Two of the most popular choices of turf in warmer climates are Centipede grass and St. Augustine. They offer perfect aesthetics and durability for residential yard and commercial landscapes. Both have their benefits and will thrive in their environment if cared for properly. The issue is which one to chose for the project.
What is the difference between centipede grass and St. Augustine grass? The main differences between these grass types are their coloring, care, durability, and environment. Each is a different shade of green and requires differing levels of care, with centipede grass needing less. They also have different preferred environments with St. Augustine having more varieties.
They both have significant differences, but each comes with specific downsides and benefits. Some of these tend to overlap, like how both will spread over time and are easily contained even though they are aggressive. The popularity of each is also similar, and they are competitive in the market for lawns and landscaping.
Here is a quick and dirty side by side comparison of Centipede and St. Augustine Grasses for easy reference:
|Centipede Grass||St. Augustine Grass|
|Planting Options||Seed, Plug, Or Sod||Plug or Sod|
|Pest Threat||Nematodes and Grubs||Chinch Bugs|
Centipede grass, also known as Eremochloa buse, is a medium-textured, low growing grass that produces a dense and weed-free turf. It is an aggressively growing grass that is fairly attractive and requires little care.
- Centipede is more cold tolerant than St. Augustine grasses but has less shade tolerance. It requires at least 6 hours of sunlight each day to prevent it from dying.
- Even though it is aggressive, it is still easily contained as it only produces surface runners which are easily contained by bed liners.
- It can be planted either by seeds or sprigs and will flourish under good care. Centipede grass is very popular in sod farms and is easily obtainable.
- Although it requires less care and maintenance than St. Augustine grasses, Centipede grass does suffer from more and longer-lasting issues such as:
- Centipede decline
- Nutrient changes
- Pests (nematodes and grub bugs larvae)
Centipede Grass Decline
Centipede decline is one of the least understood issues that the grass may face, as it is not a disease. The decline is sometimes confused with other issues with the grass preventing its full recovery (source).
It is an issue that shows up in grass that is three years or older that results in large, yellowing patches of grass. These patches are weak and do not make it long.
These issues can be naturally occurring or possibly by negligence. The cause is usually poor yard maintenance such as:
- Too much or too little moisture
- Heavy thatch buildup
- Mowing height of less than 2 inches
Usually, the issue can be resolved by changing basic yard maintenance habits. Performing a soil test may also be beneficial.
Centipede grass is highly susceptible to changes in the nutrients available in the ground, specifically the acidity. Most of these changes can be measured and treated.
It prefers a more acidic soil that has an optimal pH level of 5.5. Anything lower or higher will cause yellowing and the possible deterioration of the grass. If your soil is alkaline, learn how to test and manage it.
Overall changes in nutrients may vary and are not limited to one type. Centipede grass can also suffer from:
- Too much of too little nitrogen
- Too much or too little phosphorus
- Low potassium levels
- Low iron levels
- Changes in pH levels
One of the most common situations is iron chlorosis, an iron deficiency in the grass. It results in either the entire yard or patches turning bright yellow.
Nematodes & Grub Bug Larvae
While it does not suffer from high sensitivity to chinch bugs, it does have an issue with nematodes.
Nematodes are either a small microscopic worm or little spherical scale insects. They are found in sandy soil and have no known treatments. The best approach to dealing with them is to ensure a hearty thriving lawn that is less susceptible to damage (source).
A less deadly situation is when the grass suffers from grub bugs. Theses are little white beetle larvae that feed on the roots of the grass.
Healthy lawns can withstand some grub bugs, but if the population grows too high, then treatment is required, or the lawn will suffer.
St. Augustine Grass
St. Augustine grass, also known as Stenotaphrum secundatum is a fine-textured grass similar to that of the Bermuda grass. The grass has wide, flat stems and broad coarse leaves in a blue-green color. When planted, it forms a deep and dense turf.
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- This grass is very shade tolerant and does not require much sun to thrive. It is still meant for warmer climates and does best on the south side of the equator.
- St. Augustine grass is not usually planted by seeds as it does not produce many viable seeds. It is mainly planted by vegetative means and spreads through the yard by long above-ground runners and stolons.
- The downside to this grass is that it is very sensitive to the chinch bug, which can quickly cause its death. Luckily, it can be controlled with insecticides, but frequent applications are required for maintenance.
Considering St. Augustine? Be sure to check out our St. Augustine Lawn Care Fertilizer Schedule (Free Printable)
Types of St. Augustine Grass
The most common types of St. Augustine grass are:
Considered an improved variety of the St. Augustine family, Bitter-blue has a denser and finer texture than the original with a mowing height of 3 inches to 4 inches. It also has a darker blue-green color than that commonly found in St. Augustine.
In comparison to the original, Bitter-blue has an improved cold tolerance and shade tolerance. It is still only an intermediate shade tolerance overall. It does have good salt tolerance and hot weather tolerance.
Bitter-blue still suffers from a sensitivity to chinch bugs and has a lower tolerance to atrazine, a chemical used in weed killers. This means that it is harder to prevent weeds from growing into a mixture of grass.
Another downside is that because of its low tolerance to atrazine; sod production farms will not usually produce it. Instead, they will produce Floratam, which is commonly confused with Bitter-blue.
Palmetto is a native St. Augustine grass that was chosen because of its better color and finer texture. It is a semi-dwarf grass that gives it a plush appearance without the risk of becoming thatchy.
The grass blade width of Palmetto is similar to that of Bitterblue but is finer than that of Floratam. Its leaf blades are tapered at the tip with a rounded end and are soft to the touch.
For the most part, when planted in the proper climate, Palmetto is an evergreen grass and can survive in colder climates as long as there are no hard frosts. After repeated hard frosts, Palmetto will become dormant.
This type has a very good drought tolerance; it will wilt like other types of St. Augustine grasses but will recover when water is applied. It also has better shade tolerance than most other varieties.
The main goal of the Floratum variety was to create a turf resistant to the SAD virus and chinch bug. The qualities originally did well in it but have since weakened, and chinch bugs are now a major problem.
Floratum has a coarse texture and has wider and longer leaf blades than most other varieties. The signature sign of the Floratum is the large, purplish-red color of their stolons with internodes of approximately 3 inches in length.
This variety is not as cold tolerant as the common St. Augustine and will suffer freeze damage whenever the temperature falls below freezing for long periods of time.
Floratum is very fast-growing and spreading and can extend stolons up to ¾ of an inch per day, but it has a mowing height of around 1 inch.
Will St. Augustine Choke Out Centipede?
A question that I’m asked often is if you have both types of grass in your yard, which one will take over. I’ve tested multiple times in my yard and, to be honest, it’s a little bit of a crapshoot. St. Augustine will spread it’s runners wide and begin spreading into the Centipede but if the Centipede grass is healthy, it’ll grow into the St. Augustine grass just as aggressively.
I have test areas in my yard where I planted St. Augustine over two years ago and those patches are still pretty much contained by the surrounding centipede. Neither has been “choked out” by the other. They fight for ownership of territory but there is no clear winner. For now, it’s a draw.
You may also want to read Will St. Augustine Take Over Bermuda Grass?
I’ve had lawns with both Centipede and St. Augustine and in the southern states, they each do really well. I’ve become partial to centipede over the last decade mainly because it is a lower growing grass that does not require mowing with the same frequency as St. Augustine.
Additionally, because I usually have at least an acre or two of land, I don’t want to deal with the hassle or cost of sodding an entire yard. I can seed with centipede relatively inexpensively.
Whichever option you choose, it comes down to as much personal preference as anything else. There are pros and cons to each grass type but in the southern states both Centipede and St. Augustine are commonly seen thriving in yards everywhere.
Be sure to check out our other lawn articles for everything from preparing your soil for grass seeds to fertilizing and aeration.