Saint Augustine grass demands specific nutrition to stay lush. The most important difference between a quality fertilizer and a dud is the nitrogen-to-potassium ratio tailored for thick turf.
Selecting the Best Fertilizers for Saint Augustine Grass requires attention to your soil health. Getting this right prevents yellowing and helps your lawn resist summer heat. Keep reading for a breakdown of effective options for your yard.
Key Takeaways
- Prioritize high-nitrogen formulas if your primary goal is rapid greening and blade density.
- Check the phosphorus content because many Saint Augustine soils do not need the extra boost and can suffer from over-application.
- Opt for slow-release granular options if you prefer fewer applications throughout the active growing season.
- Use liquid fertilizers when you need immediate nutrient uptake during a dry spell or recovery phase.
- Verify whether the bag includes pre-emergent or post-emergent herbicides to handle weed control in one step.
| Best Overall Maintenance |  |
Sunniland St. Augustine Weed and Feed | Dual purpose formula | Effective weed control | Promotes dense growth | View on Amazon | Read Review |
| Top Liquid Feed |  |
Simple Lawn Solutions 16-4-8 Liquid Fertilizer | Rapid nutrient uptake | Balanced nutrient ratio | Easy hose application | View on Amazon | Read Review |
| Best Growth Booster |  |
St. Augustine Liquid Lawn Food | Promotes new runners | Rich green color | Easy mix application | View on Amazon | Read Review |
| Eco Conscious Choice |  |
Sunniland Phosphorus Free Lawn Fertilizer | Phosphorus free | Slow release nitrogen | Large coverage area | View on Amazon | Read Review |
| Heavy Duty Nutrition |  |
SeedRanch St. Augustine 24-2-11 Fertilizer | High nutrient concentration | Bulk bag size | Long lasting impact | View on Amazon | Read Review |
| Most Versatile Option |  |
Scotts Turf Builder Lawn Food | Trusted brand performance | Works on all grasses | Consistent quality | View on Amazon | Read Review |
| Best Spot Repair |  |
Scotts EZ Patch Repair Mix | Combines mulch and fertilizer | Fixes bare spots | Protects new growth | View on Amazon | Read Review |
| Summer Pest Defense |  |
Scotts SummerGuard Lawn Food | Fertilizer and insect control | Protects against summer stress | Easy to apply | View on Amazon | Read Review |
| Best Soil Conditioner |  |
Superior 15-0-15 Liquid Fertilizer | Includes humic and seaweed | Enhances soil health | Easy sprayer attachment | View on Amazon | Read Review |
| Commercial Grade Strength |  |
LESCO Weed and Feed | Pro-grade weed control | Effective on tough weeds | Reliable LESCO brand | View on Amazon | Read Review |
More Details on Our Top Picks
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Sunniland St. Augustine Weed and Feed
If you want to handle your weeds while feeding your lawn, this is your go-to option. It is specifically formulated to target common weeds while providing the nutrients your St. Augustine grass needs to stay thick and healthy.
Think of this as a two-for-one solution that saves you time on chore day. Just keep in mind that you should avoid using this on other delicate garden plants, as the weed-killing ingredients are quite potent.
- Brand Name:Sunniland
- Formula Type:Granular
- Coverage Area:5,000 sq ft
- Specific Purpose:Weed and feed
- Additional Feature:Kills broadleaf weeds
- Additional Feature:Supports lush green color
- Additional Feature:Easy to apply
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Simple Lawn Solutions 16-4-8 Liquid Fertilizer
This liquid spray is perfect for folks who prefer quick nutrient absorption over waiting for granules to break down. Because it is a balanced 16-4-8 formula, it acts like a morning espresso for your grass, providing a rapid boost when your lawn looks a bit sluggish.
It is incredibly versatile, so you can use it on any grass type, though it really shines when you need fast greening during the peak summer months. One small drawback is that you will need a hose-end sprayer, which requires a bit more active participation than spreading dry pellets.
- Brand Name:Simple Lawn Solutions
- Formula Type:Liquid
- Bag Weight:32 Ounce
- Key Ingredient:Nitrogen, Phosphorus, Potassium
- Specific Purpose:Seasonal feeding
- Additional Feature:Concentrated spray formula
- Additional Feature:Ideal for summer growth
- Additional Feature:Works on all grasses
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St. Augustine Liquid Lawn Food
When your grass needs a little extra encouragement to fill in thin spots, this liquid concentrate is a smart choice. It is packed with high nitrogen levels to push new runners and improve your lawn density without a heavy, bulky bag.
It makes the process of feeding your lawn feel like watering your plants, which is a nice change of pace. Just remember that because it is a smaller 8-ounce container, it is best suited for targeted treatment or smaller lawns rather than massive estates.
- Brand Name:St. Augustine
- Formula Type:Liquid
- Bag Weight:8 oz
- Key Ingredient:Nitrogen
- Specific Purpose:Thicker growth
- Additional Feature:Supports root health
- Additional Feature:Fast nutrient delivery
- Additional Feature:Simple mixing instructions
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Sunniland Phosphorus Free Lawn Fertilizer
If your soil is already rich in phosphorus, adding more can actually disrupt the natural balance of your local water supply. This formula avoids phosphorus entirely, focusing on slow release nitrogen to provide a steady, consistent feeding that won't cause your grass to grow too fast and weak.
This is a great pick if you want a consistent performer that keeps your lawn fed over several weeks. Be aware that the lack of phosphorus means it is not designed to help with new seeding or deep root establishment in brand-new lawns.
- Brand Name:Sunniland
- Formula Type:Granular
- Coverage Area:5,000 sq ft per bag
- Bag Weight:20 lb (2 pack)
- Specific Purpose:Slow release feeding
- Additional Feature:Steady nutrient release
- Additional Feature:Professional grade results
- Additional Feature:Safe for established turf
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SeedRanch St. Augustine 24-2-11 Fertilizer
Sometimes you need a substantial amount of product to handle a large property, and this 50-pound bag is built for the task. With a high nutrient content, it delivers a strong punch of food that helps your grass maintain a deep, healthy color even through stressful weather.
It is a serious option for homeowners who take their lawn care seriously and don't want to run back to the store every weekend. Because of its weight, ensure you have a reliable spreader ready to distribute the weight evenly across your yard.
- Brand Name:SeedRanch
- Formula Type:Granular
- Bag Weight:50 lbs
- Specific Purpose:General lawn health
- Additional Feature:Promotes vibrant greening
- Additional Feature:Consistent granule size
- Additional Feature:Ideal for large lawns
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Scotts Turf Builder Lawn Food
You have likely seen this blue bag in every neighborhood because it is a reliable, all-around staple for many homeowners. It is designed to work with all grass types, providing the baseline nutrition needed to keep your lawn looking respectable throughout the season.
It acts like a dependable daily multivitamin for your soil. While it is excellent for general maintenance, it lacks specific weed or pest-fighting additions, so keep that in mind if you are dealing with a larger infestation.
- Brand Name:Scotts
- Formula Type:Granular
- Coverage Area:5,000 sq ft
- Bag Weight:12.5 lbs
- Specific Purpose:All purpose feeding
- Additional Feature:Improves root strength
- Additional Feature:Simple application
- Additional Feature:Encourages uniform growth
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Scotts EZ Patch Repair Mix
We all have those frustrating bare spots that refuse to fill in no matter how much we fertilize the surrounding area. This mix is a clever two-in-one solution that combines mulch and fertilizer to protect new growth and feed the soil at the same time.
Using this feels like giving your lawn a targeted bandage, helping it heal before the weeds move in. It is not intended for the whole yard, so save this exclusively for those stubborn, high-traffic patches that need extra attention.
- Brand Name:Scotts
- Formula Type:Mulch and fertilizer
- Coverage Area:170 sq ft
- Bag Weight:3.75 lb (2 pack)
- Specific Purpose:Lawn repair
- Additional Feature:Easy to spread
- Additional Feature:Retains moisture
- Additional Feature:Encourages quick recovery
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Scotts SummerGuard Lawn Food
Summer heat brings more than just wilting grass; it invites unwanted insects to take up residence in your lawn. This product is a dual-threat, providing the essential nutrients your grass needs to survive the heat while also acting as a killer for common lawn pests.
It is a fantastic way to simplify your mid-summer routine by combining two tasks into one. Just make sure to water it in properly after application to ensure the ingredients reach the soil and the pests hiding beneath the blades.
- Brand Name:Scotts
- Formula Type:Granular
- Coverage Area:5,000 sq ft
- Bag Weight:13.35 lbs
- Specific Purpose:Feeding and pest control
- Additional Feature:Targets surface insects
- Additional Feature:Promotes heat tolerance
- Additional Feature:Standardized release
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Superior 15-0-15 Liquid Fertilizer
This liquid formula is a bit more sophisticated than standard food because it includes humic acid, fish, and seaweed. These ingredients go beyond simple growth to improve your soil health, making it an excellent choice for folks who want to treat the ground beneath the grass.
It is like adding a nutrient-rich compost tea to your yard without the mess. The attached sprayer makes it very simple to use, though you will want to store the sprayer carefully so it doesn't leak between uses.
- Brand Name:Simple Lawn Solutions
- Formula Type:Liquid
- Bag Weight:32 Ounce
- Key Ingredient:Potassium, Humic, Fish, Seaweed
- Specific Purpose:Growth and greening
- Additional Feature:All season formula
- Additional Feature:Improves root uptake
- Additional Feature:Professional grade blend
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LESCO Weed and Feed
If you want to move up to a professional level of maintenance, this is the product landscape pros often reach for. It uses Penoxsulam to tackle weeds, providing a much more robust response to invasive plants than your average big-box store variety.
This is a heavy-duty bag meant for serious results on established St. Augustine grass. Since it is commercial-grade, be extra careful to follow the application rates exactly to avoid any accidental over-application in sensitive areas.
- Brand Name:LESCO
- Formula Type:Granular
- Bag Weight:50 lb
- Key Ingredient:Penoxsulam
- Specific Purpose:Weed and feed
- Additional Feature:Long lasting control
- Additional Feature:Large area capacity
- Additional Feature:Professional formula
Frequently Asked Questions
How often should I fertilize my Saint Augustine lawn?
You should aim to fertilize about four to six times during the active growing season. Start in early spring once the grass has fully greened up and stop about six weeks before the first expected frost in the fall.
Will fertilizer help if my lawn is in the shade?
Shade-grown grass needs significantly less fertilizer than grass sitting in full sun. If you apply the same amount of nitrogen to a shaded area, you risk encouraging fungal issues and weak, spindly growth. Reduce your application rate by half in those darker corners of your yard.
Why does my grass turn yellow after I apply fertilizer?
Yellowing often happens if you apply too much product at once, which causes fertilizer burn. It can also occur if the nitrogen is not balanced with enough micronutrients like iron or magnesium. Water your lawn thoroughly after application to help the nutrients move into the soil instead of sitting on the leaf blades.
Can I use a general-purpose lawn fertilizer?
Most general-purpose fertilizers contain herbicides that are lethal to Saint Augustine. If the bag does not explicitly state it is safe for your grass type, leave it on the shelf. You are better off buying a specialized blend intended for warm-season grasses.
Should I water before or after I fertilize?
You should always water your lawn after applying granules to wash the nutrients down to the root zone. However, make sure the grass blades are dry when you apply the fertilizer to prevent the granules from sticking to wet leaves. This simple step protects your lawn from potential chemical burns.
