Turf Comparison: Zoysia vs St. Augustine Grass

Zoysia and St. Augustine both lead to thick, lush lawns with little room for weeds to grow. As far as warm-season grasses go, St. Augustine is an old standard and zoysia is gaining popularity. Whether you’re planning to create a whole new lawn or looking to improve what you already have, this article can help you make some tough decisions.

Comparing Zoysia vs St. Augustine Grass

While they have many similarities on the surface, zoysia grass vs St. Augustine is a comparison that deserves in-depth attention. When it comes to water, for example, one of these grass types will take far more than it needs. When it comes to maintenance, one of them requires far more frequent mowing and dethatching. Below you can learn all of the necessary differences between zoysia and St. Augustine grass.

Appearance

Zoysia has two features that stand out above all the rest: appearance and durability. If you have the right climate for it, zoysiagrass is an excellent deep, emerald green color. However, if it has received too much moisture or if the pH is too alkaline, that same fine-bladed grass will turn a sickly yellow-green. Aside from color, zoysiagrass is fine-bladed and soft to the touch.

St. Augustine, on the other hand, is also an attractive deep green. Though it has blades that are much coarser and almost “sharp” to the touch when short on water. Like Zoysia, St. Augustinegrass is slow to turn green after a period of cold has passed.

Best Uses for Zoysia Grass and St. Augustine Grass

The best place to plant zoysiagrass would be in a lawn with strong fences, borders, or walkways on all sides. Though this is an excellent grass type once established, it can be considered “invasive”, especially in the warmer regions like the Southern United States.

Ideally, this lawn would also have few if any trees, as zoysia does best when it has access to full sun. Traffic is negligible as zoysia produces such thick turf that few things would be capable of disturbing it.

St. Augustine is also considered invasive, though it spreads quickly in nearly any climate where it is capable of surviving the winter. Like zoysia, St. Augustinegrass prefers a spot with little to no shade, especially in a colder climate. In central Texas, however, St. Augustine could thrive with as little as 5 hours of direct sunlight a day.

Further, St. Augustine may have low irrigation requirements and can easily survive a short period of drought, but it takes up and disperses far more water than it needs. This could be fine if you have no flowers or bushes planted in or adjacent to your lawn, but it could lead to greater water consumption overall if your landscaping choices have to compete with themselves.

Soil Types and pH Needs of Zoysia Grass and St. Augustine Grass

Both St. Augustine and zoysiagrass have similar soil type and pH needs. First, they both need well-drained soil. Zoysia, however, still needs something with some organic matter or “richness” to it to establish quickly. St. Augustinegrass can grow in sandy soil. Neither of these grass types will tolerate wet or clay soils.

As for pH, both St. Augustine and zoysia prefer soil that is a little on the acidic side. A pH of 6 to 6.5 is ideal, but a neutral 7 is tolerable. Once you start getting to the alkaline side, you’ll notice that both zoysia lawns and St. Augustine lawns start looking a little straw-yellow or sickly. This can be corrected by acidifying the soil with no lasting damage to the turf.

Water Needs for Zoysia Grass vs St. Augustine Grass

Again, this is another example of why you might need a deep dive comparing Zoysia vs St. Augustine- both of these grass types have so much in common on the surface. Both zoysia and St. Augustine “should” get 1” of water per week. However, while zoysia grass will politely take what it needs, St. Augustine grass can be a bit greedy, absorbing as much as 2.5” if given the chance and taking this away from nearby plants.

Sun, Shade, and Temperature Requirements for Zoysia Grass and St. Augustine Grass

Both Zoysia and St. Augustine require full sun to thrive and will go dormant as temperatures fall below 55F. However, Zoysia vs St. Augustine shade tolerance is another matter. While zoysiagrass can handle very little if any partial shade in any climate, St. Augustine can handle just a few hours (4 to 6) of partial shade or 2 hours of full shade per day in the warmest climates, such as Southern Texas.

Durability of Zoysia Grass or St. Augustine Grass Lawns

St. Augustine lawns are susceptible to slow-healing damage from any type of traffic. Damaged blades do not heal smoothly or evenly and may develop grey or brown spots, rust, or appear burnt until they are completely grown out and mown off. This is a slow-to-heal and not particularly durable grass type when it comes to traffic. However, digging and root disturbances, if in a compatible sandy soil type, will cause little damage or disruption.

Zoysia grass is extremely durable once it is established. After the first three years, a zoysia grass lawn will become a bit of an impenetrable sheet during the growing season. Even cutting it with a dull mower or running over it with frequent, heavy traffic will hardly leave a mark and will not mar its color.

Common Pests and Diseases for Zoysia Grass Lawns and St. Augustine Grass Lawns

There is no clear winner between Zoysia grass vs St. Augustine grass when it comes to diseases or pests as they fall victim to almost identical ailments. Both are susceptible to all common lawn insects and highly susceptible to fungus infestations. If thatch is allowed to build up around zoysia, it will fall victim to mold and root rot. Standing water will do the same to St. Augustine lawns.

Mowing Needs of Zoysia Grass and St. Augustine Grass Lawns

Zoysia grass needs frequent mowing during the warm season and should be kept at a very short 1” height. This will inevitably lead to thatch that must be removed up to 4 times a year. St. Augustine grass should be cut to a height of 2 to 3”.

Types of Grass Related to Zoysia Grass

There are three types of zoysiagrass and all of them are sometimes referred to by this common name. However, the most common of these, “Zoysia japonica” is most likely what any lawn in the United States will contain. The other types, “Zoysia matrella” and “Zoysia tenufolia” are slower to grow and much less cold tolerant.

Types of Grass Related to St. Augustine Grass

There are few close relatives to St. Augustine, though it does have several cultivars that deal with specific issues. ‘Captiva’, for instance, increases the resistance of St. Augustine grass to the chinch bug. A variegated variety has also been produced, ‘Variegatum.’

Zoysia vs St. Augustine Cost

St. Augustine grass does not often produce seeds that are viable for long. Similarly, zoysia seeds are hard to keep viable during transportation and may even fail to germinate if the soil temperature they ultimately encounter is below 80F.

This means that the only way to start a St. Augustine or zoysiagrass lawn is to use plugs. These small grass starts are typically planted every 3, 6, or 12 inches. The farther apart they are, the longer they take to establish themselves but the fewer of them you need to buy.

Ultimately, this is how the cost will be determined. Further, you’ll need to consider transport costs for these hundreds of small plants. If you have local cultivators for both types of grass, the cost should be similar. However, given that zoysia takes more time to cultivate, you may find that it remains at a slightly higher price no matter the location.

The Best-Case-Scenario for a Zoysia Grass or St. Augustine Grass Lawn

Ideally, a zoysia lawn will have strong borders on all sides to prevent this grass type from overtaking any other landscaping or venturing into other lawns and wild areas. There will be no shade on the yard or, if there is, it should be indirect and intermittent. Lots of traffic and even pets living on the grass shouldn’t be a challenge.

A St. Augustine lawn should have similar barriers but can have a few more trees and bushes nearby. This is not an ideal grass type for much foot traffic or pets, so a low traffic spot or lawn is best. Plenty of drainage and rainfall is ideal if you want the best appearance for your St. Augustine lawn, too.

A Quick Summary of Zoysia Grass vs St. Augustine Grass

Below we’ve put together a top-level overview of the Zoysia Grass vs St. Augustine Grass comparison that you can quickly reference to see the differences between the two.

Grass Type	Zoysia Grass	St. Augustine Grass
Appearance	Deep Green with Smooth, Fine Blades	Low Growing with Broad, Dark Green, Thin, Coarse Blades
Popular Uses	Lawns Where It Can Be Well Contained – Fairways and Teeing Areas for Golf Courses	Low Traffic Lawns in Warm, Sunny Climates
Ideal Soil Type and pH	Well-Drained, Moist Soil is Ideal – 6 to 6.5 Ideal pH	Well-Drained, Poor, and Sandy Soil is Ideal – 6 to 7 Ideal pH
Water Requirements	1” of Water Per Week – Average Overall Water Consumption	1” of Water Per Week – Average Overall Water Consumption
Sun/Shade/Temperature Needs	Full Sun Necessary - Dormant at 55F	Full Sun Preferred, Can Tolerate Part Sun – Dormant at 55F
Durability	Excellent Durability and Damage Recovery Once Established	Mediocre Durability and Damage Recovery
Pests and Diseases	Fungus, Mildew, and Mold (Often Exacerbated by Thatch) – Beetles, Thrips, Grubs, Webworms	Beetles, Mole Crickets, Grubs, Nematodes, Chinch Bugs – Fungal Disease – Brown Patch – Root Rot
Mowing Needs	Should Be Mown to 1” Height – Dethatch Frequently (as often as 4x per year)	Mow to a 2” to 2.5” Height – Grows Fastest in Early Summer