Most homeowners assume that grass growth is merely a function of water and sunlight. In reality, St. Augustine is a demanding prima donna that starves quickly without precise nutritional intervention.
Providing the right balance of nitrogen and iron acts like a jumper cable for a dormant lawn. These choices for the Best Fertilizers for St. Augustine Grass help you manage the transition from yellow patches to a carpet of deep, vibrant color.
Key Takeaways
- Prioritize slow-release nitrogen formulas to ensure your lawn receives a steady supply of nutrients rather than a brief, unsustainable spike.
- Always verify that the fertilizer is phosphorus-free if you live near local waterways to avoid environmental runoff issues.
- Select products containing Atrazine if you need to tackle broadleaf weeds while simultaneously feeding the healthy grass blades.
- Check for added iron in the ingredient list to achieve that deep, dark green hue without forcing excessive vertical growth.
- Match the coverage area listed on the bag to your actual lawn size to prevent over-application and potential turf burn.
| Best All-Rounder |  |
Sunniland St. Augustine Weed and Feed | Dual action formula | Clears common lawn weeds | Sustained green growth | View on Amazon | Read Review |
| Rapid Growth Booster |  |
St. Augustine Liquid Lawn Food | Fast nutrient uptake | Encourages new runners | Deep green color | View on Amazon | Read Review |
| Steady Nutrient Provider |  |
Sunniland Slow Release Granular Fertilizer | Slow release nitrogen | Phosphorus free | Consistent feeding | View on Amazon | Read Review |
| Iron Rich Formula |  |
Fertilome 15-0-15 Centipede and St. Augustine | High iron content | Corrects yellowing blades | Balanced nutrient ratio | View on Amazon | Read Review |
| Color Enhancement Specialist |  |
Scotts Green Max Lawn Food | Rapid greening | High iron content | Visible results quickly | View on Amazon | Read Review |
| Versatile Liquid Feed |  |
Simple Lawn Solutions Balanced Fertilizer | Balanced NPK ratio | Versatile across grass types | Concentrated liquid spray | View on Amazon | Read Review |
| Seasonal Maintenance Staple |  |
Scotts Turf Builder Lawn Food | Reliable growth | All season use | Simple application | View on Amazon | Read Review |
| Broadleaf Weed Fighter |  |
Scotts Turf Builder Weed and Feed | Targets dandelions | Controls clover | Feeds grass simultaneously | View on Amazon | Read Review |
| Bulk Application Choice |  |
SeedRanch St. Augustine High-Yield Fertilizer | Large bag size | High nitrogen content | Formulated for St. Augustine | View on Amazon | Read Review |
| Pre-Emergent Weed Barrier |  |
Fertilome St. Augustine Weed and Feed | Includes Atrazine | Pre-emergent control | Post-emergent control | View on Amazon | Read Review |
More Details on Our Top Picks
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Sunniland St. Augustine Weed and Feed
This is the go-to choice for homeowners who want to handle two jobs at once. It combines fertilizer with herbicide to keep your grass fed while knocking back pesky invaders.
It works effectively on established lawns that need a bit of extra help. Just keep in mind that since it contains weed control, you should avoid using it near flowers or garden beds where you want those plants to stay put.
- Brand:Sunniland
- Coverage:5,000 sq ft
- Packaging Size:15 lb bag
- Additional Feature:Kills existing weeds
- Additional Feature:Feeds grass roots
- Additional Feature:Promotes thick turf
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St. Augustine Liquid Lawn Food
Liquid formulas act like a quick infusion of energy for your soil. If your grass looks thin or needs a boost to fill in bare spots, this spray provides the nutrients directly to the blades for faster absorption.
Because it is a liquid, you will need a hose-end sprayer to apply it evenly. It is an excellent supplement for maintaining that deep, rich color throughout the growing season.
- Brand:St. Augustine
- Type:Liquid
- Packaging Size:1 Gallon
- Additional Feature:Promotes thicker growth
- Additional Feature:Easy to apply
- Additional Feature:Fast acting formula
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Sunniland Slow Release Granular Fertilizer
You want a fertilizer that feeds your lawn over time rather than all at once. This slow-release nitrogen mix gives your grass a consistent diet, which helps prevent those awkward surges in growth that require constant mowing.
By leaving out the phosphorus, it stays mindful of local runoff regulations. It is a solid, no-nonsense choice for anyone focused purely on nitrogen-heavy lawn health.
- Brand:Sunniland
- Coverage:5,000 sq ft
- Nutrient Ratio:20-0-6
- Packaging Size:20 lb bags
- Additional Feature:Longer lasting results
- Additional Feature:Environmentally conscious formula
- Additional Feature:Granular application
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Fertilome 15-0-15 Centipede and St. Augustine
St. Augustine grass often struggles with chlorosis, which makes the blades look yellow and sickly. This mix includes a high iron content specifically to correct that color loss and bring back a deep, healthy green.
The balanced ratio is gentle enough for warm-season grasses. It is a smart pick if your soil is already sufficient in phosphorus but needs a kick to improve leaf color and density.
- Brand:Fertilome
- Nutrient Ratio:15-0-15
- Packaging Size:16 lbs
- Additional Feature:Prevents nutrient deficiency
- Additional Feature:Supports dense growth
- Additional Feature:Safe for warm-season grasses
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Scotts Green Max Lawn Food
If your primary goal is to make your neighbors jealous of your lawn's color, start here. This formula uses a dual-action approach to feed the grass while delivering an immediate iron supplement.
You will see results in the color of your grass within just a few days of application. It is less about aggressive weed control and more about achieving that lush, vibrant aesthetic that turns heads.
- Brand:Scotts
- Coverage:5,000 sq ft
- Packaging Size:16.67 lbs
- Additional Feature:Iron supplement included
- Additional Feature:Enhances chlorophyll production
- Additional Feature:Professional lawn aesthetic
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Simple Lawn Solutions Balanced Fertilizer
This liquid formula is a Swiss Army knife for your yard. It works on any grass type, making it a great option if you have a mix of St. Augustine and other varieties in your landscape.
The balanced NPK ratio covers all the basic needs for spring and summer growth. Just remember that liquids require more frequent applications than granules to keep the nutrient levels topped up.
- Brand:Simple Lawn Solutions
- Type:Liquid
- Nutrient Ratio:16-4-8
- Packaging Size:32 Ounce
- Additional Feature:Spring and summer use
- Additional Feature:Easy spray application
- Additional Feature:Quality nutrient blend
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Scotts Turf Builder Lawn Food
This is the foundational product for many gardeners who want a predictable, reliable feeding schedule. It provides the standard nitrogen boost that St. Augustine needs to thrive through the hotter months of the year.
It is designed to be used anytime during the growing season. Since it is purely a fertilizer, you can combine it with separate weed or pest control products if your lawn has specific issues to address.
- Brand:Scotts
- Coverage:5,000 sq ft
- Packaging Size:12.5 lbs
- Additional Feature:Strengthens grass roots
- Additional Feature:Improves overall health
- Additional Feature:Consistent nutrient delivery
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Scotts Turf Builder Weed and Feed
Some lawns are magnets for dandelions and clover. This product acts as a targeted weapon against those intruders while simultaneously fueling your St. Augustine grass to help it crowd out future invaders.
The granular application is straightforward, though you need to make sure the grass is slightly damp so the weed control particles stick to the leaves. It is an efficient way to tidy up a messy lawn in one go.
- Brand:Scotts
- Coverage:5,000 sq ft
- Packaging Size:14.29 lbs
- Additional Feature:Weed killer and fertilizer
- Additional Feature:Thickens lawn density
- Additional Feature:Easy granular distribution
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SeedRanch St. Augustine High-Yield Fertilizer
If you are managing a large property, buying small bags is a headache. This 50-pound bag provides a high-potency nitrogen blend that is formulated specifically for the needs of St. Augustine varieties.
The 24-2-11 ratio ensures your grass has plenty of fuel for heavy growth. You will appreciate the value of having a large supply on hand for multiple applications throughout the long summer.
- Brand:SeedRanch
- Nutrient Ratio:24-2-11
- Packaging Size:50 lbs
- Additional Feature:High-yield performance
- Additional Feature:Designed for large lawns
- Additional Feature:Long-lasting supply
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Fertilome St. Augustine Weed and Feed
This is a more technical solution for those who want to get ahead of the weed cycle. It contains Atrazine, which not only kills existing weeds but acts as a barrier to stop new ones from sprouting.
It is a specialized product that requires careful following of the label instructions. Use this if you are tired of playing catch-up with seasonal weeds and want a more proactive defense for your turf.
- Brand:Fertilome
- Nutrient Ratio:15-0-4
- Packaging Size:25.6 lbs
- Additives:Atrazine
- Additional Feature:Weed suppression barrier
- Additional Feature:Safe for Zoysia/St. Augustine
- Additional Feature:Granular delivery system
Frequently Asked Questions
How often should I fertilize my St. Augustine lawn?
You should feed your lawn every 6 to 8 weeks during the active growing season. Start your first application once the grass has fully greened up in the spring. Stop fertilizing at least six weeks before the first expected frost in your area.
Can I fertilize if my grass is wet?
It is best to apply granular fertilizer when the grass is dry but the soil is moist. If the grass is soaked, the granules may stick to the blades and cause chemical burns. Always water your lawn lightly after application to wash the nutrients down into the root zone.
Will fertilizer kill my St. Augustine grass if I apply too much?
Yes, over-application creates a salt buildup that dehydrates the root system. This usually appears as brown, scorched patches in your yard. Always follow the bag rate and use a spreader calibrated to your specific model to ensure even coverage.
Should I mulch my clippings instead of bagging them?
Mulching is an excellent way to return natural nutrients to the soil. Grass clippings act like a vitamin supplement for your lawn, providing up to 25 percent of the nitrogen your grass needs. This reduces the amount of synthetic fertilizer you need to buy each year.
Is it safe for my pets to walk on the lawn after fertilizing?
You should keep pets and children off the area until the fertilizer has been fully watered in and the grass blades are dry. Check the manufacturer label for specific wait times regarding pet safety. Most products are safe once the pellets have dissolved into the soil.
