Bermuda grass will grow successfully when you spread Bermuda seed on a Centipede grass lawn. However, the two grasses don’t coexist well because they have different fertilizer needs. When overseeding a Centipede grass lawn with Bermuda, be prepared for the Bermuda grass to take over the Centipede grass. This is because Bermuda grass is much more aggressive and spreads much more quickly than Centipede grass. It’s best to plan for this and use overseeding as an opportunity to replace Centipede grass with a Bermuda lawn.
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Can You Mix Bermuda Grass with Centipede Grass?
Both Centipede grass and Bermuda grass are warm season grasses that flourish in similar climates. This means a yard that supports Centipede grass is also likely good for Bermuda grass. This may seem like a match made in heaven and cause you to believe you can mix the two grass species. However, the reality is different. Here’s why:
- Bermuda grass grows more aggressively than Centipede grass, causing it to choke out Centipede grass, particularly in sunny areas of the lawn.
- Centipede grass and Bermuda grass have very different fertilizer needs—what’s good for one is bad for the other.
- Your lawn is likely to take on a patchy appearance if you mix the two species. You will have dark green Bermuda grass in sunny areas and yellow-green Centipede grass in shadier portions.
Fertilizer needs are a big reason Centipede grass and Bermuda don’t mix well. Bermuda is a nitrogen-hungry grass that will struggle if it is not cared for with a frequent fertilizer schedule. Centipede grass, on the other hand, is actually harmed by frequent fertilizer applications. If you have a mix of Bermuda and Centipede grass, fertilizing for one species will harm the other. For this reason, you should not plan to cultivate both species in the same lawn.
How Do You Replace Centipede Grass with Bermuda?
Because mixing Centipede and Bermuda grass won’t work well, the best method to use when overseeding a Centipede lawn with Bermuda is to plan to fully transition to a Bermuda grass lawn. The following method allows you to replace Centipede grass with Bermuda without cutting sod or stripping your lawn to bare soil. Even better, the steps below allow you to see if your Bermuda seed performs well before making the decision to kill off your Centipede grass.
Before overseeding your Centipede grass, scalp the lawn to 1–1.5 inches in height (2.5–4 cm). This will remove most of the existing grass blade material, exposing more of the soil to air and sunlight. This ensures that when you spread your Bermuda grass seed, the seeds don’t get caught in the Centipede blades. The more seeds that reach the soil, the more sprouts you’ll get. Plus, with your Centipede grass cut low, more sunlight will reach your Bermuda seedlings, helping them survive.
Rent a power rake or dethatcher from your local hardware store and use it to dethatch your Centipede grass. Thatch is a naturally occurring buildup of grass stems between the green growing grass and the topsoil. This thatch will create a barrier that stops seeds from reaching the soil. Dethatch thoroughly to ensure your Bermuda seeds have a fighting chance.
Use a core aerator to thoroughly aerate your lawn. You can rent a core aerator from most hardware stores. The aeration process will loosen the soil, making it easier for your Bermuda seeds to take root. Mowing, dethatching, and aerating are a powerful trifecta that boosts the germination rate of any seed you spread.
Spread a 1/8–1/4 inch (3–6 mm) thick layer of compost over the areas of your lawn that will be overseeded with Bermuda grass. Use a garden rake to distribute the compost evenly, filling aeration holes and providing a thin cover that doesn’t smother the existing grass. In the next steps, this compost will be used to protect your Bermuda seed, keep it moist, and act as a lawn fertilizer.
Spread Bermuda Seeds
Now, it’s time to use a broadcast spreader to spread your Bermuda grass seed. Follow the instructions on the bag of Bermuda seed for the correct amount of seed to use per square foot. Then, spread the seed using an east-west pattern across the lawn before spreading seed in a north-south pattern. This will ensure even coverage.
Protect Your Seeds
Use your garden rake to cover the seeds with the compost you spread in step 4. By spreading the compost first, you will fill any aeration holes with compost, which prevents seeds from being buried too deeply to sprout. A thin layer of compost above and below the seeds provides a moist environment that encourages seed sprouting. Compost also protects the seeds from birds that would otherwise eat the grass seed.
Water Your New Seeds
Once the seeds are spread and covered, water the lawn for 10–15 minutes. From there on, it’s important to keep the soil moist so that the seeds will sprout and survive. For the first week, water twice per day for 10–15 minutes. In the second week, water once daily for 10–20 minutes. In the third week, water once every other day for 15–30 minutes. The right amount of water will give your new grass the right head start.
Apply a Starter Fertilizer
It’s imperative to give new grass seeds a boost to help them form blades and roots. Use this lawn starter fertilizer which was formulated specifically for new grass seed and sod. You can spread this fertilizer at the same time you spread your grass seed, or at any point in the first few weeks after seeding. It will greatly increase the number of grass seedlings that survive in your yard.
- Great starter fertilizer for new seed or sod.
- You can also use Pennington UltraGreen for overseeding or on an existing lawn.
- 5% Iron promotes a deep, thick, lush lawn.
Kill Your Centipede Grass Without Harming Your Bermuda
This final step is key when transitioning from a Centipede lawn to Bermuda grass. Follow the previous steps and wait 1–2 months to see the results of seeding. If the Bermuda grass seed is performing well, it’s time to kill off your Centipede grass and turn your lawn into a Bermuda haven. Here’s how:
- Spray your lawn with this herbicide that contains Quinclorac.
- The Quinclorac in the herbicide will kill weeds and Centipede grass, but it won’t harm Bermuda grass.
- If necessary, repeat the herbicide spray once every 30 days until the Centipede grass is dead and only the Bermuda is left.
If your Bermuda overseeding effort failed and you see very little Bermuda grass among your Centipede grass, don’t spray with weed killer. You can then decide to either attempt to reseed next year or stick with your Centipede lawn. This method works well because you can see the results of your overseeding, then kill off your Centipede grass once you’re ready to full transition to a Bermuda lawn. This prevents you from having a mixture of two grasses that can make your lawn appear patchy and uneven.
What is the Best Time to Overseed Centipede Grass with Bermuda Seed?
Bermuda grass experiences its strongest growth period in summer. To take advantage of this, spread any new Bermuda seed in late spring through early summer. Plan to overseed your Centipede lawn with Bermuda grass between May 1 and June 15. This will ensure the highest germination and survival rate of your grass seed.
Will Bermuda Grass Overtake Centipede Grass?
Bermuda grass will spread quickly and begin to choke out Centipede grass once the seed takes root. This is because Bermuda grass spreads both through aboveground stolons (runners) and belowground rhizomes (roots). Centipede grass spreads slowly in comparison. So, in a lawn where both grass types are present, Bermuda will start to overtake the Centipede grass.
- Bermuda grass is extremely likely to choke out Centipede grass.
- Bermuda grows more quickly and aggressively than Centipede grass.
- In many Centipede grass lawns, invasive Bermuda can be considered a problem.
A lot of homeowners with Centipede grass face yearly battles with invasive Bermuda. By overseeding with Bermuda grass on purpose, you can embrace this invasion and begin to transition from Centipede grass to Bermuda.
Is Bermuda or Centipede Grass Better?
Depending on the conditions in your yard, Bermuda or Centipede grass may be better. One good way to find out what is the best grass for your lawn is to use this at-home soil tester to measure the soil pH. A pH from 5–6 is best for Centipede grass, while a pH from 6–7 is better suited for Bermuda grass.
- Centipede grass tolerates acidic soil better than Bermuda grass.
- Bermuda grass very aggressively, filling bare patches better than Centipede grass.
- Centipede grass has the slowest growth of any warm-season grass, inhibiting its ability to repair damaged or bare areas.
- Bermuda grass has high fertilizer needs.
- Centipede grass is low maintenance and requires very little fertilizer.
Bermuda grass grows fast, stands up to use, and fills bare spots in your yard quickly because it is such a fast-spreading grass. Centipede grass, on the other hand, recovers slowly from damage because it is so slow-growing. While this might seem like an easy win for Bermuda grass, all that growth comes at a cost. Bermuda grass requires frequent fertilization to fuel growth, while Centipede grass is extremely low-maintenance.
How to Overseed Centipede Grass with Bermuda Seed
In order to overseed your Centipede lawn with Bermuda grass, follow these steps:
- Mow your lawn to 1–1.5 inches tall (2.5–4 cm).
- Dethatch the Centipede grass.
- Aerate the lawn with a core aerator.
- Spread 1/8–1/4 inch (3–6 mm) of compost on the lawn.
- Spread your Bermuda grass seed at bag rates.
- Rake the compost over the Bermuda seed to protect it.
- Water your lawn frequently to keep the seeds constantly moist for the first few weeks.
- Apply a lawn fertilizer to your yard.
- Wait 1–2 months after seeding to see the results of your overseeding.
- If Bermuda grass is growing well, spray a weed killer containing Quinclorac on the lawn. This will kill the Centipede grass and leave only Bermuda grass.
Because Bermuda grass and Centipede grass don’t grow well together when mixed, this method can be used to transition your lawn from Centipede grass to Bermuda grass. You won’t have to cut sod or live with a bare lawn. By overseeding Bermuda and then using a Quinclorac-based weed killer once the Bermuda has taken hold, you can seamlessly switch your lawn from Centipede to Bermuda through overseeding.