Many homeowners assume that all grass needs is a simple dose of water to stay healthy. In reality, St. Augustine is a hungry, demanding grass that requires specific nutrient ratios to survive the heat.
Choosing the Best Lawn Fertilizers for St Augustine Grass is about more than just grabbing the first bag you see on the shelf. You need to understand what your soil is missing before you apply anything. Let us walk through the top options to ensure your yard stays healthy all season.
Key Takeaways
- Prioritize formulas with a high nitrogen content to support the lush, dark green blades characteristic of healthy St. Augustine.
- Choose slow release granular options if you want to feed your lawn consistently over several weeks without the risk of burning the turf.
- Opt for liquid applications when you need an immediate boost of color or a rapid recovery from stress in your lawn.
- Check the phosphorus levels on the bag, as some regions restrict this nutrient due to its environmental impact on local waterways.
- Verify whether the product includes herbicide for weed control or if it is purely focused on feeding the soil to improve grass density.
| Best Overall Choice |  |
Sunniland St. Augustine Weed and Feed | Dual action performance | St. Augustine specific | Efficient weed control | View on Amazon | Read Review |
| Optimal Spring Booster |  |
Simple Lawn Solutions 16-4-8 Liquid Fertilizer | Fast acting liquid | Versatile nutrient profile | Easy spray application | View on Amazon | Read Review |
| Greening Specialist |  |
Sunniland St. Augustine Phosphorus Free Fertilizer | Phosphorus free formula | Slow release nitrogen | Large coverage capacity | View on Amazon | Read Review |
| Quick Color Enhancer |  |
St. Augustine Liquid Lawn Food | Rapid nutrient delivery | Promotes thick growth | Encourages new runners | View on Amazon | Read Review |
| Dependable Turf Foundation |  |
Scotts Turf Builder Lawn Food | Consistent growth results | Widely available formula | Reliable brand quality | View on Amazon | Read Review |
| Broadleaf Weed Fighter |  |
Scotts Turf Builder Weed and Feed | Controls common weeds | Feeds existing grass | Trusted industry formula | View on Amazon | Read Review |
| Seasonal Pest Shield |  |
Scotts SummerGuard Lawn Food | Combined pest control | Summer stress support | Easy granular application | View on Amazon | Read Review |
| Iron-Rich Color Booster |  |
Scotts Liquid Green Max | High iron content | Rapid greening results | Liquid application ease | View on Amazon | Read Review |
| Nutrient Dense All-Rounder |  |
Superior 15-0-15 Liquid Lawn Fertilizer | Added humic acid | Fish and seaweed nutrients | Includes spray attachment | View on Amazon | Read Review |
| Low Maintenance Solution |  |
Pennington Full Season Fertilizer | Once per season | Slow release technology | High nitrogen content | View on Amazon | Read Review |
More Details on Our Top Picks
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Sunniland St. Augustine Weed and Feed
This is your go-to solution if you struggle with persistent weeds alongside your St. Augustine. By combining a targeted herbicide with essential nutrients, it allows you to treat your lawn and fertilize in one efficient pass.
The formula is specifically tailored for the unique needs of St. Augustine varieties. Just be mindful that it is designed for a specific application rate, so ensure your spreader is calibrated correctly before you head out.
- Brand:Sunniland
- Product Type:Granular Weed and Feed
- Coverage Area:5,000 square feet
- Additional Feature:Kills broadleaf weeds
- Additional Feature:Promotes dense growth
- Additional Feature:Easy granular application
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Simple Lawn Solutions 16-4-8 Liquid Fertilizer
When you need to jumpstart your lawn as the weather warms, this balanced liquid formula is an excellent pick. The 16-4-8 ratio provides a steady supply of nitrogen, which acts like a jolt of energy for your grass after a long dormancy.
Because it is a liquid, your lawn absorbs the nutrients almost immediately. It works well if you have a hose-end sprayer ready to go, though you will need to reapply more frequently than you would with granular options.
- Brand:Simple Lawn Solutions
- Product Type:Liquid Fertilizer
- Nutrient Ratio:16-4-8
- Packaging Weight:32 ounces
- Additional Feature:High nitrogen content
- Additional Feature:Suitable for all grasses
- Additional Feature:Concentrated formula
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Sunniland St. Augustine Phosphorus Free Fertilizer
If your soil already has enough phosphorus, this 20-0-6 granular blend keeps your grass green without adding unnecessary chemicals to your local water runoff. It relies on slow release nitrogen, providing a steady meal rather than a quick sugar rush that might fade in a week.
This is a great choice for homeowners who prioritize environmental health in their landscaping routine. Keep in mind that you need to water this in well to activate the slow release mechanism.
- Brand:Sunniland
- Product Type:Granular Fertilizer
- Coverage Area:5,000 square feet
- Nutrient Ratio:20-0-6
- Packaging Weight:20 pounds
- Additional Feature:Promotes steady growth
- Additional Feature:Minimal burn risk
- Additional Feature:Two bag pack
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St. Augustine Liquid Lawn Food
Sometimes your lawn just looks a little tired, and this liquid food acts like a quick pick-me-up for your turf. It is formulated to encourage new runners, which helps fill in thin patches and creates a more carpet-like appearance.
It is particularly useful if you want to see visible results without waiting weeks for granular pellets to break down. Just remember that this is a supplement, not a full replacement for a structured seasonal feeding program.
- Brand:St. Augustine
- Product Type:Liquid Fertilizer
- Packaging Weight:8 ounces
- Additional Feature:High nitrogen formula
- Additional Feature:Supports root health
- Additional Feature:Easy to mix
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Scotts Turf Builder Lawn Food
You probably recognize this classic orange bag, and for good reason, as it serves as a reliable baseline for any lawn care routine. It provides the core minerals necessary for consistent growth across all grass types, including St. Augustine.
Think of this as the daily multivitamin for your yard. It is very accessible and easy to find, though it lacks the specialized weed-fighting power found in more aggressive blends.
- Brand:Scotts
- Product Type:Granular Fertilizer
- Coverage Area:5,000 square feet
- Packaging Weight:12.5 pounds
- Additional Feature:Improves root strength
- Additional Feature:All-season use
- Additional Feature:Simple spreader application
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Scotts Turf Builder Weed and Feed
When dandelions and clover start taking over your yard, this product helps you reclaim your space while feeding the grass. It is a dual-purpose tool that allows you to address unwanted invaders without needing to buy two separate products.
It is highly effective at thinning out those pesky patches that ruin a uniform look. Just be sure to apply it when the foliage is damp, as the weed killer needs to stick to the leaves to do its job.
- Brand:Scotts
- Product Type:Granular Weed and Feed
- Coverage Area:5,000 square feet
- Packaging Weight:14.29 pounds
- Additional Feature:Eliminates dandelion
- Additional Feature:Removes clover
- Additional Feature:Promotes dense turf
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Scotts SummerGuard Lawn Food
Summer heat often invites unwanted insects to feast on your lawn, but this integrated solution solves two problems at once. It provides the nutrients your grass needs to handle the summer stress while keeping pests under control.
This saves you the headache of managing insects separately during the peak of the season. It is a smart maintenance step for anyone who deals with lawn-damaging bugs every year.
- Brand:Scotts
- Product Type:Fertilizer and Insecticide
- Coverage Area:5,000 square feet
- Packaging Weight:13.35 pounds
- Additional Feature:Kills lawn insects
- Additional Feature:Strengthens grass roots
- Additional Feature:Simple application process
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Scotts Liquid Green Max
If your grass is green but you want it to look truly vibrant, this iron supplement is your best friend. It acts like a polishing agent, transforming a dull lawn into a deep, dark green that catches the eye.
Because it is a 2-in-1 formula, you get the benefit of nitrogen for growth and iron for color. It works on any grass type, but it really shines on St. Augustine lawns that are healthy but lacking that extra visual pop.
- Brand:Scotts
- Product Type:Liquid Fertilizer
- Packaging Weight:32 ounces
- Additional Feature:Iron supplement
- Additional Feature:Fast absorption
- Additional Feature:Suitable for all grasses
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Superior 15-0-15 Liquid Lawn Fertilizer
This liquid mix stands out because it goes beyond standard nitrogen, adding humic acid, fish, and seaweed to the recipe. It is a more holistic approach to feeding your soil biology, which leads to better long-term health.
The attached sprayer makes it incredibly easy to use, as you just plug in your hose and go. It is a great choice if you want to support your lawn's root system as much as its outward appearance.
- Brand:Simple Lawn Solutions
- Product Type:Liquid Fertilizer
- Nutrient Ratio:15-0-15
- Packaging Weight:32 ounces
- Additional Feature:Promotes root growth
- Additional Feature:All-season formula
- Additional Feature:Easy hose connection
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Pennington Full Season Fertilizer
If your schedule is packed, this formula is a blessing in disguise because you only need to apply it once per season. It uses a slow release technology that meters out nutrition exactly when your grass needs it, eliminating the guesswork.
It is a high-nitrogen blend that keeps your grass growing steadily for months. You get to spend less time in the garage with your spreader and more time enjoying your yard.
- Brand:Pennington
- Product Type:Granular Fertilizer
- Nutrient Ratio:32-0-5
- Packaging Weight:11.2 pounds
- Additional Feature:Consistent greening
- Additional Feature:Supports long-term growth
- Additional Feature:Easy application schedule
Frequently Asked Questions
How much fertilizer should I apply per thousand square feet?
Most experts recommend applying about one pound of nitrogen per 1,000 square feet during each application. Check the guaranteed analysis on the bag to calculate how much product you actually need to reach that number. Divide the number 100 by the first digit of the NPK ratio on your bag. This tells you exactly how many pounds of product you need to spread to hit that one-pound nitrogen target.
Will a high-nitrogen fertilizer cause fungus in my lawn?
Yes, if you overdo it, you can create a buffet for fungal growth. Excess nitrogen creates lush, succulent blades that are prime targets for diseases like gray leaf spot or brown patch. Stick to the recommended application rates on the packaging to avoid pushing the grass too hard. Proper watering practices also prevent the moisture buildup that fungi love.
Can I use a fertilizer meant for Bermuda grass on my St. Augustine?
You should avoid doing this because Bermuda grass fertilizers often contain higher concentrations of herbicides that St. Augustine cannot tolerate. These products act like a poison to your lawn rather than a meal. Always confirm that your specific variety is listed on the bag. If you cannot find a clear label, play it safe and buy a product formulated specifically for your turf type.
Should I water after applying fertilizer?
Absolutely, because water is the delivery vehicle that carries nutrients down to the root zone. Without irrigation or rainfall, the fertilizer granules will just sit on the surface where they can evaporate or burn the leaves. Aim to provide about a quarter-inch of water immediately after application. This helps move the product into the soil where it can do its job.
Why is my grass turning yellow even after I fertilized it?
This is a classic sign of an iron deficiency or a soil pH that is too high. If the soil is too alkaline, the plant cannot pull iron from the ground, which leads to chlorosis or yellowing leaves. Try applying a liquid iron supplement as a quick fix to green up the blades. Then, consider adding elemental sulfur to your soil care routine to fix the pH issue permanently.
