Your Guide to St. Augustine Grass

St. Augustine grass (Stenotaphrum secundatum) is a warm-season turfgrass that is highly valued for its lush appearance and ability to create a dense, carpet-like lawn. It’s a popular choice for homeowners in Texas due to its adaptability to the state’s warm climate and varying soil conditions. Here are its key characteristics:

Characteristics of St. Augustine Grass

01. Color: Rich Medium to Dark Green

• Visual Appeal: St. Augustine grass provides a vibrant, medium to dark green hue that adds a rich aesthetic to residential and commercial landscapes. This deep coloration remains consistent throughout the growing season, enhancing curb appeal.
• Seasonal Color Retention: It maintains its color well into the fall, providing an extended period of greenery compared to other warm-season grasses.

02. Blade Width: 8–9 mm

• Texture: With blades measuring between 8 to 9 millimeters in width, St. Augustine grass has one of the widest blades among warm-season grasses. This contributes to its coarse texture, giving lawns a thick and luxurious feel.
• Comfort: The broad blades offer a soft cushion underfoot, making it comfortable for outdoor activities and ideal for families with children and pets.

03. Growth Habit: Spreads via Above-Ground Stolons (Runners)

• Propagation: St. Augustine grass spreads horizontally through stolons, which are above-ground stems that creep along the soil surface. These stolons root at nodes to form new plants, allowing the grass to fill in bare spots effectively.
• Erosion Control: The dense network of stolons helps stabilize soil, reducing erosion on slopes and uneven terrains.

04. Shade Tolerance: Moderate

• Adaptability to Light Conditions: St. Augustine grass can tolerate partial shade, performing better in shaded areas than Bermuda grass but not as well as some Zoysia varieties. It requires at least 4 to 6 hours of sunlight daily.
• Ideal Environments: Suitable for lawns with a mix of sun and shade, such as areas under tree canopies or next to buildings that block sunlight during part of the day.

05. Drought Tolerance: Moderate; Requires Consistent Moisture

• Water Needs: While it can withstand short periods of drought by entering dormancy, St. Augustine grass prefers consistent moisture to maintain its lush appearance.
• Irrigation Practices: Regular watering during dry spells is essential. Deep, infrequent watering encourages deeper root growth, improving drought resistance over time.

06. Salt Tolerance: High; Suitable for Coastal Areas

• Coastal Resilience: St. Augustine grass thrives in saline environments, making it an excellent choice for coastal regions where salt spray and salty soils can inhibit the growth of other grass types.
• Soil Versatility: Performs well in a variety of soil types, including sandy soils commonly found near coastlines.

Popular Varieties of St. Augustine Grass

Over the years, turfgrass breeders have developed several varieties of St. Augustine grass to enhance specific traits such as shade tolerance, cold tolerance, and disease resistance. Understanding the differences between these varieties helps homeowners select the best option for their specific needs.

1. Floratam

Floratam was developed in 1973 through a collaborative effort between the University of Florida and Texas A&M University. The name “Floratam” is a portmanteau of Florida and Texas A&M, reflecting its joint development. Bred specifically to be resistant to the St. Augustine Decline (SAD) virus and the southern chinch bug (Blissus insularis), which were causing significant damage to St. Augustine lawns during that period.

• Development History:
  • Created in 1973 through a collaborative effort between the University of Florida and Texas A&M University.
  • Bred to be resistant to the St. Augustine Decline (SAD) virus and chinch bugs.
• Characteristics:
  • Vigorous Growth: Exhibits rapid growth and robust spreading habit, allowing it to establish quickly.
  • Coarse Texture: Has larger and coarser blades compared to other varieties, giving it a distinctive appearance.
  • Drought Tolerance: Demonstrates better drought resistance due to its deep root system, reducing water requirements.
• Usage:
  • Sun Requirements: Thrives in full sun and does not perform well in shaded areas.
  • Popularity: The most widely planted St. Augustine variety in Texas, especially in Central and South Texas regions.

2. Raleigh

Found in Raleigh, North Carolina, and introduced to the market in 1980. Chosen for its improved cold tolerance and adaptability to cooler climates compared to other St. Augustine varieties.

• Origin:
  • Discovered in Raleigh, North Carolina, and introduced in 1980.
  • Selected for its improved cold tolerance.
• Characteristics:
  • Cold Tolerance: Better suited for cooler climates, surviving temperatures that would damage other St. Augustine varieties.
  • Medium Texture: Blades are slightly finer than Floratam, providing a softer feel.
  • Color: Maintains a medium to dark green color throughout the growing season.
• Usage:
  • Adaptability: Performs well in both sun and partial shade.
  • Ideal Regions: Recommended for North Texas and areas prone to cooler temperatures and occasional frost.

3. Palmetto

Found in Florida in the early 1990s by sod grower Everett Conner. Patented in 1994, making it one of the newer St. Augustine varieties on the market.

• Development:
  • Discovered in Florida in the early 1990s and selected for its superior qualities.
  • Patented in 1994, making it a relatively new variety.
• Characteristics:
  • Shade Tolerance: Exhibits enhanced shade tolerance, performing well in areas with limited sunlight.
  • Finer Texture: Blades are finer and softer, creating a more delicate appearance and feel.
  • Color Retention: Retains color longer into the cooler months compared to other varieties.
• Usage:
  • Versatility: Suitable for lawns with a mix of sun and shade.
  • Maintenance: Slower growth rate reduces mowing frequency, making it a low-maintenance option.

4. Delmar

Exhibits slower vertical growth, resulting in less frequent mowing requirements. It provides a neat, manicured look with minimal effort.

• Known For:
  • Its dwarf growth habit and slower vertical growth rate.
• Characteristics:
  • Shade Tolerance: Performs exceptionally well in shaded environments, retaining density and color.
  • Slower Growth: Requires less frequent mowing due to reduced vertical growth.
  • Fine Texture: Has a finer leaf blade, providing a soft, plush lawn surface.
• Usage:
  • Ideal For: Areas with significant shade coverage, such as properties with mature trees.
  • Maintenance: Lower maintenance needs make it appealing for homeowners seeking less intensive lawn care routines.

Climate Suitability of St. Augustine Grass

Texas’s diverse climate zones require careful selection of turfgrass to ensure optimal performance. St. Augustine grass’s adaptability makes it a suitable choice for many regions across the state.

USDA Hardiness Zones 8–10

• Zone 8 (North Texas):
  • Experiences hot summers and cool winters with occasional frost.
  • Recommendation: Use cold-tolerant varieties like Raleigh to withstand lower temperatures.
• Zone 9 (Central Texas):
  • Characterized by hot summers and mild winters.
  • Recommendation: Most St. Augustine varieties, including Floratam and Palmetto, perform well here.
• Zone 10 (South Texas):
  • Features very hot summers and very mild winters with rare frost.
  • Recommendation: Heat-tolerant varieties like Floratam are ideal for these conditions.

Regional Recommendations:

• North Texas (Dallas-Fort Worth):
  • Challenges: Greater temperature fluctuations and risk of winter damage.
  • Grass Selection: Raleigh is preferred for its resilience to cooler temperatures and ability to recover from frost damage.
• Central Texas (Austin):
  • Climate: Consistent warmth with ample rainfall.
  • Grass Selection: Homeowners have flexibility; Floratam, Palmetto, and Raleigh all perform well.
• South Texas (Houston, San Antonio):
  • Climate: High humidity and intense heat.
  • Grass Selection: Floratam excels due to its heat tolerance and robust growth in full sun conditions.

Homeowners often choose St. Augustine for its shade tolerance and lower maintenance compared to Bermuda grass, especially in residential areas with trees and landscaping features that create shaded environments.

Prevalence of St. Augustine Grass in Texas Lawns

Coverage: St. Augustine grass accounts for approximately 30% of home lawns in Texas, according to the Texas Cooperative Extension.

Popularity: Its widespread use is attributed to its attractive appearance and adaptability to the state’s climate and soil conditions.

Ranking Among Turfgrasses: St. Augustine grass is the second most popular turfgrass in Texas, following Bermuda grass.