St. Augustine grass sodding or plugging should happen during warm months when soil temperatures consistently stay above 65°F. Knowing exactly when to plant St Augustine grass can mean the difference between a thick, green lawn and a patchy, struggling one. This grass type loves heat and hates frost, so timing is everything if you want it to thrive.
In this guide, we’ll walk you through the best planting windows, how to check soil temps, and what to do if you miss the ideal season. You’ll get step-by-step instructions that are easy to follow, even if you’re new to lawn care.
When To Plant St Augustine Grass
The short answer is: plant St. Augustine grass in late spring through early summer. This gives the grass plenty of time to establish strong roots before cooler weather arrives. Soil temperature is the most important factor, not just the calendar date.
If you plant too early, cold soil can kill the sod or plugs. If you plant too late, the grass won’t have enough time to root before winter dormancy. Let’s break down the specifics for different regions.
Best Planting Windows By Region
St. Augustine grass grows best in warm, humid climates. It’s common in the southern United States, from Florida to Texas and up the Gulf Coast. Here are the typical planting windows:
- Gulf Coast and Florida: March through July. You can sometimes plant into August, but earlier is better.
- Texas and Oklahoma: April through June. Avoid planting during the hottest part of summer if possible.
- California and Southwest: April through June. Coastal areas may have a slightly longer window.
- Transition Zone (like Tennessee or North Carolina): May through June. These areas have colder winters, so planting early is critical.
These are general guidelines. The real test is soil temperature, which we’ll cover next.
Why Soil Temperature Matters Most
St. Augustine grass roots stop growing when soil temps drop below 65°F. They also struggle if the soil is too hot, above 95°F. The sweet spot is 70°F to 85°F. You need consistent warmth, not just a few warm days.
To check your soil temperature, use a simple soil thermometer. Insert it 4 inches deep in the ground. Take readings in the morning and afternoon for a few days. When the average stays above 65°F, you’re good to go.
You can also look for signs like grass starting to green up naturally in your area. That’s a good indicator that soil is warming up.
How To Plant St Augustine Grass Step By Step
Once you’ve determined the right time, follow these steps for the best results. Preparation is just as important as the planting itself.
Step 1: Test And Amend Your Soil
St. Augustine grass prefers a soil pH between 6.0 and 7.5. Get a soil test kit from your local extension office or garden center. If your pH is off, add lime to raise it or sulfur to lower it. Do this at least two weeks before planting.
Also, make sure the soil is loose and well-draining. Compacted soil will stunt root growth. Till the area to a depth of 4 to 6 inches, and remove any rocks, weeds, or debris.
Step 2: Choose Your Planting Method
You have three main options: sod, plugs, or seed. St. Augustine grass is rarely grown from seed because it’s not reliable. Most people use sod or plugs.
- Sod: Best for instant results. It’s more expensive but gives you a full lawn immediately. Plant sod within 24 hours of delivery.
- Plugs: Cheaper but slower. You plant small sections of grass in a grid pattern. It takes several months to fill in completely.
For small areas or repairs, plugs work fine. For a whole lawn, sod is usually the better choice.
Step 3: Plant At The Right Depth
For sod, lay the strips tightly together, but don’t overlap them. Stagger the seams like bricks. Press the sod firmly into the soil so the roots make contact. Water immediately after laying.
For plugs, dig holes about 6 to 12 inches apart. Place each plug so the top is level with the soil surface. Don’t bury the leaves. Water well after planting.
Step 4: Water Correctly
New St. Augustine grass needs consistent moisture. For the first two weeks, water daily to keep the soil damp but not soggy. After that, gradually reduce watering to every other day. By week four, you can water deeply once or twice a week.
Overwatering can cause root rot and fungus. Underwatering will dry out the sod or plugs. Check the soil moisture by sticking your finger into the ground near the roots.
Common Mistakes When Planting St Augustine Grass
Even with good timing, people make errors that ruin their lawn. Here are the most common ones to avoid.
Planting In Shade
St. Augustine grass needs at least 4 to 6 hours of direct sunlight daily. It can tolerate some shade, but too much will cause thin, weak growth. If your yard is heavily shaded, consider a different grass type or trim trees to let in more light.
Ignoring Soil Preparation
Throwing sod on top of hard, rocky soil is a recipe for failure. The roots need loose soil to spread. Always till and amend the soil before planting. This is one step you can’t skip.
Planting Too Deep
Burying the grass too deep smothers the roots and prevents air circulation. The top of the sod or plug should be level with the soil surface. If you see soil covering the leaves, you’ve planted too deep.
Not Watering Enough
New St. Augustine grass is thirsty. If you skip a watering day during the first week, the roots can dry out and die. Set a schedule and stick to it, especially if the weather is hot and windy.
When To Plant St Augustine Grass In Different Seasons
Let’s look at what happens if you plant outside the ideal window. Each season has its own risks and benefits.
Spring Planting (March To May)
Spring is the best time for most regions. The soil is warming up, and there’s plenty of rain in many areas. You’ll have fewer weed problems because the grass can establish before summer weeds appear. Just watch out for late frosts. Wait until the last frost date has passed in your area.
Summer Planting (June To August)
Summer planting works, but it’s riskier. The heat can stress new grass, and you’ll need to water more often. If you plant in July or August, make sure you can commit to daily watering. Also, avoid planting during a heatwave. Wait for a cooler spell if possible.
Fall Planting (September To November)
Fall is not recommended for St. Augustine grass. The grass needs 8 to 12 weeks to establish before the first frost. In most regions, that window closes by September. If you plant in fall, the grass may not survive winter. Only attempt this in very warm climates like South Florida or Hawaii.
Winter Planting (December To February)
Never plant St. Augustine grass in winter. The soil is too cold, and the grass will go dormant or die. Wait until spring. If you have bare spots, just cover them with mulch until the weather warms up.
How To Care For Newly Planted St Augustine Grass
After planting, your job isn’t done. Proper care during the first few months sets the foundation for a healthy lawn.
Mowing Tips
Wait until the grass reaches 4 inches tall before mowing. Then set your mower blade to 3.5 to 4 inches. St. Augustine grass should be kept tall. Cutting it too short stresses the plant and encourages weeds. Never remove more than one-third of the leaf blade at a time.
Fertilizing Schedule
Don’t fertilize immediately after planting. Wait about 4 to 6 weeks. Then use a slow-release nitrogen fertilizer. Apply again every 6 to 8 weeks during the growing season. Stop fertilizing 6 weeks before the first expected frost to avoid tender growth that could be damaged by cold.
Weed Control
New grass is vulnerable to weeds. Hand-pull any weeds you see during the first month. After the grass is established (about 8 weeks), you can use a pre-emergent herbicide labeled for St. Augustine. Avoid broadleaf weed killers until the grass is fully rooted.
Frequently Asked Questions About Planting St Augustine Grass
Can I Plant St Augustine Grass In The Shade?
St. Augustine grass can tolerate some shade, but it needs at least 4 to 6 hours of direct sunlight. If your yard is heavily shaded, consider a shade-tolerant variety like ‘Seville’ or ‘Palmetto’. Even then, expect thinner growth than in full sun.
How Long Does It Take For St Augustine Grass Plugs To Fill In?
Plugs typically take 3 to 6 months to fill in completely, depending on spacing, soil conditions, and weather. Plant plugs 6 to 12 inches apart for faster coverage. Keep the soil moist and fertilize after 4 weeks to speed up growth.
What Is The Best Month To Plant St Augustine Grass In Texas?
In Texas, the best months are April through June. This gives the grass time to root before the intense summer heat. In southern Texas, you can plant as early as March. In northern Texas, wait until May to avoid late frosts.
Can I Plant St Augustine Grass Over Existing Grass?
It’s not recommended. Existing grass and weeds will compete with the new St. Augustine. You should kill the old grass first using a non-selective herbicide or by solarization. Then till the soil and plant fresh sod or plugs.
Do I Need To Water St Augustine Grass Every Day After Planting?
Yes, for the first two weeks, water daily to keep the soil moist. After that, reduce to every other day for two more weeks. By week four, you can switch to deep watering once or twice a week. Adjust based on rainfall and temperature.
Final Thoughts On Planting St Augustine Grass
Timing is the most important factor when you decide when to plant St Augustine grass. Stick to late spring or early summer, and always check your soil temperature first. Prepare the soil well, water consistently, and avoid common mistakes like planting too deep or in too much shade.
With the right approach, your St. Augustine lawn will be thick, green, and the envy of the neighborhood. Take it step by step, and don’t rush the process. Good luck with your planting!