St. Augustine grass is famously temperamental. Feeding it requires precision because the wrong ratio of nitrogen to iron can either leave your lawn starving or cause a surge of growth that invites pests. Understanding your soil needs is the most important step in finding the Best Fertilizers for St. Augustine Grass.
Matching your specific maintenance goals to the right chemical composition prevents common yard headaches. A healthy lawn is like a well-oiled machine, and fertilizer is the fuel that keeps it running smoothly. Let me help you find the right supplies to get your grass looking its best this season.
Key Takeaways
- Prioritize formulas that specify a high nitrogen content with iron to encourage that deep green color without forcing excessive, weak growth.
- Verify whether your lawn currently suffers from broadleaf weeds, as you should only use products containing Atrazine if active control is required.
- Choose between granular and liquid application based on how much coverage you need and how quickly you want the nutrients to reach the root zone.
- Check the phosphorus levels carefully, especially if you reside in a region with strict environmental regulations regarding runoff into local waterways.
- Look for slow release nitrogen formulations to ensure your turf receives a consistent supply of food over several weeks rather than a sudden, fleeting spike.
| Premier Weed Defense |  |
Sunniland St. Augustine Weed and Feed | Combats broadleaf weeds effectively | Encourages rapid turf thickening | Simple granular application | View on Amazon | Read Review |
| Rapid Growth Booster |  |
St. Augustine Liquid Lawn Food | Promotes faster runner expansion | Delivers immediate nutrient uptake | Enhances deep green pigment | View on Amazon | Read Review |
| Steady Sustained Growth |  |
Sunniland Slow Release Nitrogen Fertilizer | Provides long-lasting feeding | Contains zero phosphorus | Reliable granular distribution | View on Amazon | Read Review |
| Iron-Rich Color Enhancer |  |
Fertilome Centipede and St. Augustine Fertilizer | High iron for deep color | Balanced nutrient profile | Supports root health | View on Amazon | Read Review |
| Iron-Infused Greening Agent |  |
Scotts Green Max Lawn Food | Rapid greening effect | Easy to spread evenly | Iron supplement included | View on Amazon | Read Review |
| Versatile Seasonal Liquid |  |
Simple Lawn Solutions Balanced Liquid | Highly versatile formula | Concentrated liquid value | Works on all grasses | View on Amazon | Read Review |
| Reliable General Maintenance |  |
Scotts Turf Builder Lawn Food | Trusted, proven formulation | Strengthens against heat | Simple to apply | View on Amazon | Read Review |
| Common Weed Eradicator |  |
Scotts Turf Builder Weed and Feed | Effectively kills dandelion/clover | Feeds grass simultaneously | Wide coverage per bag | View on Amazon | Read Review |
| High-Volume Bulk Feed |  |
SeedRanch St. Augustine Heavy Duty Fertilizer | High-volume bulk size | Potent nitrogen boost | Excellent for larger yards | View on Amazon | Read Review |
| Proactive Weed Manager |  |
Fertilome St. Augustine Weed and Feed | Pre and post-emergent control | Contains Atrazine herbicide | Safe for St. Augustine | 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 tackle pesky weeds while simultaneously fueling your lawn, this granular choice is your best bet. It functions like a dual-action shield, knocking back unwanted broadleaf weeds while pushing your grass toward a thicker, healthier state.
You should opt for this if your St. Augustine lawn looks a bit patchy and prone to invasive intruders. Keep in mind that you must apply it carefully to avoid contact with non-target plants, as the herbicide component is quite active.
- Brand Name:Sunniland
- Product Type:Granular Weed and Feed
- Coverage Area:5,000 square feet
- Additional Feature:Targeted broadleaf herbicide
- Additional Feature:Nitrogen-rich growth formula
- Additional Feature:Convenient bag packaging
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St. Augustine Liquid Lawn Food
Liquid applications act like a quick infusion of nutrients for thirsty roots. This formula focuses specifically on generating new runners and maintaining that deep, characteristic green color that St. Augustine owners crave.
This is a fantastic pick if your lawn needs a mid-season pick-me-up or if you prefer the ease of a hose-end sprayer. Be aware that because it is a liquid, you will likely need to reapply more frequently than you would with slow-release granules.
- Brand Name:St Augustine Grass Fertilizer
- Product Type:Liquid Lawn Food
- Additional Feature:Fast-acting liquid formulation
- Additional Feature:Encourages lateral spread
- Additional Feature:Easy hose-end application
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Sunniland Slow Release Nitrogen Fertilizer
Consistency is the heartbeat of a healthy lawn, and this formula provides exactly that. By utilizing slow-release nitrogen, it feeds your grass over an extended duration, which prevents the dreaded "boom and bust" cycle of rapid growth followed by starvation.
Since it is phosphorus-free, it is an environmentally conscious choice for soils that already have sufficient phosphorus levels. Just remember that it takes a little longer to show initial results compared to liquid alternatives.
- Brand Name:Sunniland
- Product Type:Slow-release granular
- Coverage Area:5,000 square feet
- Nutrient Ratio:20-0-6
- Additional Feature:Sustained release nitrogen
- Additional Feature:Prevents nutrient leaching
- Additional Feature:Two-pack bundle
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Fertilome Centipede and St. Augustine Fertilizer
If your grass looks a bit pale, the high iron content here will turn things around quickly. This 15-0-15 ratio is specifically designed for warm-season grasses that require a careful balance of nutrients to thrive without excessive leaf growth.
The inclusion of slow-release nitrogen ensures your lawn remains healthy for weeks after the initial application. It is a solid choice for those who want a lush, deep green look without forcing their lawn to grow too aggressively.
- Brand Name:Fertilome
- Product Type:Granular Fertilizer
- Nutrient Ratio:15-0-15
- Additional Feature:High iron supplement
- Additional Feature:Slow-release nitrogen source
- Additional Feature:Suitable for warm-season lawns
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Scotts Green Max Lawn Food
This product acts like a jolt of energy for a dull-looking lawn. It combines traditional nitrogen fertilization with a potent iron supplement to ensure your grass looks vibrant, often showing a color change in just a few days.
It is ideal for anyone who wants a quick visual improvement without worrying about weed control. However, because it works so quickly, do not expect it to provide the long-term, slow-feeding benefits that other professional-grade granular products offer.
- Brand Name:Scotts
- Product Type:Granular Lawn Food
- Coverage Area:5,000 square feet
- Additional Feature:Iron-fortified formula
- Additional Feature:Fast-acting nutrients
- Additional Feature:Consistent granule size
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Simple Lawn Solutions Balanced Liquid
Flexibility is the name of the game with this balanced liquid fertilizer. Whether you are prepping for spring growth or maintaining health in the height of summer, this concentrated spray provides a precise dose of nitrogen, phosphorus, and potassium.
Since it works on any grass type, it is a great staple to keep in the garage if you have mixed landscaping. You will appreciate how easily it mixes with water, though you must use it as a supplement rather than a complete replacement for granular feeding.
- Brand Name:Simple Lawn Solutions
- Product Type:Liquid Fertilizer
- Nutrient Ratio:16-4-8
- Additional Feature:Easy hose-end spray
- Additional Feature:Balanced NPK ratio
- Additional Feature:Spring and summer utility
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Scotts Turf Builder Lawn Food
Sometimes you just need a standard, high-quality feed to keep things ticking along nicely. This is the classic choice for homeowners who want a predictable, effective product that won't require a degree in soil science to apply correctly.
It is designed to help your grass withstand the stresses of heat and drought, which is vital for St. Augustine owners in warmer climates. Do not look for weed control here, as this is purely a nutritional product for the turf itself.
- Brand Name:Scotts
- Product Type:Granular Fertilizer
- Coverage Area:5,000 square feet
- Additional Feature:Heat stress resistance
- Additional Feature:Consistent growth results
- Additional Feature:Wide availability
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Scotts Turf Builder Weed and Feed
This is the go-to solution for lawns plagued by dandelions and clover. By combining fertilizer with a post-emergent herbicide, it cleans up your lawn’s appearance while providing the food necessary for the grass to fill in the gaps left by dying weeds.
Be very careful with your application timing, as this product works best when the foliage is damp so the granules can stick to the weeds. Avoid using this if you have recently planted new grass seed, as it can inhibit germination.
- Brand Name:Scotts
- Product Type:Granular Weed and Feed
- Coverage Area:5,000 square feet
- Additional Feature:Post-emergent weed control
- Additional Feature:Targeted broadleaf herbicide
- Additional Feature:Encourages turf thickening
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SeedRanch St. Augustine Heavy Duty Fertilizer
If you manage a large property, buying a 50-pound bag is a smarter way to handle your lawn care needs. This concentrated formula provides a significant nitrogen boost that is ideal for hungry St. Augustine runners that need to cover a lot of ground.
The 24-2-11 ratio is quite potent, so you must be precise with your spreader settings to avoid burning the lawn. It is a workhorse product designed for those who prefer to buy in bulk rather than running to the store every month.
- Brand Name:SeedRanch
- Product Type:Granular Fertilizer
- Nutrient Ratio:24-2-11
- Additional Feature:Bulk packaging
- Additional Feature:High nitrogen content
- Additional Feature:Professional grade utility
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Fertilome St. Augustine Weed and Feed
This granular treatment uses Atrazine to provide both pre-emergent and post-emergent control. This means it kills existing weeds and stops new ones from germinating, acting like a security system for your lawn.
It is specifically tailored for St. Augustine, so you do not have to worry about the chemical being too harsh for your grass. Keep in mind that this is a heavy-duty product, so follow the application instructions exactly to maintain the health of your soil.
- Brand Name:Fertilome
- Product Type:Granular Weed and Feed
- Nutrient Ratio:15-0-4
- Key Ingredient:Atrazine
- Additional Feature:Prevents new weeds
- Additional Feature:Kills existing broadleaf
- Additional Feature:Specialized grass safety
Frequently Asked Questions
How often should I fertilize my St. Augustine grass?
You should aim to feed your lawn every six to eight weeks during the active growing season. Start your first application once the grass has fully greened up in the spring and stop before the first frost in the fall.
Will this fertilizer burn my lawn?
Fertilizer burn usually happens when you apply too much product or fail to water it in properly. Always follow the application rate on the bag and run your sprinklers immediately after spreading the granules to wash them down to the soil.
Can I fertilize while the grass is wet?
It is generally better to apply fertilizer to dry grass so the granules do not stick to the blades and cause localized burning. However, the soil itself should have some moisture, or you should be prepared to irrigate right after the application.
Why is my lawn still yellow after fertilizing?
Yellowing often points to an iron deficiency or an incorrect soil pH level. If your pH is too high, the grass cannot absorb the nutrients you are providing, so consider a soil test to see if you need to lower the alkalinity.
Is organic fertilizer better for St. Augustine?
Organic fertilizers improve the soil structure over time by adding beneficial microbes, though they work much slower than synthetic options. If you want a long term improvement in your lawn health, organic is a great choice, but you might need more patience to see the initial color change.
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