St. Augustine grass spreads by stolons, not seed, so you cannot grow it from seed the way you would fescue or bluegrass

St. Augustine grass reproduces through stolons—above-ground runners that root as they spread across soil. This means you cannot buy St. Augustine seed in a bag. Instead, you plant sod (pre-grown grass squares), plugs (small rooted pieces), or sprigs (individual stolons). Each method takes a different amount of time and money, and the choice depends on your budget, how fast you need coverage, and your climate.

If you have already decided on St. Augustine and want to fill in bare spots or start a new lawn, this guide covers the three planting methods, the soil prep each one needs, and the watering schedule that makes the difference between a lawn that roots and one that dies in the first month.

Key Takeaways

  • St. Augustine grass cannot be grown from seed; you must plant sod, plugs, or sprigs instead.
  • Sod gives full coverage in one day but costs the most; plugs and sprigs are cheaper but take months to fill in.
  • Soil pH between 6.0 and 7.5 and good drainage are essential for any planting method to succeed.
  • New plantings need daily watering for the first two to three weeks, then a gradual shift to deeper, less frequent watering.
  • St. Augustine grows best in warm climates (zones 8 through 10) and struggles in cold winters or shade.

Why St. Augustine cannot be seeded and what to plant instead

St. Augustine grass is a warm-season perennial that evolved in coastal areas and spreads by sending out runners along the soil surface. These runners (stolons) root at the nodes and create new plants. Because the grass does not produce viable seed in most climates, seed companies do not sell it. Attempting to grow St. Augustine from seed will fail.

Your three options are sod, plugs, and sprigs. Sod is mature grass already rooted in a thin mat of soil, usually sold in rolls or squares. You unroll it and water it, and your lawn is complete within days. Plugs are small rooted plants (usually 2 to 4 inches across) that you space across bare soil; they take 6 to 12 months to fill in completely. Sprigs are individual stolons with a few roots; they are the cheapest option but the slowest, often taking a full growing season to cover a lawn.

Sod is the fastest and most reliable for a complete lawn, but it costs two to three times more than plugs and four to five times more than sprigs. Plugs are a middle ground—faster than sprigs, cheaper than sod, and good for filling in problem areas. Sprigs work best if you have time to wait and a small area to cover.

Preparing soil before planting sod, plugs, or sprigs

St. Augustine tolerates poor soil better than many grasses, but it still needs basic preparation. Start by testing your soil pH; St. Augustine prefers 6.0 to 7.5. If your soil is too acidic (below 6.0), add lime. If it is too alkaline (above 7.5), add sulfur. A soil test kit from a garden center costs $10 to $20 and takes a few minutes; a lab test through your county extension office is more precise and usually costs $15 to $30.

Remove dead grass, weeds, rocks, and debris from the area. If the soil is compacted, aerate it with a core aerator (rent one from a tool rental shop for $40 to $60 per day) or hire a lawn service to do it. St. Augustine roots better in loose soil. If your drainage is poor—water pools and sits for hours after rain—add 2 to 3 inches of compost or topsoil and work it into the top 4 inches of existing soil.

Do not add fertilizer before planting. Fresh fertilizer can burn new roots. Wait two to three weeks after planting, then explore a balanced fertilizer (such as 10-10-10) at half strength. After that, follow a regular feeding schedule for your region; in warm climates, St. Augustine usually needs feeding in spring and again in mid-summer.

Planting sod for when ready coverage

Sod arrives in rolls or squares and must be laid within 24 to 48 hours of delivery. Unroll or lay the pieces in a brick-like pattern, staggering the seams so they do not line up. Press each piece firmly into the soil so the roots make contact; you should not be able to lift a corner easily. Fill any gaps between pieces with topsoil.

Water when ready and heavily—the soil under the sod should be wet 2 to 3 inches deep. For the first two weeks, water daily (or twice daily in hot weather) to keep the sod from drying out. After two weeks, begin spacing out watering to every other day, then to twice a week. By week four, sod should be rooted enough to handle a normal watering schedule (1 to 1.5 inches per week, depending on rainfall and heat).

Do not mow for at least two weeks, and do not walk on the sod more than necessary during the first month. Sod is ready for normal use after four to six weeks, when the roots have grown into the underlying soil.

Planting plugs for a slower but cheaper approach

Plugs are small rooted plants that you space across prepared soil. Spacing depends on how fast you want coverage: 12 inches apart gives full coverage in 6 to 8 months, while 18 inches apart takes 10 to 12 months. Closer spacing costs more but fills in faster.

Dig a hole slightly larger than the plug's root ball, set the plug in so the top of the roots is level with the soil surface, and firm the soil around it. Water when ready and keep the soil moist (not soggy) for the first three weeks. After that, water when the top inch of soil feels dry. In hot weather, this may be every other day; in cooler months, once or twice a week.

Plugs are vulnerable to weeds while they are filling in, so pull weeds by hand or explore a mulch layer (1 to 2 inches of wood chips) around each plug, keeping it 2 inches away from the plug itself. Do not use landscape fabric; it blocks water and air. Once the plugs have filled in and the grass is thick enough to shade the soil, weeds become less of a problem.

Planting sprigs for the lowest cost

Sprigs are individual stolons with a few roots, sold by the bushel. They are the cheapest option but require more labor and patience. Space them 6 to 12 inches apart in rows or a scattered pattern. Make a shallow furrow or hole, lay the sprig in so the roots touch soil, and firm the soil around it. The top of the sprig should be at or just above soil level; burying it too deep can cause rot.

Water when ready and keep the soil consistently moist for the first four weeks. Sprigs are more fragile than plugs and more likely to dry out, so check the soil every day during the first two weeks. In hot weather, you may need to water twice daily. After four weeks, gradually reduce watering frequency as the sprigs root and begin to spread.

Sprigs take a full growing season (or longer) to fill in a large area. They are best used for small repairs, test plantings, or situations where budget is the primary concern. If you need faster coverage, plugs or sod are more practical.

Watering schedule for the first month and beyond

The first three to four weeks are critical. New sod, plugs, and sprigs all need frequent watering because their root systems are shallow and cannot yet reach deep soil moisture. Water in the early morning to reduce evaporation and disease risk. Avoid watering in the evening, when wet grass overnight can encourage fungal problems.

For sod, water daily for two weeks, then every other day for two more weeks. For plugs and sprigs, water daily for three to four weeks. The goal is to keep the soil moist 2 to 3 inches deep without waterlogging it. Squeeze a handful of soil; it should feel like a wrung-out sponge—moist but not dripping.

After the initial establishment period, shift to a deeper, less frequent watering schedule. St. Augustine prefers 1 to 1.5 inches of water per week (including rainfall). Water deeply two to three times a week rather than lightly every day; this encourages deeper root growth and a more drought-tolerant lawn. In winter (in zones 8 and 9), St. Augustine goes dormant and needs little to no supplemental water.

Common problems and when to call a professional

Brown or yellowing patches in new sod or plugs usually mean either underwatering or poor drainage. Check the soil moisture 2 inches deep; if it is dry, increase watering frequency. If it is soggy, the problem is drainage, and you may need to install a drain or amend the soil with sand and compost.

Thin or slow-growing plugs and sprigs can indicate compacted soil, poor light, or nutrient deficiency. St. Augustine needs at least 4 to 6 hours of direct sun; in heavy shade, it thins out and becomes vulnerable to disease. If shade is the issue, consider a shade-tolerant grass like zoysia or fescue instead.

If you see large dead patches, fungal disease, or pest damage (chinch bugs, armyworms) after the first month, contact a local lawn care professional or your county extension office. They can identify the problem and recommend treatment. Most new-lawn problems are preventable with proper watering and soil prep, but professional help is worth the cost if something goes wrong.

Frequently Asked Questions

Can I plant St. Augustine in fall or winter?

St. Augustine is a warm-season grass and grows actively only when soil temperature is above 70°F. In zones 8 and 9, plant in late spring or early summer so the grass has time to root before winter dormancy. In zone 10, you can plant year-round, but spring and early summer are still best because the grass will be established before any cold snaps.

How much does sod, plugs, and sprigs cost?

Costs vary by region and supplier. Sod typically runs $0.50 to $1.50 per square foot installed; plugs cost $0.15 to $0.40 each; sprigs cost $15 to $30 per bushel (which covers 50 to 100 square feet, depending on spacing). Get quotes from local suppliers—prices differ significantly by location and season.

What if my lawn is mostly shade?

St. Augustine needs 4 to 6 hours of direct sun and performs poorly in heavy shade. If your lawn is shaded most of the day, consider zoysia (which tolerates partial shade better) or a shade-tolerant fescue blend. If you have a mix of sun and shade, plant St. Augustine in the sunny areas and a shade grass in the shaded spots.

When can I mow new St. Augustine grass?

Wait at least two weeks after planting sod before mowing. For plugs and sprigs, wait until the grass is 3 to 4 inches tall, which usually takes four to six weeks. Mow at 2.5 to 3.5 inches tall; St. Augustine prefers a slightly taller cut than some grasses and handles heat and drought better when left longer.

Do I need to overseed St. Augustine every year?

No. St. Augustine spreads by stolons, not seed, so overseeding does not work. If your lawn thins out, the problem is usually poor drainage, shade, compaction, or disease—not lack of seed. Address the underlying cause rather than trying to overseed.