St. Augustine Grass care — light, water, toxicity and hardiness
St. Augustine Grass (Stenotaphrum secundatum) wants full sun and a drink about every 4 days once established. It is hardy in USDA zones 8 to 10. It is safe to have around pets.
| scientific name | Stenotaphrum secundatum |
|---|---|
| family | Poaceae |
| category | grass |
| plant type | perennial |
| light | full sun |
| water cadence days | 4 |
| mature height cm | 10 |
| min zone | 8 |
| max zone | 10 |
| frost tolerant | false |
| toxic to pets | false |
| toxic to humans | false |
| edible | false |
How often should I water St. Augustine Grass?
Shade-tolerant warm-season lawn; chinch bugs.
Who eats it
Palatable to browsing animals such as deer: low. Palatable to grazing animals: medium. Palatable to people: no.
What it needs
Its shade tolerance is medium. Its moisture use is medium. Its drought tolerance is medium. It wants at least about 40 inches of rain a year. Above roughly 60 inches of annual rain it struggles. It tolerates soil down to pH 6.5. It tolerates soil up to pH 7.5. Its fertility requirement is medium. Adapted to coarse, sandy soils: no. Adapted to medium, loamy soils: yes. Adapted to fine, clay soils: yes. It needs at least 230 frost-free days. Its salt tolerance is high. Its tolerance of chalky soil is medium. Its fire tolerance is medium. Fire resistant: yes. It has been recorded down to 2°F. It suppresses neighbours chemically: no.
How it grows
It grows as a rhizomatous form. Its growth rate is rapid. Its lifespan is short. It puts on most of its growth in summer and fall. It spreads vegetatively at a rapid rate. It resprouts after damage: no. Coppices: no. At maturity it reaches about 0.9 feet. Its roots go down at least 18 inches. Its shape is prostrate. It holds its leaves through winter: no.
What it looks like
Conspicuous in flower: no. The foliage is green. The foliage texture is fine. In summer the canopy is porous in porosity. In winter it is porous in porosity. Fall colour: no. The fruit persists on the plant: no. The fruit is conspicuous: no.
Growing more of it
Propagated by seed: no. Propagated by cuttings: no. Propagated by container: no. Propagated by bare root: no. Propagated by bulb: no. Propagated by corm: no. Propagated by tubers: no. Cold stratification required: no. Seedling vigour is low. Commercial availability: routinely available.
Source: Drafted from US Cooperative Extension horticulture guidance; pending HUMAN-05 review (issue 280) · ASPCA Toxic and Non-Toxic Plant List · 2026-09-02