Mixing Bermuda Grass With St Augustine Grass

If you want a lawn that can handle almost anything, consider mixing bermuda grass with st augustine grass. This combination creates a turf that’s tough, attractive, and adaptable, giving you the best traits of both popular southern grasses.

Think of it as building a team. Each grass has a specialty. By putting them together, you cover each other’s weaknesses. The result is a lawn that stays greener longer, fights off weeds better, and recovers from damage faster than a single grass type might on its own.

This isn’t about creating a checkerboard. It’s about letting these grasses grow together in the same space. They fill in for each other, creating a dense, interwoven mat. This approach is especially smart in regions where weather can be unpredictable, or if your lawn has both sunny and shady spots.

Why This Grass Mix Works So Well

Each grass brings something unique to the table. Their natural growth habits complement one another, creating a more resilient whole.

Bermuda’s Strength: Bermuda grass is a champion of full sun and heat. It’s drought-tolerant once established and handles heavy foot traffic beautifully. It grows aggressively with runners (stolons) and underground stems (rhizomes), which helps it repair bare spots quickly.
St. Augustine’s Strengths: St. Augustine excels in shade tolerance, which is bermuda’s biggest weakness. It also forms a thick, coarse carpet that naturally chokes out many weeds. It prefers more moisture and creates a lush, green look.

When combined, they cover more environmental conditions. The bermuda thrives in the sunny, high-traffic areas, while the St. Augustine fills in the shadier, damper parts of your yard. Their different growth patterns also create a denser turf, leaving little room for weeds to take hold.

Potential Challenges to Consider

This mix isn’t perfect for every single situation. Being aware of the drawbacks helps you manage them.

Different Maintenance Needs: This is the biggest hurdle. Bermuda grass likes to be cut short (1-2 inches). St. Augustine needs a higher cut (2.5-4 inches) to stay healthy. You’ll need to find a middle ground, likely around 2.5-3 inches, which is okay for both but ideal for neither.
Aggressive Competition: In perfect conditions with full sun, bermuda grass can sometimes outcompete and overtake the St. Augustine because it grows so fast. You might need to overseed or plug the St. Augustine occasionally in sunny areas.
Watering Balance: St. Augustine likes more consistent moisture than bermuda. You’ll water for the St. Augustine’s needs, which the bermuda will tolerate just fine.

Step-by-Step Guide to Establishing Your Mixed Lawn

You can start a mixed lawn from scratch or introduce one grass into an existing lawn. Here’s how to do it effectively.

Starting a New Lawn From Scratch

Test and Prepare Your Soil: Get a soil test first. Amend the soil based on the results, aiming for good drainage and a slightly acidic pH. Till the area thoroughly and rake it smooth, removing any rocks or old roots.
Choose Your Planting Method: For a mix, using sod is often the most reliable and fastest method. You can lay strips of bermuda sod alternated with strips of St. Augustine sod. Alternatively, you can use a mix of plugs for both grasses, planting them in a staggered pattern across the lawn.
Plant and Water Deeply: Install your sod or plugs according to best practices. Water immidiately and deeply to establish the roots. Keep the top inch of soil consistently moist for the first 2-3 weeks.
Follow Initial Care: Avoid heavy traffic for the first month. Hold off on fertilizer until you see steady new growth, usually around 4-6 weeks after planting.

Introducing One Grass to an Existing Lawn

If you already have a bermuda lawn but need shade tolerance, adding St. Augustine is a common tactic.

Mow Low and Dethatch: Mow your existing bermuda grass quite short. Dethatch it to remove the layer of organic debris so the new grass has soil contact.
Plant St. Augustine Plugs: In the shady areas where bermuda struggles, plant St. Augustine plugs. Space them about 12-18 inches apart. You can also use small pieces of sod.
Water and Monitor: Water the new plugs diligently. The existing bermuda will also grow to fill in gaps, creating a natural blend where the two grasses meet.

Long-Term Care for Your Resilient Lawn

Ongoing maintenance is about compromise and observation. Your goal is to keep both grasses reasonably happy.

Mowing: Set your mower to a height of 2.5 to 3 inches. This is a bit high for bermuda but necessary for the St. Augustine. Never remove more than one-third of the grass blade in a single mowing.
Watering: Water deeply but less frequently, aiming for about 1 inch of water per week, including rainfall. Water in the early morning so the blades dry quickly, preventing fungal disease which St. Augustine can be prone to.
Fertilizing: Use a balanced, slow-release fertilizer. Both grasses benefit from regular feeding during their active growing season (late spring through summer). Follow soil test recommendations to avoid over-fertilizing, which can lead to thatch.
Aeration and Dethatching: Aerate your lawn annually, especially if you have heavy soil. This helps water and nutrients reach the roots of both grasses. Dethatch if the layer becomes thicker than half an inch.

FAQ: Mixing Bermuda and St. Augustine Grass

Will one grass eventually kill the other?
Not necessarily. In balanced conditions of sun and shade, they often coexist. In full sun, bermuda may dominate. In deep shade, St. Augustine will take over. This is actually the point—each grass grows where it’s strongest.

What’s the best mowing height for a mixed bermuda and St. Augustine lawn?
A height of 2.5 to 3 inches is the best compromise. It protects the St. Augustine’s crowns while still allowing the bermuda to spread laterally.

Can I just overseed bermuda into my St. Augustine lawn?
You can, but it’s tricky. St. Augustine is too dense for bermuda seed to easily reach soil. Using plugs or sprigs of bermuda is a more reliable method for introduction.

Is this mix good for high-traffic areas?
Yes, particularly because of the bermuda component. The bermuda’s traffic tolerance combined with the dense mat of St. Augustine creates a lawn that can handle more play and activity than a pure St. Augustine lawn.

What about weed control?
The dense turf itself is excellent weed prevention. For herbicide use, you must be extreemly careful. Many weed killers safe for bermuda can severely damage or kill St. Augustine. Always read labels carefully and spot-treat weeds when possible.

Mixing bermuda grass with st augustine grass is a practical strategy for a resilient, year-round lawn. It asks for a little more attention to detail in maintenance, but the payoff is a beautiful, durable green space that leverages the strengths of two of the South’s most reliable grasses. By understanding their needs and managing the compromise, you can create a turf that’s truly greater than the sum of its parts.