Best Fertilizer For St Augustine Grass (2022)

Selecting the perfect turfgrass for your front or backyard is always a big decision, especially with the wide variety of grass types available to gardeners and landscapers.

But among the available turf options, St. Augustine grass is a favorite due to its robustness, growth rate, and ease of maintenance.

Keeping your lawn green and leafy is made much easier with St. Augustine grass. It is a densely growing turf that can thrive in nearly all types of soils, in extreme summer temperatures, and can even hold its own against some of the lower ranges of cooler weather.


  • Noticeable effects after just one application
  • Swift weed killing action
  • Propagates St. Augustine grass while killing grassy weeds
  • Great value for treatment area
  • Able to be applied during any season
  • Ready-to-use mixture, just add to a spreader
  • Easy-to-use coverage calculations
  • Money-back guarantee
  • Successful lawn insecticide

Best Fertilizer For St Augustine Grass: Top 7 Picks

Scotts Southern Turf Builder
Specially formulated product for Southern lawns, providing even distribution of nutrients with every applying. It feeds any grass type and improves the lawn's ability to absorb nutrients and water.
Scotts Turf Builder Bonus S
Creates strong grass roots to help against heat and drought, feeding them to prevent future weeds creation. It kills the already present clover, dollarweed, and other lawn weeds.
Scotts Turf Builder Southern Triple Action
Not only prevents and kills invasive weed species, but also stops any insect infestations. The protection lasts up to 6 months with one application. Helps with building thick and green lawns.
Scotts EZ Patch Lawn Repair
Lawn repairs are 60% faster with this fertilizer, by absorbing six times its weight in water, allowing the seed a moist protective layer. The results are visible within 15 days of the application.
Simple Lawn Solutions Maximum Green & Growth
All grass types will result in vigorous green growth, having a healthy supply of liquid nutrients, quickly and easily applied. Each application will perk up the lawn and enhance the existing minerals.
Scotts Green MAX Lawn Food
The fertilizer regularly feeds your lawn by providing essential nutrients needed to withstand all types of weather activity. It helps to provide deep greening of any type of grass in only 3 days.
BioAdvanced 3 In 1 Weed And Feed For Southern Lawns
The 3 in 1 formula helps to provide essential nutrients for strengthening your lawn, containing slow-release fertilizer for long-lasting feeding. Prevents emerging of broadleaf and grassy weeds for up to 6 months after applying.

St. Augustine grass is not immune to all environmental or foot traffic woes that can impact it.

Gardeners who wish to keep it propagated healthily and well-maintained should keep themselves stocked with the appropriate fertilizers that will encourage the growth and greenness of their St. Augustine grass.

Read on to learn about the top products on the market for any gardeners looking for the best fertilizer for St. Augustine grass, and keep your lawn looking full and luscious all year round.

1. Scotts Southern Turf Builder — Best Fertilizer

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Style: All-in-one nitrogen fertilizer particles

Application: Broadcast spreader or drop spreader

Size: 28.12 pounds

Treatment Area: 10,000 sq. feet

With a special formula designed for Southern lawns that works to protect your grass against heat and drought, Scotts Turf Builder is great for all grass types, including St. Augustine grass.

This fertilizer is an easily applied all-in-one treatment that encourages your lawn to absorb water and nutrients naturally. Scotts Turf Builder works to support stronger root growth that will give your lawn a longer life span and a denser consistency that is good for preventing weeds.

With regular feedings, your St. Augustine grass will look better than ever, and be strengthened against weather, weeds, and foot traffic, so it is ideal for any family-use areas. According to users, Scotts Turf Builder is one of the best fertilizers for St. Augustine grass.


  • Ready-to-use mixture, just add to a spreader
  • Great value for treatment area
  • Able to be applied during any season
  • Safe to re-enter lawn directly after application


  • Can cause damage to your lawn if it’s in bad shape already
  • Not for use on Northern lawns

2. Scotts Turf Builder Bonus S  — Runner Up

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Style: All-in-one nitrogen fertilizer particles

Application: Broadcast spreader, drop spreader, or hand-powered spreader

Size: 17.24 pounds

Treatment Area: 5,000 sq. feet

Support your lawn’s health and growth while combating common weeds with Scotts Turf Builder Bonus S. This fertilizer product works great on Southern lawns that are composed of St. Augustine grass, zoysia, and carpetgrass, among others.

The specialized formula encourages grass growth and density to crowd out weeds that appear, simultaneously killing lawn weeds like clover and dollarweed. Once the weeds desiccate, you can easily rake them out of your lawn and leave a fresh, green canvas behind.

Applying Scotts Turf Builder Bonus S to your St. Augustine lawn will leave it a deep and long-lasting green that remains healthy during all upcoming seasons.

Regular applications help your grass remain strong and virile even with common environmental stressors, such as drought, heat, and the constant impact of being in a high-traffic area.


  • Propagates St. Augustine grass while killing grassy weeds
  • Noticeable effects after just one application
  • Swift weed killing action


  • Only works on specific grass types
  • Only for when the grass is green and growing

3. Scotts Turf Builder Southern Triple Action — Best For Pests

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Style: All-in-one nitrogen fertilizer particles

Application: Broadcast spreader, drop spreader, or hand-powered spreader

Size: 27 pounds

Treatment Area: 8,000 sq. feet

A great option if your yard is plagued by a variety of weeds and pests, Scotts Turf Builder Southern Triple Action works to encourage healthy grass growth for St. Augustine grass, as well as centipedegrass, carpetgrass, and zoysia.

While promoting thick, green lawn propagation, this easy-to-use fertilizer uses a mixture of nitrogen and atrazine to tackle invasive weed growth and common garden pests that can hinder or even harm your lawn.

Application of this fertilizer can prevent and kill common weeds like clover, oxalis, and henbit, as well as pesky critters like fire ants, ticks, mole crickets, and sod webworms for up to six months. Apply on your lawn when it is dry and insects are visible.

The 3-in-1 formula targets weeds and insects while strengthening the surrounding lawn to further prevent them in later months, and is best used in combination with a surrounding fertilizer and lawn care routine for overall coverage.

If your yard is plagued by little critters and stubborn weeds, this product might just be the best fertilizer for St. Augustine grass under those circumstances.


  • Easy-to-use coverage calculations with the Scotts My Lawn app
  • Money-back guarantee
  • Successful lawn insecticide


  • Season-specific, so lacking in year-round coverage
  • Not for use on Northern lawns

4. Scotts EZ Patch Lawn Repair

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Style: Ready-to-use lawn repair mix

Application: Apply directly from the jug

Size: 3.75 pounds

Treatment Area: 85 sq. feet

Repair and treat your St. Augustine lawn easily with Scotts EZ Patch formula.

Unlike other grass repair mixes that rely on grass seeds to supplement bald patches in your lawn, Scotts EZ Patch Lawn Repair is a combination of fertilizer and mulch that acts fast to propagate new lawn growth and protect it from weeds and weather.

With mulch that can absorb up to six times its own weight in water, your new grass growth will be safe below a protective cushion of mulch that dispenses only necessary moisture, while keeping the individual plants surrounded and safe.

And because St. Augustine grass thrives when given the proper amount of fertilizer, you don’t have to worry about measuring or reapplying any mixtures.

Scotts EZ Patch Lawn Repair contains a special controlled-release fertilizer that feeds and enriches your St. Augustine grass over a safe and sustainable period.

To apply this easy-to-use product, identify the problem patches where your St. Augustine grass is lacking, shake the product onto the area, and gently water it in. The EZ Patch should be saturated, but not holding pools of water.


  • Visible results after just 14 days
  • Can fill and regrow large patches of your lawn
  • Great value as only small amounts of product are needed
  • Targets specific areas along sidewalks or driveways


  • Problem areas need frequent and consistent watering after the product is applied
  • Does not include grass seed for immediate plugging

5. Simple Lawn Solutions Maximum Green & Growth

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Style: Liquid fertilizer concentrate

Application: Garden hose attachment

Size: 32 ounces

Treatment Area: 5,000 sq. feet

With this high-nitrogen lawn supplement, your St. Augustine grass will never look better. Stimulate growth, keep it green, and prevent nutrient deficiency with this control-release formula.

With both fast and slow release times, your lawn will immediately get 70% of the nitrogen supplements to encourage growth in the short term. Over time, the remaining 30% of supplements will seep into the soil, ensuring your lawn remains fed and healthy.

The Simple Lawn Solutions Maximum Green & Growth product is great for a variety of lawn turfs, including St. Augustine, buffalo, fescue, ryegrass, and zoysia. Expect vigorous plant growth after application as your lawn thrives on the extra nutrients.

Gardeners can consistently rely on this product as the best liquid fertilizer for St. Augustine turfgrass lawns.


  • Great for all grass types
  • Fast solution for nitrogen depleted yards
  • Effective on pet pee spots
  • Visible results after one or two applications


  • Not pet-friendly as it can cause an upset stomach
  • A lot of the product is required for applications

6. Scotts Green MAX Lawn Food

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Style: All-in-one nitrogen fertilizer particles

Application: Broadcast spreader, drop spreader, or hand-powered spreader

Size: 33.33 pounds

Treatment Area: 10,000 sq. feet

Rely on Scotts Green MAX Lawn Food for a deep green lawn in days. This easy-to-apply, multi-level formula is ideal for any grass type, including St. Augustine grass.

With each application dispensing iron and nitrogen to your lawn, these micronutrients work to speed up the greening process and enhance the health of existing root structures, giving your grass a better hold on the soil for better traffic resistance.

Scotts Green MAX Lawn Food is unique because each fertilizer granule is all food, and no filler—meaning that your lawn gets 100% of the nutrients this fertilizer carries without excess chemical barriers to breakdown.

And with spectacular coverage included in each bag, this product will keep your lawn long and luscious for many seasons to come, especially when used as part of a Scotts lawn care plan with other appropriate products.


  • Visibly greener grass within three to fourteen days
  • Does not stain when used correctly
  • Lawn safe to enter immediately after application
  • Great for any grass type
  • For use in spring, summer, and fall months for full coverage


  • Improper application can lead to sod burns
  • A lot of the product is required for applications

7. BioAdvanced 3 In 1 Weed And Feed For Southern Lawns

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Style: All-in-one nitrogen fertilizer particles

Application: Broadcast spreader, drop spreader, or hand-powered spreader

Size: 12.5 pounds

Treatment Area: 5,000 sq. feet

If your Southern lawn is plagued by weeds such as dandelion, clover, and henbit, or rampant with invasive broadleaf grasses like dollarweed and chickweed, this could be a good product for you.

Ideal for application in the early spring or fall, your grass will be protected year-round when this fertilizer is used routinely—especially if you have a St. Augustine grass lawn of any variety, including Floratam.

BioAdvanced’s 3 in 1 Weed and Feed is true to its name, tackling the invasive plants that threaten your lawn while simultaneously nurturing the turfgrass and encouraging healthy growth.

With only one application, you can protect your yard from weeds and unwanted broadleaf plants for up to six months without harming the surrounding turfgrass.

Active ingredients include dicamba acid, penoxsulam, and indaziflam for a balanced treatment and nutrient combination. It should be applied only on Southern lawns when weeds are actively growing, with temperatures between 50 and 90℉.


  • Easy application process
  • Offers six-month protection from weeds
  • The fertilizer formula includes a three-month slow release
  • Does not harm lawns when used according to the instructions
  • Good value for money
  • NPK of 35-0-3
  • Combats a variety of weeds during the spring and summer months


  • Not for use on Northern lawns
  • Product dissolution process can be slow
  • Fertilizer can clump together when put in the spreader
  • Not safe for people or pets to enter the lawn directly after application


Among other types of turfgrass popular among gardeners and landscapers, St. Augustine grass is not the most delicate, but it’s not the hardiest either. Which is why choosing the best fertilizer for St. Augustine grass is essential!

St. Augustine grass exists in the liminal state of being a robust grass that does require some tending to grow as effectively as possible.

With that being said, it’s worthwhile to discuss some of the most common queries that people have about St. Augustine grass, such as how to keep it growing well, among others.

Read on for all the dirt on St. Augustine grass!

fertilize your lawn FAQ

How Do I Make My St. Augustine Grass Thicker?

It’s important to ensure that your St. Augustine grass is healthy to encourage thick, dense growth. Keep the turfgrass well-fertilized over the spring and summer with phosphorus and nitrogen mixtures that will propagate better root growth and stolon coverage.

Any new St. Augustine sod that is laid needs to be sufficiently watered and monitored for pest invasions, without resorting to too many pesticides or herbicides. Additionally, make sure your soil’s pH levels are kept in the range of 5 to 8.5, with good drainage and gradation.

When maintaining your St. Augustine turfgrass over the spring and summer months, set your lawnmower to a higher setting to maintain plenty of length so the blades can photosynthesize efficiently and the plants can grow denser than ever.

Why Is My St. Augustine Grass Turning Yellow?

A lack of nutrients is often the cause for faded or yellowing St. Augustine grass. Because St. Augustine turfgrass requires many essential nutrients from the soil, if your yard is not able to add to your grass’s feeding, it will start to fade.

To regain a green glow for your grass, make sure to routinely apply the best fertilizer for St. Augustine grass. Slow-release fertilizers are a great option, as they guarantee feeding and nutrient seepage for your lawn between applications.

Any lawn feeding product for St. Augustine grass that is composed of a mixture of iron and nitrogen is essential for keeping everything green and lush. Additionally, spraying your lawn with plant sulfates at a dilution of 2 ounces to 3-5 gallons of water for every 1,000 square feet can be helpful to encourage a greener yard.

Sunshine And St. Augustine Grass

For access to naturally occurring nutrients, keep your St. Augustine grass in full sun. If you notice a lot of shady patches forming because of shrubs or tree coverage, this could be the root of your yellowing St. Augustine grass issue.

A sunny St. Augustine grass yard is a happy one—opt for fences that don’t block out the sunshine, and trim back the verge that might keep your grass in shadow. St. Augustine grass thrives when it has access to at least six to eight hours of direct sun.

Is Epsom Salt Good For St Augustine Grass?

Surprisingly, Epsom salts are not only good for the bath, but also for your St. Augustine grass. Applying Epsom salt to your yard will not only increase vital nutrients in the soil, but also act as a natural fertilizer and pesticide that won’t harm your yard or other plants.

Because St. Augustine grass benefits greatly from the application of iron, nitrogen, and other necessary sulfates, Epsom salt is the ideal choice for a natural applicant due to high levels of iron and minerals.

Furthermore, Epsom salt contains plenty of magnesium that will help to balance the soil’s pH level and encourage healthier root systems and better grass growth for your St. Augustine turf.

Simply add about half a pound of Epsom salt for every 100 square feet to your lawn spreader and apply it to the yard. Don’t worry if the Epsom salt scatters into your garden beds, either; it should act as a natural pesticide there and repel a variety of common bugs and slugs.

It is most effective as a spring or fall application to avoid weed growth during the height of summer.

What Month Should I Fertilize St Augustine Grass?

The exact month that is ideal for fertilizing your St. Augustine grass does depend on your location and the inherent weather systems of your area. But there are some basic guidelines to follow for when your St. Augustine grass is safe to be fertilized.

The first fertilization should take place about two or three weeks after the final frost, after the grass has turned green again. This is when St. Augustine grass breaks its wintertime dormancy period, and requires extra support to get summer-ready.

As this will be the first fertilization of the season, you want to ensure plenty of nutrients go into the soil to re-propagate the sod after the winter months. Apply a high-nitrogen fertilizer to all your St. Augustine turfgrass and water it completely, though not too much.

Instead of relying on just one or two watering sprees, stick to a regular irrigation schedule that allows your soil to become saturated and then fully absorb it afterward.

A proper watering schedule will help your soil  fully use the fertilizer nutrients, instead of leaving them to accumulate in ineffectual clumps.

Buyer’s Guide To Lawn Fertilizer

It’s no secret that the gardening market is full of fertilizer types and brands that all claim to be the best for your lawn. But which selection is truly the best fertilizer for St. Augustine grass?

To help narrow down your options, here are some questions to keep in mind when shopping.

Guide To Lawn Fertilizer

How Big Is Your Lawn?

Make sure the fertilizer you select will cover your yard adequately, and not just over one or two applications. Most fertilizers need to be reapplied every six weeks for the best results, so you don’t want to run out of product mid-season.

Most packages of fertilizer granules contain enough to treat at least 1,000 square feet of lawn space, but this might not be enough for your needs. Determining the size of your yard will help narrow down the size of the product required.

Large lawns are typically around 10,000 square feet, medium lawns around 5,000 square feet, and small lawns at about 2,50 square feet of space.

Fertilizer Makeup

While fertilizers all tend to contain the most basic necessities for lawn nutrients, such as nitrogen and iron, some may have even more helpful ingredients.

Further nutrients such as phosphorus and potassium are crucial for grass propagation. In addition, calcium, sulfur, carbon, and a host of sixteen other important nutrients also encourage healthy St. Augustine grass growth.

Quick Or Slow?

A majority of fertilizers market themselves as either fast or slow-release, or a combination of the two. But which type is better when it comes to the best fertilizer for St. Augustine grass?

Quick-release fertilizers allow nitrogen to immediately disperse into the soil, whereas slow formulas will draw it out in small doses. While quick-release types will get the grass growing greener faster, it is better to rely on extended and sustainable nutrition through slower or control-release fertilizer formulas.

Final Thoughts

For turf enthusiasts, St. Augustine grass is a great option for most yards. It is a robust, densely growing grass that can withstand a range of temperatures and soil types.

However, like some other turf types, St. Augustine grass still does require some human intervention in order to grow abundantly and healthily. Selecting the best fertilizer for St. Augustine grass is important, as is regular application scheduling and watering regimes.

If you treat your St. Augustine grass right, it will continue to grow verdant and lush for the entire season, and possibly leave your neighbors green themselves—with yard envy!

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