types, such as Emerald Zoysia, look much different than St. Augustine. However, medium-to-coarse varieties, such as Zoysia matrella types, can bridge the visual gap. Selecting a cultivar with a wider leaf blade helps mimic the substantial look of St. Augustine.
Bahia grass is another common alternative, but its appearance is generally considered less desirable for a manicured lawn. The blades of Bahia grass are relatively thin and taper to a point, lacking the substantial blunt tip of St. Augustine. Bahia grass also produces tall, V-shaped seed heads that require frequent mowing to control.
Comparing Climate and Environmental Tolerance
The primary motivation for seeking an alternative to St. Augustine grass is its vulnerability to environmental stressors, particularly cold and drought. St. Augustine has moderate drought tolerance and low cold tolerance, making it suitable for frost-free or mildly-freezing regions. Its strength is its ability to handle partial shade better than most other warm-season grasses.
For better cold tolerance, certain varieties of Zoysia grass and Bermuda grass are superior choices. St. Augustine suffers damage below 25 degrees Fahrenheit. Centipede grass can handle below-freezing temperatures, and Bermuda grass generally survives further north. Some Zoysia cultivars exhibit significantly improved cold hardiness, allowing them to be grown in transition zones.
When drought is the primary concern, Bermuda grass and Bahia grass significantly outperform St. Augustine. Bermuda grass is known for its excellent drought resistance due to its aggressive growth and deep root system, allowing quick recovery from dry periods. Bahia grass is highly drought-tolerant and requires minimal water once established. St. Augustine requires supplemental irrigation during extended dry periods.
Shade tolerance is a major advantage of St. Augustine, which performs well receiving four to six hours of sunlight daily. Most varieties are more shade-tolerant than Centipede and Bermuda grass, which require six or more hours of direct sun to thrive. St. Augustine is typically the best choice among warm-season grasses for lawns with mature trees or partial shade.
Differences in Ongoing Turf Management
The ongoing care required for St. Augustine differs significantly from its alternatives, particularly concerning mowing height and nutrient demands. St. Augustine grass requires a high mowing height, typically between three and four inches, to maintain health and density. Mowing it too short can severely damage the turf.
Bermuda grass thrives when mowed much shorter, ideally between one and two inches, to achieve a dense, high-quality turf. Zoysia grass is more flexible; some varieties perform well at lower cuts similar to Bermuda, while coarser types require a higher cut. Centipede grass is known for its low maintenance needs, including a low mowing height of one to two inches.
Fertilization requirements represent a substantial difference. St. Augustine and Bermuda grass are considered high-maintenance in terms of nutrient needs, requiring more nitrogen to maintain their lush appearance. St. Augustine requires a high level of fertilization, generally between three and six pounds of nitrogen per 1,000 square feet annually. Centipede grass is highly sensitive to excessive fertilizer and requires a significantly lower annual nitrogen application.
Pest and disease susceptibility also influence management strategies. St. Augustine is notably prone to chinch bug infestations, which cause significant damage if not treated. It is also sensitive to many common herbicides, which limits weed control options. Bermuda grass is highly resistant to foot traffic, but its aggressive nature often requires frequent edging and more intensive weed management.