The Best Fertilizer for St. Augustine Grass

All living things need to feed—including St. Augustine grass. Finding the right fertilizer for it and performing proper maintenance will ensure a green, lush landscape all year long. When fertilized correctly, it will also produce a dense root system that withstands external stressors such as disease damage, insect invasions, weeds or even damage related to weather.
When it comes to selecting a fertilizer, one of the best things you can do is collect and submit a soil analysis so that you know exactly which nutrients are currently in your soil and which nutrients your grass needs. This will give you an overall better understanding of which fertilizer you need to select. Understanding N-P-K ratios and how to read a fertilizer label will also help you during the selection process.
Generally speaking, St. Augustine nutrient requirements may slightly alter depending on location, climate and soil conditions. However, we have listed some of the best St. Augustine grass fertilizers.
Best Fertilizer for New St. Augustine Lawns
- Perfect for newly planted sod, grass plugs or seed
- Establishes a root system
- Delivers carbon, amino acids and microbes for soil health
- Liquid fertilizer box with three bottles of fertilizer that covers 5,000 sq. ft.
- Features Catalyst Technology
Best Liquid Fertilizer for St. Augustine Lawns
- Feed lawns the nutrients they need all year long
- Contains the proper nutrient ratios as temperatures and soil conditions change
- Contains three fertilizer boxes each filled with three different bottles of fertilizer
- Can be purchased through the annual or monthly subscription; or as individual boxes
- Each bottles covers 5,000 sq. ft.
- Features Catalyst Technology
Best Granular Fertilizer for St. Augustine Lawns
- 25 lb. bag of granular fertilizer
- Can be used during any of the active growing seasons
- Features a slow-release mixture of nitrogen
- Each bag covers 5,000 sq. ft.
- Features Catalyst Technology
Lawnifi’s New Lawn Starter Box
Lawnifi’s New Lawn Starter Box contains three bottles of liquid fertilizer: Grow, a second bottle of Grow and Maintain. Each bottle of fertilizer should be applied at a specific time during St. Augustine’s establishment process. In other words, this fertilizer box is perfect for newly sodded St. Augustine lawns. It can also be used on newly planted St. Augustine grass plugs. The New Lawn Starter Box can be used on newly planted seed as well, but there’s no such thing as St. Augustine seed.
The first bottle of Grow should be applied the day of installation/planting. The second bottle of Grow can be applied two weeks later and the last bottle of Maintain should be applied after another two weeks, which is four weeks after the day of planting. Each bottle easily hooks up to the end of your garden hose for an even spray distribution and covers 5,000 sq. ft.
Grow has a NPK ratio (nitrogen-phosphorus-potassium) of 8-8-8. Grow is designed to promote healthy root growth on newly planted sod, grass plugs or seed. It also contains carbon, which is beneficial for the soil’s overall health. When you have healthy soil, you have a healthy environment for plants to grow in it. Maintain has a NPK ratio of 16-0-4 that is designed to enhance the color of your new lawn. It also contributes to healthy soil composition by delivering amino acids and microbes.
Once the first 30 days after installation or planting have gone by, begin transitioning your St. Augustine to a regular maintenance schedule with some of the seasonal boxes below. Temperatures and soil conditions change throughout the year as temperatures rise and drop significantly. With changing temperatures and soil conditions, your established St. Augustine’s needs will vary.
Lawnifi’s Spring Fertilizer Box
As one of the seasonal boxes from the annual or monthly subscription, the Lawnifi Spring Fertilizer Box can also be purchased separately as an individual box. The Spring Fertilizer Box contains three bottles of liquid fertilizer that should be applied at a specific time throughout the spring season.
With a 16-0-4 NPK formulation, Maintain should be applied at the beginning of spring to promote healthy roots and the return of green leaf blades in your St. Augustine after winter dormancy. It can also be applied to St. Augustine that doesn’t go dormant during the winter.
The second bottle in the box, Boost, further deepens the green appearance of your St. Augustine with a 30-0-0 NPK ratio and a time-release formula. Boost should be applied four weeks after the first application of Maintain.
The last bottle of the Spring Fertilizer Box, a second bottle of Maintain, should be applied another four weeks after the application of Boost. This last application of Maintain gives your St. Augustine nutrients that prepare it for the stressful summer heat.
Lawnifi’s Summer Fertilizer Box
The Lawnifi Summer Fertilizer Box is also apart of the annual or monthly subscription. However, it can also be purchased separately as its own individual box. Designed to help your lawn beat the summer heat, the Summer Fertilizer Box contains three bottles of liquid fertilizer that should be applied at specific times throughout the summer.
Once again, the first bottle of the Summer Fertilizer Box is Maintain, which should be applied anytime during the first few weeks of the summer. This will help your St. Augustine continue to prepare for the rising temperatures.
In the mid-summer—four weeks after applying Maintain—apply Recover to help your St. Augustine get through the dog day stress of summer. You will also make a second application of Lawnifi Recover with the last bottle four weeks after your first application of Recover. Recover’s 13-0-0 formulation also contains important micronutrients like manganese, iron and sulfur.
Lawnifi’s Fall Fertilizer Box
The last fertilizer box in the annual or monthly subscription program is the Fall Fertilizer Box. The Fall Fertilizer Box can be purchased separately as its own individual box and contains one bottle of Boost, one bottle of Maintain and one bottle of Recover. Each of the three different bottles should be applied at specific times during the fall. The Fall Fertilizer Box is designed primarily to revitalize your St. Augustine after the summer heat and prepare it for winter temperatures.
Start with applying Boost in the first few weeks of the fall season to revitalize the green leaf blades after the stressful heat of the summer. The rapid green-up of your St. Augustine will last from the time of application through the remainder of the growing season as a result of Boost’s time-release formulation. In mid-fall, apply Maintain for well-balanced nutrition and in late fall, apply Recover to prepare your lawn for winter dormancy.
Lawnifi Foundation
In comparison to the three liquid fertilizer boxes above, Lawnifi Foundation is a granular fertilizer that can be used throughout any of the active growing seasons.
With a 29-0-5 formulation, Lawnifi Foundation features a slow-release mixture of nitrogen that feeds your plants over a longer duration of time. Lawnifi Foundation’s application rate should be set on your spreader to apply 5 lbs. of fertilizer per 1,000 sq. ft. After applications have been made, be sure to water the product in to help with absorption. To learn more about Lawnifi Foundation, click here.
Catalyst Technology
All Lawnifi products are powered by Catalyst TechnologyTM, which nano-sizes fertilizer nutrients to make the delivery process and breakdown of nutrients more efficient. In place of working to break nutrients down, Lawnifi fertilizer is readily available for the plant to absorb through its roots and leaves at the time of application. Lawnifi’s granular and liquid fertilizer programs both use Catalyst Technology to help nutrients reach plants’ systems at a faster rate. Less product is used and more fertilizer is absorbed. Learn more about Lawnifi in Why Use Lawnifi Fertilizer?.
Lastly, if you aren’t sure of the differences between granular and liquid fertilizer, check out our Sod University article that explains the differences here.