7 Best St Augustine Fertilizers in 2026

September 8, 2026
Written By Thomas James

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St. Augustine grass demands specific nutrients to survive the heat, and picking the wrong ratio is like feeding a toddler coffee instead of milk. You want a balanced green without forcing the grass to outpace its own root system.

Choosing the Best St Augustine Fertilizers starts with understanding the nitrogen needs of your soil. Let's walk through these specific options to keep your lawn thick and healthy this season.

Key Takeaways

  • Prioritize formulas that specify St. Augustine compatibility to avoid chemical burns on delicate blades.
  • Select between liquid concentrates for rapid absorption or granular options for slow-release feeding throughout the month.
  • Check the NPK ratio closely because too much nitrogen can invite unwanted fungal diseases in humid climates.
  • Consider if you need a combined weed killer to save time, but remember that granular combo bags work best when applied to moist leaves.
  • Match your container size to your total square footage to ensure you have enough coverage for at least two complete feeding cycles.

Our Top Best St Augustine Fertilizers Picks

Best Overall Liquid Liquid St Augustine Lawn Food Liquid St Augustine Lawn Food Rapid nutrient absorption Designed for St Augustine Thickens turf density View on Amazon Read Review
Ideal Spot Treatment Liquid St Augustine 32oz Food Liquid St Augustine 32oz Food Perfect for small areas Same effective formula Easy to manage container View on Amazon Read Review
Best For Small Pots Liquid St Augustine 8oz Sample Liquid St Augustine 8oz Sample Highly concentrated formula No wasted product Easy to store View on Amazon Read Review
Potent Weed Control Fertilome St Augustine Weed Feed Fertilome St Augustine Weed Feed Dual weed and feed Steady nutrient release Robust nitrogen content View on Amazon Read Review
Best Balanced Formula Simple Lawn Solutions Balanced Fertilizer Simple Lawn Solutions Balanced Fertilizer Balanced nutrient profile Versatile across grass types Quick greening effect View on Amazon Read Review
Best Insect Defense BioAdvanced 3-in-1 Liquid Spray BioAdvanced 3-in-1 Liquid Spray Fertilizes and protects Kills common pests Controls broadleaf weeds View on Amazon Read Review
Heavy Duty Granular BioAdvanced 3-in-1 Weed Granules BioAdvanced 3-in-1 Weed Granules Convenient granular form Comprehensive pest control Reliable weed suppression View on Amazon Read Review

More Details on Our Top Picks

  1. Liquid St Augustine Lawn Food

    Liquid St Augustine Lawn Food

    Best Overall Liquid

    Rating unavailable
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    This gallon-sized jug is a reliable choice for homeowners who want to maintain a lush, thick lawn without dealing with heavy granular bags. It is formulated specifically for the unique nutritional needs of St. Augustine grass.

    Because it is a liquid formula, the nutrients reach the soil and root zone almost immediately. You should keep in mind that the large container requires a sprayer attachment, so ensure you have the right equipment on hand before you start.

    • Formula Type:Liquid
    • Application Method:Hose-end spray
    • Container Volume:1 Gallon
    • Additional Feature:Promotes rapid greening
    • Additional Feature:Easy to store bottle
    • Additional Feature:Encourages deep root growth
  2. Liquid St Augustine 32oz Food

    Liquid St Augustine 32oz Food

    Ideal Spot Treatment

    Rating unavailable
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    If you only have a smaller yard or need to touch up a few thinning patches, this 32-ounce size is the perfect match. It offers the same effective formula as the gallon version but in a much more manageable volume.

    This is a great tool for those who prefer precise application rather than blanketing an entire acre. Just remember that smaller bottles run out quickly if you are planning to cover a large, sprawling lawn.

    • Formula Type:Liquid
    • Application Method:Hose-end spray
    • Container Volume:32 ounces
    • Additional Feature:Targeted lawn repair
    • Additional Feature:Faster green up
    • Additional Feature:Simple application process
  3. Liquid St Augustine 8oz Sample

    Liquid St Augustine 8oz Sample

    Best For Small Pots

    Rating unavailable
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    Sometimes you just need a tiny amount to keep a small patch of grass healthy. This 8-ounce bottle is an unconventional but clever choice for those with very limited square footage or for a quick, mid-season boost on a trouble spot.

    It is highly concentrated, so a little goes a long way. Do not expect this to cover a full-sized backyard, as it is strictly meant for surgical, localized feeding.

    • Formula Type:Liquid
    • Application Method:Diluted spray
    • Container Volume:8 ounces
    • Additional Feature:Great for touch-ups
    • Additional Feature:Minimal storage space
    • Additional Feature:Quick acting nutrients
  4. Fertilome St Augustine Weed Feed

    Fertilome St Augustine Weed Feed

    Potent Weed Control

    Rating unavailable
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    When weeds start to crowd out your grass, you need a granular solution that attacks the problem at the source. This 15-0-4 blend provides the nitrogen your lawn craves while simultaneously knocking back common southern weeds.

    The granular format is excellent for long-term feeding, as the nutrients release steadily over time. Be aware that you must water the lawn thoroughly after spreading to activate the herbicide and prevent leaf burn.

    • Brand Name:Fertilome
    • Formula Type:Granular
    • Product Weight:25.6 lbs
    • Nutrient Ratio:15-0-4
    • Additional Feature:Targets broadleaf weeds
    • Additional Feature:Supports root health
    • Additional Feature:Easy to spread
  5. Simple Lawn Solutions Balanced Fertilizer

    Simple Lawn Solutions Balanced Fertilizer

    Best Balanced Formula

    Rating unavailable
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    Not every lawn requires a massive nitrogen hit, and that is where this 16-4-8 balanced liquid shines. It provides a more nuanced approach to feeding, ensuring your soil gets a well-rounded diet during the heat of summer.

    This is a versatile pick that works on any grass type, making it a smart choice if you have a mixed lawn. Just keep in mind that you will need to spray it more often than granular options to maintain that steady growth cycle.

    • Brand Name:Simple Lawn Solutions
    • Formula Type:Liquid
    • Application Method:Hose-end spray
    • Container Volume:32 ounces
    • Nutrient Ratio:16-4-8
    • Additional Feature:Spring and summer use
    • Additional Feature:Concentrated liquid formula
    • Additional Feature:Fast acting results
  6. BioAdvanced 3-in-1 Liquid Spray

    BioAdvanced 3-in-1 Liquid Spray

    Best Insect Defense

    Rating unavailable
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    Dealing with pests is often just as important as feeding the grass. This 3-in-1 formula acts as a fertilizer, a weed killer, and an insect repellent all in one go, saving you from having to mix multiple products.

    It is a massive time-saver for anyone who wants a healthy, pest-free lawn with minimal effort. Because it covers so many bases, you should be careful to follow the label directions exactly to avoid over-applying the insecticide component.

    • Brand Name:BioAdvanced
    • Formula Type:Liquid
    • Application Method:Hose-end spray
    • Product Weight:10 lbs
    • Additional Feature:Southern lawn specific
    • Additional Feature:Multi-action protection
    • Additional Feature:Simplifies lawn chores
  7. BioAdvanced 3-in-1 Weed Granules

    BioAdvanced 3-in-1 Weed Granules

    Heavy Duty Granular

    Rating unavailable
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    If you prefer the set-it-and-forget-it nature of granules, this is the version of the 3-in-1 formula for you. It stays on the soil surface longer than liquid, which can be beneficial for persistent weed suppression.

    This bag is an efficient way to feed your lawn while treating for bugs and weeds in one pass with a broadcast spreader. Just ensure your lawn is slightly damp before applying so the granules can stick to the weeds properly.

    • Brand Name:BioAdvanced
    • Formula Type:Granular
    • Application Method:Broadcast spreader
    • Product Weight:10 lbs
    • Additional Feature:Southern lawn formula
    • Additional Feature:Long lasting feeding
    • Additional Feature:Effective weed control

Factors to Consider When Choosing Best St Augustine Fertilizers

Nitrogen To Iron Ratio

St. Augustine grass is a hungry plant that thrives on high nitrogen levels to maintain its deep green color and rapid growth. Look for a fertilizer with a higher first number in the NPK ratio, such as 24-0-0 or 20-0-5. Adding iron helps the grass achieve that dark, emerald hue without forcing excessive growth that might weaken the root system.

Slow Release Formula

Your lawn is like a person who prefers a steady, balanced diet over a massive, sugar-loaded feast. Slow-release fertilizers provide nutrients gradually over 8 to 12 weeks, which prevents the grass from burning. This approach encourages a consistent growth pattern rather than a sudden, unmanageable surge that requires constant mowing.

Weed Control Integration

Many fertilizers include pre-emergent or post-emergent herbicides to kill weeds while feeding the grass. You must be careful here, because applying a weed-and-feed product when the temperature is above 85 degrees Fahrenheit can seriously damage your lawn. Always verify that the herbicide is specifically labeled for St. Augustine, as this grass is sensitive to certain chemicals that other varieties handle fine.

Soil pH Compatibility

St. Augustine grass prefers slightly acidic soil with a pH between 6.0 and 7.5. If your soil is too alkaline, the grass cannot absorb nutrients properly, which leads to yellowing blades. Use a soil test kit before buying fertilizer to see if you need a product that includes sulfur to help lower the pH.

Application Timing

Feeding your lawn is a seasonal commitment that starts when the grass breaks dormancy in the spring. You should aim for your first application after the final frost and continue through early fall. Avoid fertilizing in late fall or winter, as the grass needs to enter its natural dormant state to survive the cold.

Frequently Asked Questions

How often should I fertilize my St. Augustine grass?

You should feed your lawn every 6 to 8 weeks during the active growing season. This schedule provides enough fuel for the grass to stay dense and healthy without over-saturating the soil.

Will fertilizer kill my St. Augustine grass if I use the wrong kind?

Yes, it can, especially if the product contains chemicals like 2,4-D that are toxic to St. Augustine. Always check the label to ensure the product is explicitly cleared for your specific grass variety.

Do I really need to water after applying fertilizer?

You absolutely should water your lawn with about one-quarter inch of water shortly after application. This helps the granules move down into the soil where the roots can actually reach them.

Can I apply fertilizer during a drought?

It is best to wait for a rainy period or ensure you have a reliable irrigation system running before you apply fertilizer. If the ground is bone-dry and stressed, fertilizer can cause the grass to dry out further or sustain chemical burn.

Is a liquid or granular fertilizer better for my lawn?

Granular fertilizer is usually the best choice for long-term health because it breaks down slowly and lasts longer. Liquid fertilizers offer a quick color boost, but they wash away much faster and require more frequent applications.

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