Why St. Augustine Grass is Ideal for Florida
When it comes to lush, vibrant lawns in Florida’s warm, humid climate, St. Augustine grass (Stenotaphrum secundatum) is the gold standard. Known for its dense, carpet-like appearance and adaptability to Florida’s diverse environments, it’s the most popular turfgrass choice for homeowners, businesses, HOAs, and landscapers across the state.
This comprehensive guide provides everything you need to know about St. Augustine grass, from its benefits and challenges to detailed cultivar comparisons, establishment methods, and maintenance practices.
What is St. Augustine Grass?
St. Augustine grass is a warm-season turfgrass native to coastal areas of the Gulf of Mexico and Mediterranean. Its dense, spreading growth habit suppresses weeds and protects soil, while its moderate shade and salt tolerance make it particularly suitable for Florida’s coastal and inland regions.
Key Characteristics
- Growth Habit: Creeping, spreading via stolons (above-ground runners).
- Leaf Texture: Medium to coarse blades with a lush blue-green hue.
- Soil Adaptability: Thrives in well-drained soils with a pH range of 5.0–7.5.
- Hardiness Zones: USDA Zones 7–12.
Advantages and Challenges of St. Augustine Grass
Advantages of St. Augustine
- Dense Turf: Provides thick coverage that minimizes weeds and enhances visual appeal.
- Shade Tolerance: Outperforms many other warm-season grasses in shaded areas.
- Salt Tolerance: Ideal for coastal regions with saline conditions.
- Rapid Establishment: Grows quickly when established via sod, plugs, or sprigs.
Challenges of St. Augustine
- High Maintenance: Requires frequent mowing, fertilization, and pest control.
- Poor Wear Tolerance: Struggles under heavy foot or vehicular traffic.
- Thatch Accumulation: Excessive watering and fertilization can lead to thatch buildup.
- Susceptibility to Pests and Diseases: Prone to chinch bugs, gray leaf spot, and other turfgrass issues.
Cultivars of St. Augustine Grass
Selecting the right cultivar of St. Augustine grass is essential for creating a lawn that meets your environmental, aesthetic, and functional needs. Florida offers a range of climates and soil types, and each cultivar brings unique strengths to the table. Here’s an in-depth look at the most popular varieties available for Florida lawns:
Floratam
Floratam is the most widely used St. Augustine grass in Florida, initially developed in 1973 through a collaboration between the University of Florida and Texas A&M University. Known for its vigorous growth and coarse texture, it’s an excellent option for sunny, well-drained areas.
Key Features:
- Growth Habit: Spreads quickly, forming dense coverage that suppresses weeds.
- Pest Resistance: Originally bred for chinch bug resistance, though over time, this resistance has diminished.
- Sun Requirements: Thrives in full sun but struggles in shaded areas, requiring at least 6 hours of direct sunlight daily.
- Disease Susceptibility: Prone to gray leaf spot and large patch, particularly under high moisture and nitrogen conditions.
Specifications:
- Mowing Height: 3.5–4 inches.
- Best Use: Sunny residential or commercial lawns requiring rapid establishment.
- Limitations: Poor performance in shaded areas and susceptibility to certain herbicides, particularly at temperatures above 85°F.
Floratam’s rapid establishment and aggressive growth make it a top choice for large areas where quick coverage is a priority.
BitterBlue
BitterBlue is a classic St. Augustine cultivar known for its dark blue-green color and fine texture. Selected in the 1930s, it remains a versatile and reliable choice for lawns across Florida.
Key Features:
- Shade Tolerance: Performs well in partially shaded areas, though not as shade-tolerant as newer varieties like Palmetto or CitraBlue.
- Cold Tolerance: Suitable for northern Florida due to its resilience in cooler climates.
- Appearance: Its finer texture and dense growth create an attractive, lush lawn.
Specifications:
- Mowing Height: 3.5–4 inches.
- Best Use: Lawns requiring a balance of aesthetics and adaptability in moderate sunlight conditions.
- Limitations: Moderately susceptible to pest infestations and fungal diseases like gray leaf spot.
BitterBlue offers a classic, visually appealing option for homeowners seeking a well-established turfgrass with proven performance.
Raleigh
Raleigh was developed by North Carolina State University in 1980 and is highly regarded for its cold tolerance, making it an excellent choice for northern Florida and areas with cooler winters.
Key Features:
- Cold Tolerance: One of the most cold-hardy St. Augustine varieties, maintaining resilience during frosts and low temperatures.
- Adaptability to Soil Types: Performs well in clay and heavier soils with medium to low pH levels.
- Iron Requirements: May yellow in high summer heat; supplemental iron applications are recommended to maintain its green color.
Specifications:
- Mowing Height: 3.5–4 inches.
- Best Use: Lawns in northern Florida or areas with cooler winters and heavier soils.
- Limitations: Highly susceptible to gray leaf spot and large patch diseases, requiring proactive maintenance.
Raleigh is a go-to option for regions where cold weather is a concern, offering reliable performance with proper nutrient management.
Seville
Seville is a dwarf cultivar that features a finer leaf texture and a lower growth habit, making it a popular choice for ornamental lawns and smaller landscapes.
Key Features:
- Shade Tolerance: Performs well in both full sun and moderate shade, making it suitable for diverse environments.
- Aesthetic Appeal: Its fine-textured blades provide a manicured look, ideal for decorative lawns.
- Cold Sensitivity: Less tolerant of frosty conditions compared to other cultivars.
Specifications:
- Mowing Height: 2–2.5 inches, lower than standard cultivars.
- Best Use: Ornamental landscapes or areas requiring a low-maintenance, visually appealing turf.
- Limitations: Prone to thatch buildup and pest infestations, requiring consistent monitoring and care.
Seville is an excellent option for homeowners prioritizing aesthetics and versatility in shaded or sunlit areas.
Palmetto
Palmetto St. Augustine is widely recognized for its exceptional versatility, resilience, and durability. It has become one of the most popular turfgrasses globally, with over two billion square feet sold.
Key Features:
- Broad Climate Adaptability: Thrives in various climates, from humid coastal regions to inland areas with varying soil types.
- Shade and Drought Tolerance: Its deep root system enables it to withstand shade, heat, and drought effectively.
- Disease Resistance: Demonstrates resistance to Sugarcane Mosaic Virus, a key advantage in disease-prone regions.
Specifications:
- Mowing Height: 1.5–2.5 inches, offering a low-profile aesthetic.
- Best Use: Residential and commercial lawns with mixed sun and shade exposure.
- Limitations: Requires consistent mowing and care to maintain its superior appearance.
Palmetto’s exceptional adaptability and performance make it a top choice for homeowners and landscapers alike.
CitraBlue
Developed by the University of Florida, CitraBlue is a modern cultivar that combines aesthetic appeal with advanced performance features. Its unique deep blue-green color and horizontal growth habit set it apart.
Key Features:
- Disease Resistance: Superior resistance to gray leaf spot, large patch, and take-all root rot compared to other cultivars.
- Reduced Fertilizer Needs: Requires less nitrogen, making it a more sustainable option for Florida landscapes.
- Minimal Maintenance: Lateral growth reduces the need for frequent mowing.
Specifications:
- Mowing Height: 2.5–3.5 inches.
- Best Use: High-traffic areas such as golf courses, sports fields, and residential lawns with children or pets.
- Limitations: Prone to thatch buildup if not carefully managed.
CitraBlue is an excellent choice for those seeking a sustainable, low-maintenance lawn with a distinct and striking appearance.
Making Your Choice
Each St. Augustine grass cultivar offers unique advantages and limitations. Your choice will depend on your property’s specific conditions, such as sunlight, soil type, and intended usage.
Summary of Cultivar Features:
| Cultivar | Shade Tolerance | Drought Tolerance | Cold Tolerance | Maintenance Needs | Appearance |
|---|---|---|---|---|---|
| Floratam | Low | Moderate | Poor | High | Coarse texture |
| BitterBlue | Moderate | Moderate | Moderate | Moderate | Fine texture |
| Raleigh | Low | Moderate | Excellent | High | Medium texture |
| Seville | Moderate | Moderate | Low | Moderate | Fine texture |
| Palmetto | High | Good | Good | Moderate | Medium texture |
| CitraBlue | High | Very Good | Good | Low | Deep blue-green |
Establishing St. Augustine Grass
St. Augustine grass is established vegetatively, as it does not produce viable seeds. This means it must be planted using sod, sprigs, or plugs. The choice of method depends on factors such as budget, time constraints, and desired coverage speed. No matter the method, proper site preparation is essential for successful establishment. This includes soil testing, grading, and removal of debris or existing vegetation.
For more details on site preparation and establishment, consult UF/IFAS’s Preparing to Plant a Florida Lawn.
Sodding St. Augustine Lawn
Sod installation is the fastest and most effective method for establishing St. Augustine grass. It provides immediate coverage, reduces soil erosion, and suppresses weed growth. While the upfront cost is higher than other methods, its rapid results make it an ideal choice for most Florida lawns.
Steps to Establish a Lawn with Sod
- Soil Preparation:
- Remove all existing grass and weeds.
- Grade the soil to ensure proper drainage.
- Perform a soil test to confirm a pH between 5.0 and 7.5, amending as needed.
- Lay Sod:
- Arrange sod pieces in a staggered, brick-like pattern to minimize gaps.
- Press the edges tightly together to prevent weed intrusion.
- Roll the Lawn:
- Use a lawn roller to press the sod firmly into the soil, ensuring optimal root contact.
- Water Thoroughly:
- Apply enough water to moisten the soil to a depth of 6–8 inches immediately after installation.
Irrigation Schedule for Newly Sodded Lawns:
- Water multiple times daily for the first 7–10 days to keep the topsoil consistently moist.
- Gradually reduce watering frequency over the next few weeks.
For detailed irrigation guidelines, refer to Watering Your Florida Lawn.
Sprigging and Plugging a St. Augustine Lawn
Sprigging and plugging are cost-effective methods for establishing St. Augustine grass, though they require more time to achieve full coverage.
Sprigging
- Spread sprigs end-to-end in furrows 6–12 inches apart.
- Lightly cover the sprigs with soil, ensuring leaf blades remain exposed.
- Keep the soil consistently moist until the sprigs root and stolons begin spreading.
Plugging
- Plant plugs (small sections of sod) at intervals of 6–24 inches.
- Closer spacing results in faster coverage but increases initial labor.
- Follow a similar watering schedule to that for sodding.
For more information on sprigging and plugging, refer to Establishing Your Florida Lawn.
Maintain Your St. Augustine Lawn
Proper maintenance is crucial to ensuring the health and longevity of a St. Augustine grass lawn. A consistent focus on mowing, watering, fertilizing, and pest management will keep your lawn vibrant and resilient year-round.
Mowing
Mowing is one of the most important cultural practices for maintaining a healthy lawn. Correct mowing height and frequency encourage deep rooting, reduce weed invasion, and minimize stress on the grass.
Best Practices:
- Mowing Heights:
- Standard cultivars (e.g., Floratam, BitterBlue): 3.5–4 inches.
- Dwarf cultivars (e.g., Seville): 2–2.5 inches.
- Frequency:
- Weekly during the active growing season (spring and summer).
- Less frequently during cooler months or periods of dormancy.
- Mower Blade Maintenance:
- Use sharp blades to ensure clean cuts and avoid tearing the grass.
- Check blade sharpness regularly during the growing season.
For more detailed mowing recommendations, visit Mowing Your Florida Lawn.
Watering
Watering your St. Augustine grass correctly is essential to maintaining its health and appearance while conserving water. Overwatering can lead to disease and shallow rooting, while under-watering can cause drought stress.
When to Water:
- Look for signs of drought stress:
- Leaf blades fold lengthwise or turn bluish-gray.
- Footprints remain visible after walking on the lawn.
Application Guidelines:
- Apply ½–¾ inch of water per irrigation session.
- Water deeply and infrequently to encourage deep rooting.
Seasonal Adjustments:
- Water more frequently during periods of high heat and less frequently in cooler months.
- Follow local watering restrictions to ensure compliance with conservation laws.
For a guide to efficient irrigation practices, see UF/IFAS Lawn Watering Guide.
Fertilizing
Proper fertilization is key to promoting healthy growth and resilience in St. Augustine grass. However, over-fertilization can lead to excessive thatch and increased susceptibility to pests and diseases.
Fertilization Guidelines:
- Frequency:
- Apply nitrogen-rich fertilizer 2–6 times annually, depending on region and lawn conditions.
- Fertilize during active growth periods (spring through early fall).
- Soil Testing:
- Test soil pH and nutrient levels before fertilizing.
- Use slow-release nitrogen products to minimize nutrient runoff.
- Regional Rates:
- Northern Florida: 2–4 pounds of nitrogen per 1,000 square feet annually.
- Central Florida: 3–5 pounds of nitrogen per 1,000 square feet annually.
- Southern Florida: 4–6 pounds of nitrogen per 1,000 square feet annually.
For a complete guide to fertilization practices, consult the Florida-Friendly Landscaping Program.
Pest and Disease Management
St. Augustine grass is vulnerable to pests and diseases that can cause significant damage if not managed proactively.
Common Pests:
- Southern Chinch Bugs:
- Symptoms include yellowing or browning patches in sunny areas.
- Check for chinch bugs using a flotation method, such as a coffee can filled with water.
- Mole Crickets:
- Tunneling activity causes soil disruption and thinning turf.
- Use soapy water (1½ oz. dish soap per gallon of water) to flush out mole crickets.
- White Grubs:
- Grubs feed on roots, causing thinning and spongy turf.
Common Diseases:
Gray Leaf Spot
- Symptoms: Brown or gray lesions on leaf blades, often with a water-soaked appearance.
- Conditions: Thrives in warm, humid weather and is exacerbated by excessive nitrogen application.
- Prevention and Control:
- Avoid applying soluble nitrogen fertilizers during peak summer months.
- Water early in the morning to allow leaf blades to dry quickly.
- Use fungicides labeled for gray leaf spot if necessary.
Large Patch (Rhizoctonia Solani)
- Symptoms: Circular, discolored patches of grass, often with a yellow to orange border, appearing in cool, wet conditions.
- Conditions: Most common during the spring and fall when temperatures range from 60–75°F.
- Prevention and Control:
- Improve soil drainage by aerating compacted areas.
- Reduce irrigation during cool weather to prevent prolonged leaf wetness.
- Apply fungicides as a preventive measure during periods of high disease pressure.
Brown Patch
- Symptoms: Circular or irregular patches of brown grass that enlarge over time. The affected grass blades may have dark, water-soaked lesions with a distinct brown border.
- Conditions: Common during warm days (70–90°F) and cool nights with high humidity or prolonged leaf wetness.
- Prevention and Control:
- Avoid excessive nitrogen fertilization in late summer and early fall.
- Irrigate early in the morning to allow grass to dry during the day.
- Keep mowing heights at the recommended level to reduce stress on the grass.
- Use fungicides labeled for large patch if cultural controls are insufficient.
Management Strategies:
- Follow Integrated Pest Management (IPM) techniques, combining cultural, biological, and chemical controls.
- Use fungicides and insecticides as necessary, following label instructions and local regulations.
For pest-specific recommendations, refer to UF/IFAS Turfgrass Pest Management Guide.
Conclusion
St. Augustine grass is a versatile and beautiful option for Florida landscapes, offering aesthetic appeal and resilience in the state’s unique climate. By selecting the right cultivar and adhering to best practices in establishment and maintenance, you can enjoy a thriving lawn year-round.
For additional guidance or personalized advice, consult your local UF/IFAS Extension office. Whether you’re a homeowner, landscaper, or property manager, St. Augustine grass remains a reliable choice to enhance any property.