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Overseeding St Augustine With Bermuda

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Bermuda grass and St. Augustine grow in similar climates: hot, humid climates with a lot of rain. However, homeowners from South Florida to Central Texas can see that drought, disease, heavy traffic, or severe heat can cause a St. Augustine lawn to fail. To make your lawn more successful, combine the two types of grass.

Naturally, you’ll want to know how to properly care for the grass and keep it happy and growing, as each grass has its own strengths and limitations. In our guide, you can learn more about whether St Augustine Bermuda grass is a good mix and will work to cover bare spots. Bermuda grass is often used on golf courses, passing durability tests.

The question is, will it be the best grass to mix with St Augustine? By the end, you’ll have enough information on care tips and use cases to see what Bermuda grass requires and if you can use Bermuda Grass with St Augustine grass for a healthy lawn. (Read Grape Leaves Turning Brown – What To Do)

overseeding st. augustine

Will Bermuda Grass Take Over Saint Augustine Grass?

Bermuda grass is regarded as an invasive grass in many locations: and it may ultimately take over a St. Augustine lawn.

Bermuda spreads via two mechanisms: sprawling root systems (rhizomes) and invasive runners (stolons). St. Augustine grass only spreads from above-ground stolons.

A Bermuda grass with St. Augustine, mowed at 1.5 inches, will encourage Bermuda to expand and choke out St. Augustine in perfect conditions. Mow frequently to keep St. Augustine at a low level.

During the peak summer months, it’s also a good idea to restart Bermuda’s growth with monthly fertilizer.

It can take longer for Bermuda grass to take over St. Augustine. However, removing any existing St. Augustine grass before overseeding with Bermuda for the most outstanding results.

st. augustine grass

What Do You Overseed St Augustine With?

Determine the following to evaluate if overseeing St. Augustine grass with Bermuda is a credible choice.

  • Is your lawn covered with invasive Bermuda grass?
  • Is your lawn exposed to the sun during the midday hours?
  • Does Bermuda grass sow in a small area perform well?

If you answered yes to one or more of these questions, there’s a strong possibility mixing Bermuda grass with other grasses will do well in your lawn and may even naturally choke out weeds.

Because of the local soil characteristics, many St. Augustine lawns in the southeast perform poorly, but Bermuda grows much more easily naturally.

Mixing Bermuda grass could be the answer if your lawn fails despite your regular St. Augustine grass care with mowing, watering, and fertilizing. (Read Will Roundup Kill Fish In A Pond)

Do You have a Bermuda-Friendly Yard?

1. Invasive Bermuda:

If invasive Bermuda Grass has already taken root in your yard, you may be sure it’s Bermuda Lawn territory. Many homeowners view Bermuda as a problem, but you may opt to welcome it.

adequate sunlight

2. Adequate Sunlight:

Bermuda grass will not grow in shady locations since it does not tolerate shade. Bermuda grass is unsuitable if your lawn is shaded for a substantial amount of the day. If your lawn gets a lot of sun during the day, it’s excellent Bermuda territory.

3. Bermuda Grows where St. Augustine grass has failed:

Remove a 3-foot-square portion of St. Augustine grass or test a bare patch of yard. Plant Bermuda grass there and water it as a fresh lawn. If Bermuda grass sprouts and grows well in your yard, it’s probably a good choice. (Read Spray Roundup Before Rain Guide)

How to Overseed St. Augustine with Bermuda

You can begin overseeding if your lawn is already a Bermuda refuge, receives plenty of sunlight, and/or an overseeding test goes well. Keep in mind that putting out some Bermuda seeds and hoping for the best will not yield good results. Bermuda seeds will not sprout because of the existing St. Augustine.

Follow these methods to change a St. Augustine lawn into a pure Bermuda grass lawn:

1. Remove your St. Augustine

Using an Augustine sod cutter, remove the existing St. Augustine grass sod. The grass, thatch layer, and roots will all be removed, leaving a clean slate for Bermuda overseeding. Some people recommend killing St. Augustine grass using a glyphosate-based weed killer; however, this method requires chemicals and leaves you with the arduous task of removing all the dead grass afterward.

Bermuda grass will struggle to thrive on a spongy bed of dead St. Augustine. Using a sod cutter to remove all grass will save you time and money when overseeding Bermuda grass seeds. (Learn How To Kill Banana Trees)

2. Overseed with Bermuda

Cast your Bermuda grass seed according to the volume specifications on the container once the St. Augustine grass has been removed and the ground has been prepped for overseeding. Then, meticulously to avoid future weeds and promote healthy growth, water, and care for the new seed. Finally, overseed Bermuda grass in late spring to establish itself during the summer growing season and deliver the most remarkable results.

Mixing Bermuda Grass Without Killing St. Augustine First?

Bermuda grass may take root among St. Augustine. This, however, is dependent on the yard. Do the following for mixing Bermuda grass with existing St Augustine Grass to get the greatest results.

1. Scalp Your Lawn

Reduce the height of your St. Augustine to 0.5 inches. By cutting your lawn, you enhance the chances of Bermuda seedlings receiving enough sunshine. In addition, the current St. Augustine will also prevent your Bermuda seed from germinating if you don’t scalp your lawn.

2. Overseed with Bermuda

As you would on a barren lawn, spread Bermuda seed over the scalped St. Augustine. Overseed in the spring and water, fertilize and care for new Bermuda seed according to the manufacturer’s instructions. Because the seedlings must fight St. Augustine, they will need all the help they can receive.

mowing low

3. Mow Low

St. Augustine and Bermuda have different growth patterns, although they are both warm-season grasses. Bermuda is a low-growing grass that should be mowed at 1.5–2 inches, whereas St. Augustine works best when mowed at 3–3.5 inches. Continue to mow your newly seeded yard at 1.5 inches as your Bermuda grass grows in to ensure that it gets enough sunshine.

Is Bermuda Grass Crowded Out St Augustine?

You may be able to mix St. Augustine and Bermuda in your yard by scalping your St. Augustine and overseeding with Bermuda. Expect an uneven mix, just as you wouldn’t expect when overseeding warm-season grass with cool-season grass in the fall.

Bermuda will likely take over your yard’s sunny spots, where the heat can damage St. Augustine. Meanwhile, St. Augustine may thrive in shady areas of your lawn. The end effect might be a yard with Bermuda grass islands surrounded by vivid green St. Augustine.

Is It Possible To Mix Bermuda grass With St. Augustine Grass?

To make your lawn more successful, combine the two types of grass.

St. Augustine Grass is a type of sod used to create a lawn rather than using St Augustine grass seed. It spreads via above-ground stolons which then root into the soil, helping in the rapid spread of the plant. As a result, many people think of St. Augustine as aggressive because, if properly maintained, it can choke out weeds.

The most shade-tolerant grass is St. Augustine. However, the warm-season grass zone is where St. Augustine thrives. Southern New Mexico and Arizona and many Texas, Louisiana, Mississippi, Alabama, Georgia, South Carolina, and Florida are part of this zone.

Bermuda is a turf grass that spreads by rhizomes and stolons. Stolons fill in bare patches while rhizomes grow underneath the ground. In most climates, Bermuda is a more aggressive grass than St. Augustine. As a result, Bermuda is increasingly being used for outdoor sports fields.

Bermuda grass is more drought-resistant, doesn’t tolerate shade, and must be mowed very short. As a result, Bermuda’s growth potential is greater. In addition, Bermuda grass grows in the transition zone, which means it can grow in much more of the US than St. Augustine grass. (Read When Is It Too Cold To Water Plants)

Will Bermuda Grass take over St. Augustine Grass?

It can take over St Augustine if you don’t follow the proper steps. Here’s how to ensure you can keep Bermuda from overtaking St. August.

Bermuda Grass St. Augustine Grass
Mow to 1”–2” Mow to 2.5”–4”
Irrigation of 1” of water when grass shows drought stress Irrigation of 2” of water when lawn shows drought stress
Fertilizer: Use 1–2 lbs. of nitrogen per growing season for each 1,000 sq ft. Use 2–4 lbs. of nitrogen fertilizer per growing season for each 1,000 sq ft.
Suffers from Large patch, dollar spot, spring dead spot Suffers from Chinch bugs, brown patch, gray leaf spot

St. Augustine grows slower than Bermuda but can form a thick turf that can choke weeds in your lawn. Growing taller blades but mowing frequently helps keep the lawn thick.

Many ways to handle Bermuda grass with St. Augustine law. However, do not spray the grass with weed killers or pesticides as it can affect both types of grass.

St. Augustine performs well with frequent mowing twice weekly at a high level of 4”.

Sharpen your blades. A sharp blade ensures a cleaner cut. This clean-cut encourages healthy grass.

The tall grass will shade Bermuda and promote St. Augustine’s development while inhibiting Bermuda’s growth.

Let grass clippings fall back onto the grass and eventually into the soil. The clippings return nitrogen to the soil and shade the Bermuda grass.

Avoid using St. Augustine grass in high-foot traffic locations. Heavy foot traffic on a lawn encourages Bermuda to fill bare spots quickly.

Can You Seed Over St Augustine?

It’s tempting to overseed a failing St. Augustine lawn with Bermuda grass if it has brown areas or chinch bugs. But, before doing so, make sure your lawn has Bermuda grass and the light conditions are ideal. Using a sod cutter to remove all existing St. Augustine grass before overseeding with Bermuda grass is the best way to turn a struggling St. Augustine into a green lawn.

St. Augustine turf and Bermuda are warm-season grasses, although their growth patterns differ. St. Augustine works best when mowed at 3–3.5 inches, while Bermuda performs best at 1.5–2 inches. Therefore, continue mowing your lawn at 1.5 inches to allow adequate sunlight for your Bermuda grass.

Many people seed Bermuda grass for a thick lawn. This seeding prevents erosion and holds the newly sown section in place without creating mud puddles. Along with the seed, homeowners plant St. Augustine sprigs. They take longer to root and flourish, but they quickly spread and shade Bermuda once established. (Read When Is It Too Cold To Plant Grass Seed)

This method works in hot, humid grass zones. However, Bermuda will likely take control because St. Augustine cannot tolerate cooler temperatures. Remember that weed killer can injure your lawn if used regularly. It’s difficult to identify spray out-of-control grasses. The bare spots of soil left are prime real estate to attract weeds, complicating the quest to keep a lawn healthy.

Pulling grass is nearly as bad for your lawn. Detachment of roots and runners promotes new growth. Many types of grass can emerge from soil-left roots. When you pluck one plant, others may grow back.

You can control invading grasses by adjusting your lawn’s maintenance schedule.

This lawn care schedule includes:

  • Evaluate soil texture
  • Determine pH and nutrient levels
  • Create a turf-specific irrigation schedule
  • Keep the grass cut at the correct height
  • Sharpen your mower’s blade

All grass types have specific maintenance requirements. However, a thriving yard with ideal lawn care can fight off invading grasses with little intervention.

Overseeding St Augustine With Bermuda (1)