Many homeowners treat their lawn like a generic patch of dirt, applying whatever big-box store bag happens to be on sale. St. Augustine grass is actually quite picky, and feeding it the wrong nutrients can leave your turf yellow or susceptible to disease.
Identifying the Best St Augustine Grass Fertilizers requires looking at specific nitrogen and iron ratios. Focusing on the right chemical balance will save you months of regret later.
Key Takeaways
- Prioritize formulas with high nitrogen content to encourage the thick runners that define healthy St. Augustine grass.
- Choose phosphorus free options unless a soil test confirms your ground is critically deficient in that mineral.
- Look for slow release nitrogen sources to feed the roots gradually over several weeks instead of causing a quick, unsustainable growth spurt.
- Check the iron percentage to ensure your grass maintains a deep green color without forced, unhealthy leaf elongation.
- Match your application method to your equipment, as liquid sprays provide faster coverage while granules offer long term soil amendment.
| Best Overall Weed Control |  |
LESCO St. Augustine Weed and Feed | Combines feeding and weeding | Strong herbicide performance | Designed for St. Augustine | View on Amazon | Read Review |
| Rapid Nutrient Delivery |  |
Liquid St. Augustine Lawn Food | Fast acting results | Encourages lateral spreading | Easy spray application | View on Amazon | Read Review |
| Long Lasting Nutrition |  |
Sunniland St. Augustine Slow Release Fertilizer | Slow release nitrogen | Phosphorus free formula | Good for large areas | View on Amazon | Read Review |
| Iron Rich Color Boost |  |
Fertilome Centipede and St. Augustine Fertilizer | High iron for color | Balanced nutrient ratio | Slow release nitrogen | View on Amazon | Read Review |
| Quick Greening Specialist |  |
Scotts Green Max Lawn Food | Rapid greening effect | Added iron supplement | Easy to spread | View on Amazon | Read Review |
| Versatile Liquid Feed |  |
Simple Lawn Solutions Balanced Fertilizer | Balanced NPK ratio | Easy spray application | Works on many grasses | View on Amazon | Read Review |
| Reliable General Maintenance |  |
Scotts Turf Builder Lawn Food | Reliable nutrient blend | Works on any grass | Simple to apply | View on Amazon | Read Review |
| Broadleaf Weed Fighter |  |
Scotts Weed and Feed | Kills common weeds | Feeds the lawn | Easy to spread | View on Amazon | Read Review |
| Heavy Duty Growth |  |
SeedRanch St. Augustine High Nitrogen Fertilizer | High nitrogen count | Large bag size | Promotes rapid growth | View on Amazon | Read Review |
| Nutrient Dense Cocktail |  |
Superior Liquid Lawn Fertilizer | Includes organic additives | Easy sprayer attachment | Balanced nutrient blend | View on Amazon | Read Review |
More Details on Our Top Picks
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LESCO St. Augustine Weed and Feed
If you struggle with weeds taking over your turf, this is your primary defensive tool. It combines a potent fertilizer with Penoxsulam, which targets invasive broadleaf weeds while simultaneously providing the nutrients your St. Augustine needs to fill in those bare spots.
You should use this when weeds are actively growing to get the best results. Keep in mind that because it contains a herbicide, you must be careful to avoid applying it near trees or ornamental flower beds where the chemicals could migrate.
- Brand:LESCO
- Fertilizer Type:Granular
- Package Weight:50 lbs
- Primary Ingredient:Penoxsulam
- Additional Feature:Kills broadleaf weeds effectively
- Additional Feature:Promotes dense grass growth
- Additional Feature:Professional grade formulation
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Liquid St. Augustine Lawn Food
When your grass looks a bit tired and lacks that vibrant green pigment, liquid applications are the quickest way to wake it up. This liquid formula is designed to get into the soil and reach the roots immediately.
It excels at encouraging new runners to spread across your yard. Because it is a liquid, you will need to reapply it more frequently than granular options to keep those growth levels consistent.
- Brand:Unbranded
- Fertilizer Type:Liquid
- Package Weight:1 Gallon
- Additional Feature:Promotes rich green color
- Additional Feature:Supports thick grass growth
- Additional Feature:Simple application process
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Sunniland St. Augustine Slow Release Fertilizer
Consistent feeding is the secret to a healthy lawn, and this slow release nitrogen formula ensures your grass doesn't just surge and then crash. It provides a steady stream of nutrients over time, which reduces the need for constant reapplications.
Since this is phosphorus free, it is a smarter choice for regions with strict environmental runoff regulations. You get plenty of coverage in a single bag, making it a reliable workhorse for larger yards.
- Brand:Sunniland
- Fertilizer Type:Granular
- Formula Ratio:20-0-6
- Application Coverage:5,000 sq ft
- Package Weight:20 lbs per bag
- Additional Feature:Steady nutrient delivery
- Additional Feature:Environmentally conscious blend
- Additional Feature:Professional quality ingredients
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Fertilome Centipede and St. Augustine Fertilizer
Sometimes your grass is healthy but lacks that deep, dark green color you see in magazines. This formula uses high iron content to correct that issue without pushing excessive, weak top growth that might otherwise be caused by too much nitrogen.
The balanced 15-0-15 ratio provides a stable diet for warm season grasses. It is a solid choice if you want to focus on color and structural integrity rather than just rapid blade elongation.
- Brand:Fertilome
- Fertilizer Type:Granular
- Formula Ratio:15-0-15
- Package Weight:16 lbs
- Additional Feature:Enhances turf density
- Additional Feature:Safe for warm season grasses
- Additional Feature:Prevents nutrient spikes
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Scotts Green Max Lawn Food
If you want to see a visible change in your lawn's color within a few days, this is the product you want in your shed. It features a dual action approach that feeds the grass while providing a significant boost of iron for immediate visual impact.
It is particularly useful for a mid season pick me up when your lawn looks a little dull. Be aware that this is a fast acting product, so do not expect it to provide the same long term feeding duration as a slow release alternative.
- Brand:Scotts
- Fertilizer Type:Granular
- Application Coverage:5,000 sq ft
- Package Weight:16.67 lbs
- Additional Feature:Visible results quickly
- Additional Feature:Trusted industry brand
- Additional Feature:Consistent particle size
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Simple Lawn Solutions Balanced Fertilizer
Having a balanced 16-4-8 ratio means this fertilizer is versatile enough to help almost any type of grass thrive. The liquid delivery is perfect for homeowners who prefer a sprayer over a heavy broadcast spreader.
It works exceptionally well during the spring and summer months when your lawn is hitting its peak growing phase. Because it is a concentrate, you can manage exactly how much product you use across different sections of your property.
- Brand:Simple Lawn Solutions
- Fertilizer Type:Liquid
- Formula Ratio:16-4-8
- Package Weight:32 Ounce
- Additional Feature:Concentrated liquid formula
- Additional Feature:Works for all seasons
- Additional Feature:Simple to store
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Scotts Turf Builder Lawn Food
This is the classic, reliable choice for anyone who wants a straightforward feeding schedule without any extra bells or whistles. It provides the foundational nutrients that St. Augustine needs to stay healthy and resilient against foot traffic and heat.
It is designed to work with all grass types, which is helpful if you have a mixed lawn. Just remember that this product focuses on general health, so you will need a separate treatment if you are fighting active weed infestations.
- Brand:Scotts
- Fertilizer Type:Granular
- Application Coverage:5,000 sq ft
- Package Weight:12.5 lbs
- Additional Feature:Improves overall grass density
- Additional Feature:Consistent granular size
- Additional Feature:Established brand performance
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Scotts Weed and Feed
When your lawn is being invaded by dandelions and clover, you need a targeted solution that kills the weeds while nourishing the grass. This product solves both problems in one pass, which saves you a significant amount of time on the weekend.
It is an efficient way to clean up your turf before the heat of summer sets in. Always check your local weather, as you want to apply this when the grass is damp but no rain is expected for a day or two.
- Brand:Scotts
- Fertilizer Type:Granular
- Application Coverage:5,000 sq ft
- Package Weight:14.29 lbs
- Additional Feature:Controls clover effectively
- Additional Feature:Boosts grass growth
- Additional Feature:Convenient dual action
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SeedRanch St. Augustine High Nitrogen Fertilizer
If you have a large, hungry lawn that needs a substantial nitrogen boost, this 50 pound bag is the right scale for the job. The 24-2-11 ratio provides a strong kick of nitrogen to drive aggressive growth and leaf production.
This is best for established, mature lawns that need a serious nutritional replenishment. Due to the high nitrogen content, ensure you water it in thoroughly after application to prevent any risk of burning the grass blades.
- Brand:SeedRanch
- Fertilizer Type:Granular
- Formula Ratio:24-2-11
- Package Weight:50 lbs
- Additional Feature:Targeted for St. Augustine
- Additional Feature:Sustained feeding capability
- Additional Feature:Professional level quantity
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Superior Liquid Lawn Fertilizer
This is more than just standard fertilizer because it includes humic acid, fish, and seaweed. These ingredients work together to improve your soil health, which makes it easier for your grass to absorb the nitrogen and potassium provided in the mix.
The included sprayer attachment makes the application process feel nearly effortless. It is a fantastic option for those who want to provide their lawn with a more holistic, nutrient dense diet rather than just a basic chemical feed.
- Brand:Simple Lawn Solutions
- Fertilizer Type:Liquid
- Formula Ratio:15-0-15
- Package Weight:32 Ounce
- Additional Feature:Contains humic acid
- Additional Feature:Includes fish and seaweed
- Additional Feature:All season application
Frequently Asked Questions
How often should I fertilize my St. Augustine lawn?
You should aim to fertilize about four to six times per year during the active growing season. Start your first application in the spring once the grass has fully greened up and stop at least six weeks before the first expected frost in the fall.
Can I use a standard lawn fertilizer on St. Augustine?
Not always, because many general-purpose fertilizers contain herbicides that are toxic to St. Augustine. Always look for a label that explicitly mentions St. Augustine compatibility, especially if the product includes weed control.
Is it better to use liquid or granular fertilizer?
Granular fertilizer is usually the better choice for the home lawn because it is easier to apply evenly and offers longer-lasting results. Liquid fertilizers work faster if your grass is severely nutrient-deficient, but they require much more frequent applications to maintain the same effect.
What should I do if I accidentally apply too much fertilizer?
If you notice the grass turning brown or yellow in streaks, you have likely suffered from fertilizer burn. Immediately water the area thoroughly to help flush the excess salts through the soil profile and away from the roots.
Do I need to water after applying fertilizer?
Yes, you should lightly irrigate your lawn with about a quarter-inch of water after applying granular products. This washes the fertilizer off the blades and into the soil where the roots can actually absorb the nutrients.
