How to Grow and Care for St. Augustine Grass

St. Augustine grass (Stenotaphrum secundatum) is a warm-season grass native to North America. It is a spreading, warm-season grass for lawns, especially in warm to hot, tropical climates. As a member of the Poaceae family, it is a true grass.

The grass has bluish-green leaves with 1/3-inch wide, flat blades. It has a low, creeping habit and spreads via stolons. forming dense mats that outcompete weeds. St. Augustine grass performs better in the shade than other warm-season turfgrasses. Another benefit is its salt tolerance, which makes it an ideal choice for coastal locations.

St. Augustine grass is sometimes also called buffalo grass, which can be confusing because it is different from the highly drought-tolerant buffalo grass Bouteloua dactyloides. It forms dense clumps, not a uniform lawn.

St. Augustine Grass vs. Bermuda Grass

St. Augustine grass and Bermuda grass both perform best in the warm climates of the southern United States. The grass blades are distinctively different: St. Augustine grass blades are coarser and broader than the less than 1/10 inch wide, soft, and delicately textured blades of Bermuda grass.

• Shade tolerance: St. Augustine grass also grows in shady spots, while Bermuda grass can't.
• Cold tolerance: Bermuda grass is slightly more cold-tolerant than St. Augustine grass.
• Drought resistance: Bermuda grass handles drought; it needs only half as much water as St. Augustine grass, which is considered a water hog.
• Fertilizer needs: St. Augustine grass needs almost twice as much fertilizer (heavier in nitrogen) as Bermuda grass. Bermuda grass requires about 1 to 4 pounds per 1,000 square feet per year, vs. St. Augustine grass, which needs 3 to 6 pounds per 1,000 square feet annually.
• Propagation: Bermuda grass can be grown from seed, while St. Augustine grass only grows from transplanted sod or plugs.
• Weed resistance: Sodded St. Augustine instantly chokes out any weeds. Its stolons or runners speedily overtake a Bermuda grass lawn grown from seed.
• Salt resistance: St. Augustine is a better choice for coastal areas because it tolerates salty conditions better than Bermuda grass.
• Cost difference: Sodding St. Augustine grass is significantly more expensive than seeding, so Bermuda grass is more cost-friendly. Also, Bermuda grass needs less fertilizer and watering.

St. Augustine Grass Care

For a lush St. Augustine lawn, you will have to keep up with mowing, irrigation, and fertilization.

As a warm-season turfgrass, plant St. Augustine grass in spring and summer in full sun with at least 90 days to establish before the first frost.

Light

St. Augustine grass prefers full sun but also tolerates some shade. But, for best results, grow St. Augustine grass in full sun. Of the warm-season grasses, St. Augustine grass is the most shade-tolerant.

Soil

The grass grows in a range of soil types, provided the soil has adequate fertility and good drainage. Waterlogged or compacted soil is not suitable. The soil pH should be between 5.0 and 7.5. In highly alkaline soil above 7.5, the grass starts to look chlorotic. Test the soil pH and amend the soil to lower the pH if necessary.

Water

St. Augustine grass requires consistent moisture. It performs best when you avoid either moisture extreme: too little or too much. Established St. Augustine grass needs deep yet infrequent watering. A telltale sign that the grass needs watering is when it appears to have a bluish hue. If you walk on the grass in the evening and the grass blades do not bounce back up, water the grass early the next morning. Watering to a lesser extent is also required during the dormancy period (when the grass is brown) to prevent desiccation in the winter.

Temperature and Humidity

St. Augustine grass handles heat and humidity well, which is why it is popular in regions such as the American Southeast.

Fertilizer

St. Augustine grass performs best if fertilized regularly and on a schedule. It is recommended to fertilize the grass three times between May and August at equal intervals. In early May, after the lawn has fully greened up, apply ½ to 1 pound of actual nitrogen per 1,000 square feet. Repeat in June or July, but this time use a high-potassium fertilizer such as 15-0-15. Repeat with the same high-potassium fertilizer before August 15. If the grass appears yellow, it might be lacking phosphorus, but you should only apply a fertilizer with phosphorous if a soil test reveals a deficiency.

Types of St. Augustine Grass

There are several different types of St. Augustine grass. Varieties include:

• Floratine: Offers narrower blades for a finer texture.
• Floratam: This variety is resistant to chinch bugs but not as cold-tolerant.
• Seville: Offers both a finer texture and resistance to chinch bugs, but it also lacks cold tolerance.

Disadvantages of St. Augustine Grass

• Not as hardy in cold weather as other grasses
• Not drought-tolerant
• Does not stay green in winter
• Needs a heavier fertilizer regimen
• Does not spread by seed; requires sodding or plugs
• Handles some foot traffic but not heavy, repeated traffic
• Susceptible to various pests

Planting St. Augustine Grass

St. Augustine grass is most commonly grown from sod (plugs), and it is in this form that turf farms or their retailers sell it to homeowners and landscapers. Since St. Augustine grass spreads so vigorously via its creeping stolons, it is easy to establish it from sod.

In USDA Zones 7 to 12, you can start a lawn of St. Augustine grass any time during the growing season. Space the pieces of sod 1 to 2 feet apart and water consistently to encourage its fast spread. If cared for properly, it grows fast enough to fill the gaps during the first year.

How to Grow St. Augustine Grass From Seed

Most St. Augustine seed is naturally sterile. St. Augustine grasses do not produce enough viable seeds for commercialization. It is rare to grow St. Augustine grass from seed. But, if you are lucky enough to find the seed and want to try your hand at it, sow it in late spring to early summer. Sow 1/3 to 1/2 of a pound of the seed per 1,000 square feet. Pay special attention to keeping the ground evenly moist until you see that the grass has not only sprouted but also begun to spread.

Overwintering

St. Augustine grass will only stay green all year if the soil temperature remains 60°F or warmer. Unless you live in the subtropical regions of Florida and California, St. Augustine grass will turn brown in winter. As long as you are in at least zone 7, don't worry: It's not dead, just dormant. It will become green again when warm weather returns.

Is This the Right Grass for You?

ST. AUGUSTINE GRASS IS GOOD FOR YOU IF:

• You live in a hot, humid climate.
• You live in a coastal area and need grass that tolerates salt.
• You need to fill bare spots in a partially shaded area.
• You don't mind starting your lawn with sod or plugs.
  

Common Pests and Diseases

Like all turfgrasses, St. Augustine grass is susceptible to pest and disease damage. The most common insect pests and diseases include:

• Chinch bugs: While these bugs feed on the grass, they inject a toxin into it that renders it unable to take up water properly so it dies. Prevention is the best way to control chinch bugs. Water as needed, especially during hot, dry spells, and dethatch your lawn whenever you detect substantial thatch build-up.
• Spittlebugs: From spring through fall, the adults and nymphs of spittlebugs suck the juices from the grass blades, similar to chinch bugs. Unlike chinch bugs, which feed in sunny areas, spittlebugs do their damage mostly in the shade. Keeping the lawn well-maintained and healthy is your first line of defense.
• Mole crickets: This pest feeds both on leaf blades and stems and on roots and tubers of St. Augustine grass. Detection is tricky and requires a soap flush of the area where you suspect them. If you find more than 2 to 4 crickets per square foot, control is warranted to prevent an infestation. Use a special insecticide or mole cricket bait for residential lawns.
• Grubs: The feeding of lawn grubs occurs on the roots and causes grass to gradually thin, yellow, and die or become soft and spongy. Lift the top 3 inches of soil to see if there is a substantial number of grubs present. Periodic scouting of grubs is the best defense, especially in late June, when they lay their eggs.
• Gray leaf spot: This fungus develops rapidly in warm and moist conditions, leading to considerable thinning of the turfgrass, especially in shaded areas. To prevent the fungus, do not apply soluble nitrogen fertilizers on moderately shaded lawns in the summer, and avoid watering late in the day when the grass surface remains wet for long periods.If the removal of grass in infected areas does not help, apply a fungicide.
• Large patch: Also known as rhizoctonia blight, this fungal disease infects St. Augustine grass between fall and spring when temperatures are below 80°F. It starts with round, discolored patches that get larger over time.As the disease reappears every year in conducive wet conditions, proper lawn care is your best bet to avoid it.
• Take-all root rot: Weak, brown, dead patches in St. Augustine grass are often caused by a fungal disease in the soil. It lives in thatch, so proper dethatching is key to prevent it. If your soil pH is in the neutral range, reducing it to slightly acidic levels helps to control the spread of the fungus.
• Downy mildew: In wet, humid conditions and poor air circulation, the grass develops downy mildew. It manifests itself through a range of symptoms: white streaks that run parallel to leaf veins, yellow leaves, brown leaf tips, and stunted growth. To prevent it, practice good garden hygiene. Water early in the day so that the grass blades have time to dry before nightfall. Dig out and dispose of any diseased patches of sod as soon as you find them.

• Is St. Augustine grass better for shade or sun?

  It thrives in full sun but also tolerates shaded areas that receive at least four hours of direct sunlight per day.

• Is St. Augustine grass a high-maintenance lawn grass?

  St. Augustine grass needs regular mowing, watering, dethatching, fertilizing, and monitoring for pests and diseases, which puts it in the category of high-maintenance lawn grass.
  

• How fast does St. Augustine grass spread?

  St. Augustine grass spreads at an average rate of6 to 12 inches per year, and in ideal conditions even faster.

• What happens if I don’t mow St. Augustine grass?

  If the grass is not mowed, it will flop over and deteriorate quickly. The recommended mowing height of St. Augustine grass is between 2 and 2 ½ inches.

From: thespruce