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10 Best Fertilizers for St. Augustine Grass

Discover the best fertilizers for St. Augustinegrass in 2024, tailored for different seasonal needs and growth stages, ensuring lush, vibrant lawns.

How lovely it seems to picture yourself stepping outside on a sunny morning, and admiring your lush, green lawn full of St. Augustine grass. Having this grass in your garden is a pride for all lawn-enthusiasts. But this grass needs a little extra care to maintain it at its best. 

That’s where fertilizers do their magic.

We’ve done the digging and rounded up the top 10 fertilizers for St. Augustine grass in 2024. From organic blends to professional-grade formulas, this list covers all the kinds of fertilizers you should know about. 

Best Fertilizers for Different Needs of St. Augustine Grass 

Green grass in a field thriving with the help of the best fertilizers for different needs of St Augustinegrass

Choosing the right fertilizer for your St. Augustine grass is not as easy as it seems. Because selecting a fertilizer out of these flooded options feels like searching for a needle in a haystack. But we are here to save you time and effort.

Read ahead to learn what fertilizer will suit St. Augustine grass in different situations. 

Fertilizer for Post-Winter Application

As spring announces its arrival, your St. Augustine grass also wakes up from its winter sleep. This is a prime time to give a nutritional boost to your grass to ensure growth and health. These two fertilizers will work perfectly at this stage.

1. Expert Gardener Texas Turf Lawn Food (18-5-9)

You can think of it as a power breakfast for your lawn. This fertilizer is loaded with nitrogen (the “N” in 18-5-9). It activates the grass and gives it a kickstart for growth. Extra iron for a deep, healthy green color is a bonus nutrient. 

But remember, too much nitrogen could give your grass a sugar rush. Consequently, it might grow too fast and become susceptible to disease. Make sure you keep a light hand while applying.

2. Down to Earth Organic Bio-Turf (8-3-5)

The best part about this fertilizer is that you can use it without harming the environment. The reason is the organic nature of this fertilizer. It releases slowly into the soil, giving it the necessary dose of nitrogen in a nourishing manner. 

This way, it not only awakens your grass but also mends a way for its long-term health. It is indeed an investment in your lawn’s long-lasting foundation. The only drawback of organic options is their slow process. 

Fertilizers for Balancing the Heat

The summer heat does not only hit humans; it affects the lawn’s grass equally. Moreover, just like how you need sunscreen to protect your skin, St. Augustine grass will need a shield to save its shine. 

The following fertilizers are a good fit for summer. 

3. Espoma Organic All-Season Lawn Food (5-2-5)

A bird standing in sunny grass Fertilizers for Balancing the Heat

This fertilizer acts as a summer shield for your lawn. It’s packed with beneficial microbes that contribute to a healthy root development, crucial for fighting heat and potential drought conditions.

However, be aware of the lower nitrogen content of this fertilizer. This fertilizer will surely help your grass to survive the summer. Nevertheless, you have to note that applying low-nitrogen fertilizer may affect the color and appearance of the grass. 

4. Lesco 15-0-15

Sometimes, St. Augustine grass needs a good amount of potassium (the “K” in 15-0-15) during the high heat of summer months. This fertilizer focuses particularly on potassium, as it is a vital nutrient that helps your lawn fight off disease and pests, keeping it strong throughout the hot season.

The downside of Lesco is that the hard dose of potassium can disrupt the balance of other nutrients in the soil. Henceforth, be sure to follow the application instructions carefully.

Fertilizers to Apply in Fall

As summer fades and fall marks its presence, it’s time to help your St. Augustinegrass prepare for the weather the coming winter. 

You should opt for these fertilizers if you want to save your St. Augustine grass from the cold winters.

5. Jonathan Green Winter Survival Fall Fertilizer (10-0-10)

This fertilizer acts like a winter coat for your lawn. With its special mix of slow-release nitrogen and potassium, this fertilizer acts like a shield, protecting your grass during the winter months. It’s like giving your lawn an extra layer of strength to stay green and healthy when spring arrives.

But here’s the thing: if you live in a place where winters aren’t too harsh, this fertilizer might be a bit too much. 

6.. BioAdvanced 3-in-1 for Southern Lawns (18-5-9)

BioAdvanced 3-in-1 for Southern Lawns is one of the most impactful fertilizers to apply in the fall. It also controls unwanted weed growth which makes it a must-have for lawn care. It has a balanced composition that stimulates a healthy root system. It prepares your lawn for winter while giving a head start on spring growth. 

With just one application, it looks after fall lawn care, ensuring a lively and resilient lawn throughout the season. It’s an all-in-one solution for busy lawn owners.

The only flaw is that if you don’t apply such combinations properly, they can be harsh on your lawn.

Fertilizers for Strong Roots and Healthy Grass 

Who does not want their grass to stay strong and healthy throughout the year? Only a strong root system can foster healthy grass. These fertilizers will fit your intention of providing proper nutrition to your St. Augustinegrass. 

7. NPK 16-20-0 Fertilizer

bag npk 16 20 0 1

The NPK 16-20-0 Fertilizer can be your lawn’s new best friend. This fertilizer comes with a heavy dose of phosphorus. This fertilizer is a savior for your St. Augustine roots, as phosphorus is responsible for root growth.

With NPK 16-20-0 Fertilizer, you’re not just feeding your lawn—you’re giving it the building blocks it needs to flourish.

8. NPK 18-18-18 Fertilizer

bag, npk 18-18-18, 1

NPK 18-18-18 Fertilizer comes with a sense of balance as it possesses macronutrients your St. Augustinegrass needs. It’s like serving up a nutritious feast for your lawn, along with all the required elements. 

This fertilizer comes with equal parts of nitrogen, phosphorus, and potassium. 

NPK 18-18-18 Fertilizer provides everything your grass needs to stay healthy and vibrant. Nitrogen fuels lush green growth, phosphorus strengthens the roots, and potassium enhances overall resilience ability. 

Organic Fertilizers 

If you are implementing an eco-friendly approach to your gardening, here are the organic fertilizers for your lawn needs.

9. Milorganite 6-4-0 (Slow-Release Nitrogen Fertilizer)

This one is a unique option because it is made from recycled materials. Milorganite provides slow-release nitrogen to your grass while encouraging steady green growth without the risk of burning your grass.

So, if you’re all about going green and want a fertilizer that’s easy on your lawn and the environment, Milorganite 6-4-0 is the way to go. 

10. The Andersons Innova 7-1-2 Organic Lawn Fertilizer

The Andersons Innova 7-1-2 Organic Lawn Fertilizer stands out for its environment-friendly composition. It gives overall nutrition to your St. Augustine grass without any harsh chemicals. 

This organic mix is gentle on your grass while delivering the nutrients. You can rely on Andersons Innova for a naturally lush and vibrant lawn, free from synthetic additives.

Tips for St. Augustine Grass Care

A person carefully trims grass with scissors following tips for St Augustine grass care

Fertilizers are a great help for a strong root system and flourishing grass. But fertilizers also show results when you take care of your St. Augustine grass lawn. Here are some care tips:  

  • Mow Smartly: Whether you hire a mower or you mow your St. Augustine grass on your own, keep it at a height of 3-4 inches. This allows sunlight to reach the base, which encourages healthy growth.
  • Water Wisely: Don’t water your St. Augustine grass too much or too little. The ideal way to water your lawn is a soaking rain-like session. It means that water reaches the entire roots, while the top inch of the grass remains dry. This technique is called deep watering. It helps roots to grow deep in the soil, making your lawn more resilient. 
  • Aeration: Aeration is poking small holes in the soil, allowing air and water to circulate better. This is like giving your St. Augustine grass a healthy dose of oxygen, helping the roots breathe and grow strong, especially in areas with compacted soil. 
  • Foster Biodiversity: Consider adding some native, low-maintenance plants like wildflowers or ornamental grasses to make your plants a diverse habitat for pollinators like bees and butterflies. It also  adds beauty and attracts useful creatures to your yard. Additionally, these plants can even help to suppress weeds naturally.

Bottom Line

You can now say goodbye to getting confused to choose the best fertilizer for your  St. Augustine grass. You have now got the knowledge to create a green oasis that’s good for you and the Earth. Contact us to know which fertilizer suits your St. Augustine grass.

Remember, a healthy lawn is not just a pretty view – it cleans the air, cools things down, and provides a home for helpful bugs. Furthermore, everything needs care and attention. So try to be aware of what your lawn needs and enjoy your green paradise. 


1. What’s the right time to fertilize St. Augustine Grass?

You should fertilize your St. Augustine grass every 6-8 weeks in the growing period and before summer and winter after full growth. 

2. Should I use granular or liquid fertilizer for St. Augustine Grass?

Both the options work great when applied to St. Augustine grass. Nonetheless, granular fertilizer is preferable as it has a lasting effect in less application.

3.  How do you know if St. Augustinegrass needs fertilization? 

Keep an eye on the signs of nutrient deficiency, like yellowing or slow growth. And don’t forget to do a soil test twice a year. Afterward, decide which fertilizer your soil needs for better growth of St. Augustine grass. 

4. How to create an eco-friendly lawn with St. Augustinegrass?

Prefer using organic fertilizers, mow your lawn at the recommended height (3-3.5 inches for St. Augustine grass), and water deeply promotes healthy roots. Try to grow some other plants to attract friendly insects and bugs. 

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