St. Augustine grass (Stenotaphrum secundatum), a type of turfgrass prized by coastal homes for its high tolerance to heat and humidity, is a relatively simple lawn grass to grow. It has a dense turf that establishes quickly and can withstand many elemental circumstances.
Of course, you can use specific tactics to make your St. Augustine lawn grass grow faster and healthier and encourage it to spread widely to uncovered areas.
Read on to learn how to make St. Augustine grass spread quickly!
Understanding How St. Augustine Grass Grows
If you want to select St. Augustine for your lawn grass, you will need to make sure that you live in a region with the climate factors it needs to make this versatile beauty shine. It thrives in warm, tropical temperatures and can flourish on both sides of the Atlantic Ocean.
A reliable maintenance schedule for St. Augustine is the best way to ensure its proper growth and care. While St. Augustine is relatively low maintenance, it’s essential to understand how certain factors can make or break the life cycle of this lawn grass.
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Regional Climates and St. Augustine Grass
One of the biggest draws to St. Augustine is its durability when confronted by the elements. Especially in the case of salt from ocean spray, this lawn grass is a hardy survivalist. It’s also very tolerant of foot traffic and changes in rainfall patterns and grows well in both full suns and in light shade. For this reason, it’s cultivated primarily for use in coastal environments.
Lagoons, marshes, and shorelines will see a lot of St. Augustine that naturally occurs since it’s happiest in moist environments. Both tropical and subtropical weathered climes, such as the Caribbean and Mediterranean, support this varietal very well.
St. Augustine is also a prime choice for pasture and ranch grass. It is sturdy and nutrient-dense and therefore ideal for livestock to consume when grazing.
St. Augustine Ideal Soil Conditions
While hardy, St. Augustine grass cannot consistently tolerate badly waterlogged soil (since this reduces its oxygen too significantly) or compacted soil (meaning that porosity and room for new growth will be adversely affected).
Here are some factors that will positively impact growth and outline the ideal soil for this grass.
Soil Type
The soil used for your St. Augustine grass should be well-aerated and compaction-resistant, like sandy soil. Make sure it’s a type of soil that drains efficiently, like sandy loam soil. As for topsoil in more sparse areas, similar guidelines apply – go for loose, free-flowing sandy soil, or sandy loam.
Remember that you can always have your soil professionally tested or pick up a do-it-yourself soil testing kit at your nearest landscaping or home improvement store.
These results will tell you about any soil issues inherent in your current environment, and whether or not to consequently increase or reduce acidity.
Soil pH
pH balance, or potential hydrogen balance, is a figure that expresses the acidity or alkalinity of your soil or the environment. Most lawn grasses grow best with a mid-acid range balance, which is why lawns can be harmed after heavy rain which washes valuable nutrients away and causes a lawn to become too acidic.
St. Augustine thrives and propagates in a slightly acidic soil pH. Generally, this pH should be between 5.0 and 8.5 in value.
Bear in mind that sulfur or lime can be applied to soil to raise its pH and lower its acidity to an acceptable level. And again, don’t be afraid to get your soil professionally tested for any possible improvements, or pick up a soil testing kit to perform yourself at home!
Dormancy
St. Augustine grass will naturally go dormant with seasonal changes like frost since this grass grows best in temperatures between 80 to 100 degrees Fahrenheit.
Be sure to plant St. Augustine during the spring or summer, or if your region expects a frost, at least 90 days before that date. This is so that St. Augustine has time to establish before the cold weather arrives to halt further growth.
As a general rule, this grass will thrive as long as its soil is 60 degrees or higher. If the soil temperature drops below 55 degrees, St. Augustine will become dormant and lose its vibrant color, only to re-liven when the weather warms again.
St. Augustine commonly stays green and vivacious all year round in climates that never drop far below spring and summer temperatures. This makes it a staple of Florida and Texas lawns, for example.
St. Augustine Grass Growth Rate
This grass grows rapidly when given appropriate water and space. Once St. Augustine is planted and has started to grow, it will take about 7 to 14 days for it to begin to spread.
You can expect full coverage of the desired area within one growing season, with proper spacing of plugs or sod.
If, for some reason, the growth rate does not adhere to this timeline, consider having the soil professionally tested to ensure suitable aeration and alkalinity. However, under normal conditions St. Augustine will establish and spread relatively quickly in comparison to other grass varieties, providing you with thick and lush coverage.
How Does St. Augustine Grass Spread
St. Augustine spreads by the use of its stolons. Stolons are horizontal growth shoots that develop and spread simultaneously as the grass is establishing growth.
For this reason, St. Augustine is a solid choice for those seeking to optimize both thick, lush growth and high spread of lawn coverage in as little time as possible.
Rhizomes Vs Stolons
Whereas other grasses, like Bermuda grass, rely heavily on rhizomes for their vegetative reproduction, St. Augustine grass spread quickly with the help of stolons.
Rhizomes are short and thick, growing underground as part of the main plant stem. Stolons are creeper parts of the plant that grow aboveground to establish coverage more efficiently than Rhizomes and do not rely on a primary root system to survive.
Instead, stolons create new roots as they spread, bringing vegetative independence and strong coverage to the desired area.
The stolons present in St. Augustine grass are key in making it spread quickly and over large areas, and this is why the protection and encouragement of this part of the plant are so important.
Making St. Augustine Grass Thicker and Spread Faster
When I’m growing or maintaining a St. Augustine lawn, there are a few rules I adhere to to ensure thick and lush growth:
Remove Thatch Build Up
Thatch is a naturally occurring layer of dead plant material, comprised mainly of dead leaves, old grass clippings, and other plant matter. If not addressed, a thatch layer can settle on your lawn and choke new growth.
It’s crucial to note that dethatching a St. Augustine lawn is best done by hand rake and not by power tools. If you sink too deep into the top layer of soil, you risk destabilizing the structural integrity of the lawn.
This is also because a thin layer of thatch – about half an inch thick – is nutritionally beneficial to a lawn, helping it retain moisture and discourage weeds. It’s possible to become overzealous in your dethatching, and therefore I advise careful consideration of timing and depth when dethatching St. Augustine.
The other factor to consider is the aforementioned stolons of the grass. If you’re not careful in the dethatching process, you could accidentally tear up stolon systems, severely hampering growth and spread.
Always wait for your lawn’s active growing season to commence before dethatching. St. Augustine should have thawed thoroughly and had a chance to begin new growth before dethatching begins for the season.
Be sure to water and fertilize after dethatching to ensure that healthy growth continues!
Aerating the Soil
You should aerate a St. Augustine lawn no more than twice a year; once is recommended unless you live in a hot and humid area where the soil has become highly compacted. This aeration should occur at the height of growth, usually at the beginning of summer.
Rent a hollow-tined aerator to provide your lawn with the best access to protection from drought and disease. This machine will puncture the earth and remove “plugs” of soil, leaving more room for oxygen, hydration, and deeper, more thorough root systems.
Don’t use a solid-tined aerator. These machines poke holes deep into the soil without leaving the necessary room for hydration and oxygen and, therefore, can damage a lawn long-term.
Deep Watering
While it’s certainly possible to overwater St. Augustine grass, you should begin by observing rainfall and weather patterns. In climates where rainfall is scarce during a growing season, watch for dry or curling grass that may be losing color to gauge the appropriate frequency of deep watering.
St. Augustine grows best when given about a six-inch layer of moisture in its soil. In many areas, this means that you should water your St. Augustine lawn approximately twice a week.
Again, watch for visual signs of overwatering (soggy grass or fungus development) and underwatering (grass that has become brittle and gray or brown in color).
High Phosphorus Fertilizing
St. Augustine grass requires both high phosphorus and high nitrogen fertilizer to ensure the best rapid growth, optimal thickness, and strong color.
Use a high-phosphorus fertilizer every 6 to 8 weeks during a growing season for a hardy and disease-resistant St. Augustine lawn.
Mowing
Frequent mowing – about once a week during peak growing times – is essential to developing a healthy turfgrass like St. Augustine. Set the mowing height to about 2.5 to 3 inches.
Mowing too far down to the shoots will provoke halted growth and slow spread. Be careful to mow at a set length and to mow regularly.
Weed Management
Select an herbicide for your St. Augustine lawn that is as natural as possible while still providing full-spectrum protection against broadleaf weeds.
Both pre-emergent and post-emergent herbicides are available to buy in a selective weed-killer format. This means they will preserve your lawn whilst eliminating weeds or weed seeds from either appearing in the first place or from growing too extensively once they have emerged and before they get out of control!
How Long for St. Augustine Grass to Spread
St. Augustine grass, once correctly planted and established, shouldn’t take more than 7 to 14 days to begin an aggressive spread.
To take full advantage of this fast growth, plant in the early spring or summer and fertilize regularly.
Fixing Patches in St. Augustine Grass
Patches in St. Augustine grass lawns are chiefly due to watering frequency – they typically mean that a lawn is being either overwatered or underwatered. To address this issue, purchase a patch-covering spray or lawn treatment, or implement the use of grass plugs or grass seeds to encourage new growth. Once treated, apply a layer of topsoil over the affected area to help root establishment and spread.
Seeding St. Augustine
If you’re looking to re-enliven a patch of St. Augustine on your lawn, I recommend that you reseed the area. Do this in the earliest part of the growing season and only when there are areas of patchy or sparse growth.
St. Augustine Sod
You should aim to lay St. Augustine sod for initial growth in the spring or early summer. Sod should always be placed at least 90 days before the first estimated frost for your region, and the more time it has to establish, the better!
Sod is also helpful for covering unsightly patches or breakages in pattern growth in your lawn. Lay new sod in the problem area to encourage growth and connection outward.
St. Augustine Grass Plugs
Grass plugs for St. Augustine are another way to revitalize your lawn. Grass plugs are a fast and significantly cheaper way to cover bare patches of lawn.
These plugs can be obtained and implemented at the height of the growing season, making them a quick and visually appealing option for coverage.
FAQ How to Make St. Augustine Grass Spread Quickly
Take a look at one of the most commonly asked questions regarding how St. Augustine grass grows:
Final Thoughts
St. Augustine grass is a fantastic choice for fast-spreading, lush, and gorgeously hued lawn grass. Best of all, any pitfalls in the growth of this grass are soon rectified, making it a stress-free and wonderful grass for warmer and more humid residential climates.
