Stenotaphrum spp.

St. Augustine Grass

Poaceae

Tropical and subtropical coasts worldwide

Drought Tolerant Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 8–11

Overview

Stenotaphrum spp. is a genus of about seven warm-season grasses in the family Poaceae, found on tropical and subtropical coasts around the world. The plants are creeping, stoloniferous perennials that root at the nodes to form dense mats, with blunt-tipped, flattened blades 0.2-0.6 inch (4-15 mm) wide. The most cultivated species, S. secundatum, is grown widely as St. Augustine grass, a coarse warm-climate lawn turf. Flowering stems rise 4-12 inches (10-30 cm) above the mat and carry a flattened, spike-like inflorescence in which the spikelets are partly sunk into a thickened, corky axis. Stenotaphrum spp. spreads vigorously by surface runners and tolerates salt spray, sandy soils, and coastal exposure, but is sensitive to hard frost and turns brown below about 55 F (13 C). It grows in full sun to moderate shade, more shade-tolerant than many warm-season turf grasses. Mat-forming growth can overrun bed edges and needs containment. Across the genus the grasses occupy dunes, coastal flats, and disturbed ground in frost-free to mild climates, and several are used for lawns, erosion control, and pasture.

Native Range

Stenotaphrum spp. occurs on tropical and subtropical coasts worldwide, including the Americas, Africa, Asia, and Pacific and Indian Ocean islands. S. secundatum is native to coastal regions of the Gulf of Mexico, the Caribbean, and warm parts of Africa. Typical habitats are sandy shores, dunes, and coastal flats.

Suggested Uses

Stenotaphrum spp. is used as warm-season lawn turf, for coastal erosion control, and for ground stabilization on sandy and saline sites. Its salt tolerance suits seaside gardens and dune plantings. Some forms with variegated blades are grown as trailing container and groundcover plants.

How to Identify

Identify Stenotaphrum spp. by its creeping, stoloniferous mat of blunt, flattened blades 0.2-0.6 inch (4-15 mm) wide that root at the nodes. The clearest feature is the flattened, spike-like flowering stem, where short-stalked spikelets are embedded in shallow pits along a thickened, corky axis. Coastal habitat and broad, soft runners help separate it from narrow-leaved turf grasses.

Appearance

Size & Dimensions

Height4" - 1'

Width/Spread2' - 10'

Colors

Flower Colors

green

tan

Foliage Colors

green

Bloom Information

Bloom Period

~8 weeks

Summer Fall

Flowering occurs mainly in summer and early autumn in warm climates, and almost year-round in frost-free tropics. The flattened seed heads are inconspicuous against the foliage. Many cultivated forms are propagated from runners and flower sparingly.

Detailed Descriptions

Flower Description

green to tan

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-12 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 Range5.0 - 8.5(Neutral)

357912

Soil Types

sand loam

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

1 year

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Stenotaphrum spp. grows in full sun to moderate shade and tolerates a wide range of soils, including sandy and saline coastal ground. Water needs are medium; established mats withstand short drought but brown out in long dry spells. It performs in soil pH from about 5.0 to 8.5 and recovers quickly from wear by spreading runners. Growth slows and color fades below roughly 55 F (13 C), and hard frost damages or kills top growth, limiting it to USDA zones 8-11. The grass spreads aggressively and can invade borders and paths. Thatch builds up in vigorous stands and is managed by periodic dethatching.

Pruning

Maintenance is by mowing rather than pruning, kept at 2.5-4 inches (6-10 cm) for lawn use. Runners that creep into beds and paths are trimmed back along edges. Thick thatch is removed periodically to keep the mat healthy.