Marathon Grass vs. St. Augustine: The Best Lawn Grass

Marathon and St. Augustine are popular grasses in warm-weather states like Florida and California. Although they’re both known for being durable, they can not be used interchangeably. 

The decision between Marathon grass vs. St. Augustine grass will come down to how you use your lawn and the climate where you live. Marathon Grass is the best choice for family yards because it holds up well to heavy foot traffic and is tolerant of cool weather, rain, and drought. St. Augustine is best suited for decorative lawns in coastal environments as it is tolerant to high humidity and salt and grows thick enough to choke out weeds.

Let’s dive into the pros and cons of each type of grass so you can make the best decision for your lawn!

Marathon Grass Seed

Marathon grass is a blend of two different fescue grasses: Hubbard 87 and Baja. It was developed in 1983 and has become a favorite of California homeowners for several reasons. This blend was designed for the diverse environment of the West Coast, with its mixture of forests and deserts.

Marathon grass is designed to stay green year-round and is hardy enough to handle heavy rain and drought. This hardiness makes Marathon grass somewhat coarse, so it’s not ideal for walking barefoot. But this coarseness also helps it hold up to lots of wear and tear from kids and dogs. 

Does Marathon Grass Need a Lot of Water?

Marathon grass is unique because it is most active in winter and dormant in the summer. It does need to be fertilized and watered regularly in the winter. 

Marathon grass has a unique deep root system that can be used to take in groundwater. These deep roots mean you have to water Marathon grass less than St. Augustine grass, which is also tolerant to heat!

Does Marathon Grass Stay Green All Year?

Grass in lawn
Marathon grass is attractive for homeowners in seasonal climates because it stays green all year long. This means your lawn will still look healthy and beautiful throughout winter.

One major concern with Marathon grass is dog urine. Due to their meat-heavy diet, dog urine contains high levels of nitrogen and salt. High concentrations of nitrogen burn grass, leaving brown patches behind. St. Augustine holds up better to dog urine than Marathon grass because of the two types of grass.

St. Augustine Sod

St. Augustine is a popular grass in places like Florida and the Gulf coast due to its heat tolerance. It also performs well in high humidity. St. Augustine is well-suited for Florida lawns because of its unique tolerance to salt. This grass can thrive in a wide variety of soil types. 

St. Augustine spreads quickly, so it’s an excellent choice for filling in patchy lawns. It has a lush blue-green color and a softer texture than Marathon grass. St. Augustine can be tricky to find in seed form because it grows unreliably, so garden centers usually sell St. Augustine sod instead. 

Will St. Augustine Grass Overtake Weeds?

St. Augustine is an aggressive grower, which makes it an apt choice for homeowners struggling with weeds. This grass is known to take over the yard, choking out unwanted shrubs and weeds. St. Augustine grows so thick that it prevents weeds from germinating, as they can’t penetrate the soil line. 

Is St. Augustine High Maintenance?

Because it is such a voracious grower, St. Augustine does have high fertilization and watering needs. In the summer, St. Augustine grass must be fertilized once every 6-8 weeks. St. Augustine requires more water than Marathon grass but is fairly drought-tolerant too. 

Keep in mind that St. Augustine grass does turn brown in the winter, as it’s not cold-tolerant like Marathon grass. Chinch bugs are also an issue for St. Augustine. Chinch bugs inject a toxin into the grass, which prevents it from drawing in water, killing the grass over time. Chinch bugs prefer dry grass, so keeping grass moist is essential to ward off infestations. 

Which Grass is Best for Your Lawn?

Deciding between Marathon grass or St Augustine will come down to how you use your lawn and the type of maintenance you’re prepared to do. 

Marathon grass holds up better to temperature changes and will stay green year-round. Although its texture is more coarse than St. Augustine, it also holds up better to foot traffic and pests. 

St. Augustine grass grows much quicker and easier than Marathon grass, so it’s a great solution if you want to fill in a patchy lawn. Due to its thick matted texture, it chokes out unwanted weeds for you. The downside is that such thick and quick-growing grass requires more regular fertilization and watering maintenance. St. Augustine grass is also susceptible to chinch bugs, who like to attack this grass once it dries out.

What is a Good Grass to Mix With St. Augustine?

In USDA growing zones 7-10, St. Augustine and Bermuda grass make an excellent duo. Both kinds of grass are suited for warm weather climates with high rain and humidity levels. Bermuda grass is not tolerant of shade, so mixing it with shade-tolerant St. Augustine will help make the grass hardier.

St. Augustine is usually installed as sod, whereas Bermuda grass can be planted as a seed. So if you want to fill in damaged areas of your St. Augustine grass without buying sod, you can overseed the area with Bermuda instead.

What’s the Difference Between Marathon 1 and Marathon 2 Grass?

Marathon grass comes in three different varieties: Marathon I, Marathon II, and Marathon III. Each offers different benefits depending on your needs. 

Marathon I

Marathon I is the original and most well-rounded variety of Marathon grass. It has a bright green color and is durable enough for year-round foot traffic. 

Marathon II

Marathon II is a denser and deeper green version of Marathon grass. This variety is designed to be more disease resistant than Marathon I. The tradeoff for this disease resistance is that Marathon II grows slower than Marathon I and therefore doesn’t hold up quite as well to foot traffic. 

Marathon III

Marathon III is the most visually attractive of these grasses, with a lush deep green color and thick texture. It grows the slowest out of all the Marathon varieties, which makes it better for decorative lawns rather than family backyards. Since this variety grows slowly, brown patches or damaged areas will show up more easily. 

What Kills St. Augustine Grass?

Your St. Augustine grass will turn brown and thin without proper watering and fertilization. Unfortunately, this type of grass is also prone to disease and pests.

St. Augustine is susceptible to a disease called brown patch. Brown patch is a fungus that thrives in high-humidity environments. The best solution to cure brown patch is to let your soil dry out and frequently mow your grass to remove the fungus. 

As mentioned before, chinch bugs are also a common issue for St. Augustine grass. They suck out the moisture from the grass and inject it with a toxin that causes it to brown. They dislike water, so heavy watering can help you get rid of these bugs. You can also use a pesticide. 

Although St. Augustine grass needs frequent fertilization, beware of using too much. High amounts of nitrogen can burn the grass and turn it yellow or brown. 


Marathon Grass is the best choice for family yards because it holds up well to heavy foot traffic and is versatile enough to be tolerant of cool weather, rain, and drought. St. Augustine is best suited for decorative lawns in coastal environments as it is tolerant to high humidity and salt.

Marathon also stays green year round, so it will keep your home looking beautiful throughout winter. St. Augustine grass is better equipped to handle high levels of moisture, humidity, and salt, so it’s preferable for environments like Florida. St. Augustine is an excellent choice if you don’t want the work of pulling weeds because it grows thick enough to choke out weeds. 

You can’t go wrong with either of these grasses; you just have to decide which variety offers the most benefit to you!