St. Augustine Grass Care Guide for Central Texas

Mow High: The Single Most Important Habit

St. Augustine is a tall-growing grass, and cutting it short is the fastest way to weaken it. Keep the mower set to 3 to 4 inches, and never remove more than one-third of the blade height in a single pass. Taller blades shade the soil, keep roots cooler through July and August, and crowd out weeds before they can germinate. A lawn scalped to 2 inches loses that shade, dries out faster, and opens the door to crabgrass and nutsedge.

Mow with a sharp blade so the grass is cut cleanly rather than torn. Torn blade tips turn ragged and brown and give fungus an easy entry point. During peak growth in late spring and early summer, that usually means mowing weekly; in the heat of midsummer and in dormancy, growth slows and you can stretch the interval. Leave the clippings on the lawn most of the time, since they break down quickly and return nitrogen to the soil.

Watering St. Augustine the Right Way

St. Augustine needs more water than other Central Texas turfgrasses, but the goal is still deep and infrequent, not shallow and daily. A soaking of roughly an inch per week, delivered in one or two sessions, trains roots to grow down instead of clustering at the surface. Frequent light sprinkling does the opposite: it keeps the top inch wet, encourages shallow roots, and creates the humid canopy that fungal disease loves.

Round Rock and most Central Texas cities restrict landscape irrigation to before 10 a.m. or after 7 p.m. on assigned days, and those hours happen to be ideal. Watering early lets blades dry before nightfall, which is the best defense against brown patch. Watering in the evening after 7 works too, but avoid soaking the lawn at dusk during humid weather. During official drought stages, watering days are cut further, so a properly zoned, well-adjusted sprinkler system that delivers even coverage matters even more.

• Target about 1 inch of water per week from rain plus irrigation combined.
• Water deeply in one or two sessions rather than a little every day.
• Run zones before 10 a.m. so blades dry quickly and fungus gets no foothold.
• Watch for footprints that stay pressed in and a blue-gray cast, the first signs the lawn needs water.
• Adjust or shut off the controller after rain; Central Texas averages around 35.5 inches a year, much of it in spring and fall bursts.

Working With Shade, Not Against It

The reason homeowners choose St. Augustine is its shade tolerance, the best of any warm-season grass grown here. It holds a healthy stand in filtered or partial shade where Bermuda would surrender. That said, no turfgrass thrives in deep shade. St. Augustine needs at least four to five hours of sun, or bright dappled light through the day, to stay dense.

If a patch keeps thinning under a heavy tree canopy, the fix is usually more light rather than more water or fertilizer, which only feed disease in low light. Thinning the tree canopy to let more sun through often revives the grass beneath. Where light is simply too low, a shade-tolerant groundcover or a mulched bed is a more honest long-term solution than fighting to keep grass alive in the dark.

Brown Patch and Take-All: The Two Diseases to Know

Fungus, not heat, is the leading killer of Central Texas St. Augustine. Brown patch (large patch) shows up in the cooler, humid weeks of spring and fall as roughly circular yellow-to-brown rings, often a few feet across, where the leaf pulls away easily from the runner. Take-all root rot is sneakier: irregular yellowing patches that thin out over a season as the roots rot, most common in stressed, over-watered, or high-pH lawns.

The best control for both is cultural, not chemical. Water in the morning so blades dry fast, avoid excess nitrogen in fall, mow at the right height with a sharp blade, and improve drainage in low spots where water lingers. For take-all, a light topdressing of peat moss can lower surface pH and slow the fungus. When disease is widespread, a targeted fungicide applied at the right timing helps, but it never substitutes for fixing the watering and mowing habits that invited the fungus in.

Fertilizing and Seasonal Timing

St. Augustine is a moderate feeder. Wait until the grass has fully greened up in spring, usually April in Central Texas, before the first feeding; fertilizing while the lawn is still waking from dormancy wastes product and can feed weeds. A slow-release nitrogen fertilizer applied in late spring and again in early fall covers most lawns. Avoid heavy nitrogen in the heat of midsummer and, importantly, in early fall right before brown patch season, since lush new growth is exactly what the fungus attacks.

A soil test every couple of years takes the guesswork out and prevents the over-fertilizing that stresses the lawn and pollutes runoff. Iron applications can green up the blades during summer without pushing the excessive growth that nitrogen causes. Match feeding to the calendar and the grass tells you it is working with steady color and density rather than a flush of soft, disease-prone growth.

Keep Your St. Augustine Lawn Thriving With Oakwood

A great St. Augustine lawn in Central Texas is mostly about system, not luck: mow tall, water deep and early, respect the shade, and stop fungus before it spreads. When a lawn needs more than routine care, though, the fixes usually involve grading, drainage, or an irrigation system that actually delivers even, efficient water within the city's watering windows.

Oakwood Landscaping is a TCEQ Licensed Irrigator, BBB accredited, licensed and insured. We install heat-hardy sod, design and repair sprinkler systems, and add smart controllers that automatically respect Round Rock's watering rules. Call (323) 606-0255 for a lawn and irrigation assessment across Round Rock, Austin, and Brushy Creek.