Grasses

Stenotaphrum secundatum

St. Augustine Grass

Poaceae

Gulf of Mexico / Caribbean / coastal tropical-subtropical Americas and Africa (S. secundatum; Gulf Coast standard; coarsest lawn; most shade-tolerant warm-season; stoloniferous; z8-10)

At a Glance

TypeGrass
HabitSpreading
FoliageEvergreen
Height6-12 inches (15-30 cm) unmowed; 3-4 inches (8-10 cm) mowed
WidthIndefinite via stolons
Maturity1 years

Growing Zones

USDA Hardiness Zones

8 - 10
Zone 8
Zone 9
Zone 10
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancetender

Key Features

Native to North America
Maintenancehigh

Overview

Stenotaphrum secundatum is a warm-season perennial stoloniferous grass reaching 6-12 inches (15-30 cm) tall (unmowed) with an aggressive, indefinite spread via thick, fleshy, above-ground stolons and a dense, coarse-textured turf habit. Native to the Gulf of Mexico, Caribbean, and coastal tropical/subtropical regions, it forms a thick, spongy, medium to dark green lawn with broad, flat blades 4-8 mm wide—the coarsest of common lawn grasses. Maintained at mowing heights of 3-4 inches (8-10 cm). Established exclusively by sod, plugs, or sprigs—does not produce viable seed in commercial quantities. The dominant warm-season lawn grass of the Gulf Coast states, Florida, and coastal Southeast. Shade-tolerant—the most shade-tolerant warm-season grass, maintaining turf in 4-6 hours of sun where bermudagrass and zoysiagrass fail.

Native Range

Stenotaphrum secundatum is native to the Gulf of Mexico, Caribbean, and coastal tropical and subtropical regions of the Americas and Africa.

Suggested Uses

Used in home lawns, parks, and commercial landscapes throughout the Gulf Coast, Florida, and coastal Southeast. Most shade-tolerant warm-season grass. Dense coarse spongy turf. Thick stolons—good erosion control. Salt-tolerant—coastal sites. Warm-season z8-10. Not suitable for northern climates (no cold tolerance), fine-textured lawns (coarsest grass), or high-traffic sports turf (poor wear tolerance). No seed—sod/plugs/sprigs only.

How to Identify

Distinguished from zoysiagrass (Zoysia japonica) by the broader coarser blades (4-8 versus 2-4 mm), the stoloniferous (versus both stoloniferous and rhizomatous) spread, the greater shade tolerance, and the less cold-tolerant range (z8-10 versus z6-9). Distinguished from bermudagrass (Cynodon dactylon) by the broader coarser blades, the shade tolerance, and the stolons-only (versus stolons and rhizomes) spread. St. Augustine—coarsest lawn grass, most shade-tolerant warm-season, stoloniferous, Gulf Coast standard, sod/plugs only.

Appearance

Size & Dimensions

Height3" - 1'
Width/Spread1' - 2'

Reaches mature size in approximately 1 years

Colors

Flower Colors

green

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~4 weeks
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Summer
Short, branching inflorescences embedded in flattened, one-sided racemes in summer if unmowed. Generally inconspicuous. Produces little viable seed—propagated vegetatively.

Detailed Descriptions

Flower Description

Green; inconspicuous flattened racemes; summer if unmowed

Foliage Description

Medium to dark green; broad flat coarse blades 4-8 mm; thick fleshy stolons

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)
357912
Soil Types
loamsandclay
Drainage
well drained

Water & Climate

Water Needs

High

Frost Tolerance

tender

Time to Maturity

Full coverage from plugs in one growing season

Care & Maintenance

Care Guide

Establish by sod, plugs (12-inch spacing), or sprigs in late spring to summer when soil is warm. Full sun to moderate shade (4-6 hours minimum). Fertile, moist, well-drained soil (pH 6.0-7.5). Mow at 3-4 inches with a sharp rotary mower. Water 1 inch per week. Fertilize 2-4 lb nitrogen per 1,000 sq ft per year. Warm-season—browns in winter dormancy below 55°F (13°C). Susceptible to chinch bugs, gray leaf spot, and SAD virus. Builds thatch—dethatch as needed.

Pruning

Mow at 3-4 inches (8-10 cm) with a sharp rotary mower (too coarse for reel mowers). Never remove more than one-third of blade height. Mow higher in shade.

Pruning Schedule

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late springsummerfall

Maintenance Level

high

⚠️ Toxicity Warning

Non-toxic