St. Augustinegrass

What is St. Augustinegrass?

St. Augustinegrass (Stenotaphrum secundatum) is a warm-season lawn grass that spreads by thick runners on the soil surface. It has the coarsest leaves of the warm-season lawn grasses, and it forms a dense, green to blue-green turf.

It is not grown from seed. Lawns go in as sod, plugs or sprigs. UF/IFAS covers cultivars such as Floratam, Palmetto, Raleigh, CitraBlue, ProVista, BitterBlue and the dwarf Seville. They differ in shade, cold and chinch bug tolerance, so the cultivar matters as much as the species.

This is a southern grass. NC State says cold is the main thing limiting its use even in North Carolina. For grasses that fit Pennsylvania, see our Pennsylvania grass seed guide.

How to identify St. Augustinegrass

Pull up a few shoots and look closely where the leaf blade meets the stem. Here is what to check on St. Augustinegrass:

• Vernation: Folded in the bud.
• Ligule: A short fringe of hairs, about 0.3 mm (0.01 in.) long; sometimes just a few hairs.
• Auricles: None.
• Collar: Continuous, hairless, pinched in and twisted.
• Leaf blade: 4 to 10 mm wide, V-shaped in cross section, with a blunt, boat-shaped, hairless tip.
• Sheath: Open and flattened; slightly hairy along the edges and toward the top.
• Seedhead: A thick spike with the spikelets sunk into its sides.
• Growth habit: Stout stolons only; no rhizomes.

Where St. Augustinegrass is grown in the US

St. Augustinegrass is a lawn grass of warm, humid places without long cold spells. UF/IFAS rates it adapted statewide in Florida, on most soils from acidic to mildly alkaline.

NC State calls it the least cold-tolerant warm-season grass, and cold is the main thing limiting its use in North Carolina. Oklahoma State limits it to the far south of that state and to sheltered sites.

Homeowners pick it for its thick, broad-bladed look and because some cultivars handle shade better than other warm-season grasses. It is a poor choice for play areas, since it does not stand up to heavy traffic.

St. Augustinegrass pros and cons

Pros

• Dense, green to blue-green turf
• Some cultivars tolerate shade better than other warm-season grasses
• Good salt tolerance
• Establishes quickly from sod
• Fits most Florida soils, acidic to mildly alkaline

Cons

• Poor wear tolerance
• Least cold-tolerant warm-season lawn grass
• No seed; sod, plugs or sprigs only
• Needs water to stay green in long dry spells
• Southern chinch bug is a major pest
• Builds thatch under heavy feeding and watering
• Grassy weeds are hard to control in it

Grasses that look like St. Augustinegrass

How and when to plant St. Augustinegrass

Ways to plant: Sod, plugs or sprigs. Not grown from seed.

Seeding rate: Not sold as seed. Plugs 6 to 24 in. apart; sprigs end to end in furrows 6 to 12 in. apart (UF/IFAS).

Germination: No seed. Sod roots in and is fully established in about 3 to 4 weeks with proper watering (UF/IFAS).

When to plant: Year-round in warm areas. In south Florida, late fall, winter or spring is best. In central and north Florida, avoid cold winters and hot, dry summers (UF/IFAS).

Seeding dates change from state to state. See when to plant grass seed by state, or our Pennsylvania grass seed guide if you are in PA.

How to care for St. Augustinegrass

Mowing: Mow standard cultivars at 3.5 to 4 in. and dwarf cultivars at 2 to 2.5 in. Never remove more than one-third of the blade at a time. UF research found robotic mowers can hold Floratam at about 2.4 in. because they cut a little very often.

Watering: Water established lawns when blades fold, wilt, turn blue-gray or hold footprints, putting down 1/2 to 3/4 in. each time. New sod: several 5 to 10 minute waterings a day for 7 to 10 days, then once a day at 1/4 to 1/2 in., then 2 to 3 times a week (UF/IFAS).

Fertilizing: Follow UF/IFAS regional totals (2 to 6 lb N per 1,000 sq ft per year) split over the season. Florida rules cap single feedings; no more than 0.7 lb of quick-release N at once. Too much nitrogen and water feeds thatch and large patch.

Nitrogen per year: 2 to 4 lb (north Florida), 2 to 5 lb (central) and 4 to 6 lb (south) N per 1,000 sq ft per year, split into 2 to 6 feedings (UF/IFAS).

Overseeding: Not grown from seed. Patch thin spots with plugs or sod. UF/IFAS suggests 2-in. plugs every 12 in. or broadcast sprigs at 1 bushel per 1,000 sq ft when renovating.

Thatch: Builds up under heavy feeding and watering. If thatch passes 1 in., verticut in early spring to midsummer while the grass is growing (UF/IFAS).

Common St. Augustinegrass problems

If a pesticide is needed, use only products labeled for that use; the label is the law. If you hire someone to treat a lawn, make sure they hold your state’s pesticide applicator license; see our pesticide applicator license guide. To put a name to a lawn weed, use our weed identification guide.

Questions we get about St. Augustinegrass

Similar lawn grasses

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