St. Augustine grass and centipede grass are two of the most common warm-season grasses. They are great for homes and business premises. They have subtle differences that might influence your choices on what to grow.
St Augustine grass and Centipede grass can be differentiated through;
- Physical appearance
- Maintenance requirements
- Propagation methods
Still, you can mix these two turfgrasses for a lawn with improved shade tolerance and winter hardiness.
We pit these grasses against each other and help you make a better choice for your lawn.
What is St Augustine grass?
St. Augustine grass (Stenotaphrum secundatum) is a warm-season turfgrass variety with a beautiful medium-dark green shade. It has a stoloniferous growth habit. It spreads via lateral, above-ground runners called ‘stolons.’ Meanwhile, the leaf blade is wide, flat, and coarse-textured.
St. Augustine grass thrives in humid climates and can survive in different soils. However, it has the lowest cold tolerance of all the common warm-season turfgrasses, turning brown early in the fall and not greening until late into the next spring.
St. Augustine grass forms a smooth, compact turf. It retains its color longer into the winter than other warm-season turfgrasses. St. Augustine grass is also relatively low maintenance, as it only needs infrequent mowing. Furthermore, it has excellent tolerance for low moisture conditions.
Due to its superior heat resilience, St. Augustine grass barely goes dormant. It retains its color even during summer. It can thrive in temperatures of up to 90-degrees Fahrenheit. However, St. Augustine grass needs to be watered consistently without being left to dry out totally.
Note: Compared to a smooth-textured grass like Zoysia, coarse-textured turfs like St. Augustine are great at covering up unsightly weeds that may creep up on the lawn.
What is Centipede Grass?
Centipede grass (Eremochloa ophiuroides) is a warm-season perennial turfgrass. It has a creeping growth habit and spreads via stolons (above-ground, lateral runners). You can easily identify centipede grass via the light-green leaf blade, which is boat-shaped and has a rounded tip and a prominent, white mid-vein.
The leaf blades measure 15-30mm in length and are 2-5mm wide. Meanwhile, the flower seed-head is a single, 3-5 inch spike that’s purple-colored. Centipede grass has folded vernation and a membranous ligule. Meanwhile, the leaf blade attaches directly to the leaf sheath since it lacks auricles.
Centipede grass has excellent heat tolerance and moderate shade tolerance. It’s also slow to form thatch and can stay green through the winter without going dormant. On the downside, though, centipede grass has low salt tolerance and doesn’t do well in heavy foot traffic areas.
In terms of maintenance requirements, Centipede grass is the slowest-growing of all common warm-season turfgrass varieties, thus requiring infrequent mowing. Keep your mowing height to 1-2 inches for a robust and healthy centipede turf.
Additionally, apply 1-2lbs of Phosphorus-free 15-0-15 fertilizer per 1000 square feet annually.
Centipede Vs. St Augustine
There are many similarities between Centipede grass and St. Augustine grass. Both are warm-season perennials with high heat and drought tolerance.
However, these two turfgrass varieties vary in physical appearance, sunlight requirements, temperature requirements, and maintenance requirements. There are also slight differences in propagation methods and root systems.
Here is a summary table for differences between St. Augustine and Centipede grasses
|St. Augustine grass||Centipede grass|
|Leaf-blade is medium-dark green, boat-shaped at the tip. Blades are opposite each other.||Leaf-blade is apple green, v-shaped at the tip. Blades alternate at the nodes.|
|Great shade tolerance||Moderate shade tolerance|
|Better heat tolerance than centipede grass||Better cold tolerance than St. Augustine grass|
|Has deeper roots (at least 6-inches deep)||Has shallow roots (concentrated within top 4 inches of the soil)|
|It can be established through sods and plugs||It can be established via seed|
|Requires more water and fertilizer than Centipede||Requires less water and fertilizer compared to St. Augustine|
Centipede grass leaf blades have V-shaped, flat tips, while St. Augustine grass blades have boat-shaped tips. Also, centipede grass blades are light green compared to St. Augustine’s medium-dark green blades.
Finally, centipede grass leaf blades have an alternating pattern on the stalk, whereas St. Augustine leaf blades lie directly opposite each other.
Sunlight Requirements/ Shade Tolerance
Both of these warm-season turfgrasses prefer full sunlight. However, St. Augustine grass is the more shade-tolerant of the two and can be successfully grown in heavily-shaded lawns. Centipede grass is likely to wither and die in partially-shaded lawns.
Centipede grass and St. Augustine are warm-season grasses and will thrive in lawns in the South, where summers are hot and winters are mild. However, St. Augustine grass is the more heat-tolerant of the two; and doesn’t typically go dormant in the summer unless temperatures exceed 100-degrees Fahrenheit.
Meanwhile, centipede grass beats St. Augustine grass in cold tolerance. While the latter will likely go dormant early in the cool season, centipede grass tends to stay green in places where winters are mild.
Growth Habit/ Roots
St. Augustine grass and centipede grass both grow via stolons. However, St. Augustine stolons form deeper roots, growing at least 6-inches deep into the soil. By contrast, centipede grass stolons are shallow-rooted by nature, with most of the root mass occurring within the top four inches of the soil.
Seeds/ Propagation Methods
Centipede grass grows to produce flower spikes (racemes) that yield seeds eventually. As such, you can establish this type of turf via seed, sod, or plugs. Its seeds are slow to germinate, typically taking anywhere between 10 and 28 days to sprout.
Comparatively, St. Augustine grass barely produces enough viable seeds for commercialization, with some cultivars even being sterile. St. Augustine lawns are primarily established via vegetative propagation (sods and plugs).
Water: Centipede grass is a shallow-rooted turfgrass. Watering it too often won’t make the roots grow deeper. Irrigate it only when it starts to show signs of wilting or discoloration. On the contrary, St. Augustine grass requires deep, consistent irrigation (every 3-6 days) for deeper rooting.
Mowing height: Centipede grass is best kept at 1.5-2 inches long to maintain its health. Comparatively, you should mow St. Augustine lawns up to 2.5-4 inches long.
Fertilizer: St. Augustine grass needs more Nitrogen fertilizer than centipede grass to stay healthy and naturally choke out weeds. A centipede lawn only needs 2 pounds of Nitrogen fertilizer per 1000 square feet annually. By comparison, St. Augustine grass needs up to 4 pounds of nitrogen fertilizer per 1000 square feet annually.
Pros of Centipede Grass
Here are some advantages of having a centipede grass lawn;
Centipede grass requires minimal maintenance
Centipede grass is a slow-growing, low-growing grass hence doesn’t need to be mowed often. What’s more, it only needs to be irrigated when it starts to show signs of moisture stress.
Centipede grass is weed-resistant
Centipede grass forms thick turf. A high turf density enables it to crowd out weeds easily.
Centipede grass is heat-tolerant
Centipede grass stays green in hot weather conditions, making it a suitable turfgrass option for southern lawns that typically experience sweltering summers.
Cons of Centipede grass
Here are some drawbacks of centipede grass lawn;
It’s prone to Centipede decline.
Centipede decline is a unique condition whereby centipede grass slowly deteriorates, developing large discoloration patches by mid-summer. It’s commonly caused by improper mowing, improper fertilizer application, and excessive thatch buildup.
Centipede grass has low shade tolerance.
Despite having moderate tolerance for lightly shaded conditions, centipede grass is averse to heavy shade. Heavy shade increases the likelihood of grass mortality.
Centipede grass has low traffic tolerance.
Centipede grass is best for lawns that receive light traffic and will not withstand heavy traffic due to its slow growth rate when trying to recover from wear.
Pros of St. Augustine Grass
Here are some advantages of St. Augustine grass lawn
St. Augustine Grass has excellent shade tolerance.
St. Augustine grass can thrive in shaded lawns despite preferring full sunlight conditions.
St. Augustine Grass forms a dense turf.
St. Augustine grass forms dense grass that can choke out weeds.
St. Augustine Grass greens up early.
St. Augustine grass comes out of dormancy early in the growing season (late winter- early spring).
Cons of St. Augustine Grass
Here are some disadvantages of St. Augustine grass lawn
St. Augustine grass has poor cold tolerance
St. Augustine grass has poor cold-hardiness compared to common warm-season grasses. It goes dormant early in the fall.
St. Augustine grass can only be propagated vegetatively
St. Augustine lawns can’t be established from seed.
St. Augustine grass is vulnerable to pests.
St. Augustine grass is vulnerable to several pests, with chinch bugs being the most common.
Can you mix Centipede and St Augustine Grass?
You can successfully mix centipede and St. Augustine grass on your lawn. St. Augustine grass has better shade tolerance than centipede grass. Meanwhile, centipede grass keeps the lawn green in the winter when St. Augustine goes dormant. As such, mixing the two on a shaded lawn results in a healthier turf that stays green all year round.
Also, to successfully mix these two turfgrasses, you’ll have to maintain the soil pH between 6.0-6.5. While centipede grass will still thrive in low fertility soils with pH levels as low as 5.0, St. Augustine grass is likely to die back if the soil pH drops below 6.0. To raise your lawn soil pH, add some lime.
Fertilizing a mixture of Centipede and St. Augustine grass may be a headache. St Augustine grass is a sucker for Nitrogen fertilizer, while Centipede thrives just fine in low-nitrogen soil. While technically you can mix the two, the difference in fertilization protocol might yield undesirable results.
One of the biggest challenges when mixing these two turfgrass varieties lies in the propagation stage, as you can only establish a St. Augustine turf via sodding or plugging. Meanwhile, centipede grass can be established via seed, sod, and plugs.
Will centipede grass take over St Augustine?
Centipede grass will not choke out St. Augustine grass when grown on the same turf. Both of these grasses spread via stolons, with either of them being just as aggressive as the other. What’s more, centipede grass is slow-growing and takes time to fill in, by which time St. Augustine grass will already be deeply-rooted.
i. Richard L. Duble, turfgrass Specialist- Texas Cooperative Extension: Centipede Decline
ii. Grady Miller, Crop & Soil Sciences Department- North Carolina State University Extension: Centipede Grass