More fertilizer does not always mean a greener St. Augustine lawn. Excess nitrogen can push soft growth that struggles under heat, drought, and disease pressure, making timing and rate as important as the label’s promise.
That makes the Best Lawn Fertilizers for St Augustine Grass a surprisingly varied group, with products aimed at different lawn conditions and seasons. The comparison ahead separates the practical differences so you can read each option with a sharper eye.
Key Takeaways
- Compare N-P-K numbers first, and choose a formula suited to St. Augustine’s seasonal growth pattern.
- Check the stated coverage area to match the application rate with your lawn’s actual size.
- Favor slow-release nitrogen for steady feeding and less risk of rapid, weak growth.
- Match weed or insect control to a confirmed problem instead of applying extra treatments by default.
- Use repair mixes for thin or damaged patches, not as a substitute for regular lawn feeding.
| Weed Control Pick |  |
Sunniland Weed & Feed 5,000 Sq. Ft. | Combines feeding and weed control | Made for St. Augustine grass | Covers 5,000 square feet | View on Amazon | Read Review |
| Balanced Liquid Feed |  |
Simple Lawn Solutions 16-4-8 Liquid | Balanced 16-4-8 formula | Liquid concentrate format | Suitable for any grass | View on Amazon | Read Review |
| Slow Release Granules |  |
Sunniland St. Augustine Fertilizer 20-0-6 | Slow-release nitrogen | Phosphorus-free formula | Two-bag package | View on Amazon | Read Review |
| Fast Green Growth |  |
St. Augustine Liquid Lawn Food 8 Ounce | High-nitrogen formula | Promotes thicker growth | Compact liquid format | View on Amazon | Read Review |
| Spot Repair Specialist |  |
Scotts EZ Patch St. Augustine Repair | Designed for lawn repair | Includes mulch and fertilizer | Suits St. Augustine grass | View on Amazon | Read Review |
| Large Lawn Staple |  |
Scotts Turf Builder Lawn Food 12.5 Pounds | Covers 5,000 square feet | Works with all grass types | Large 12.5-pound bag | View on Amazon | Read Review |
| Iron Color Booster |  |
Scotts Liquid Green Max 2-in-1 | Adds iron supplementation | Supports greener lawn color | Liquid application format | View on Amazon | Read Review |
| Summer Pest Defense |  |
Scotts Turf Builder SummerGuard 5,000 Sq. Ft. | Includes insect control | Covers 5,000 square feet | Designed for summer use | View on Amazon | Read Review |
| High-Nitrogen Turf Feed |  |
SeedRanch St. Augustine Fertilizer 24-2-11 | High-nitrogen 24-2-11 formula | Made for St. Augustine | Generous 50-pound package | View on Amazon | Read Review |
| One-Application Convenience |  |
Pennington Full Season Fertilizer 32-0-5 | One application per season | Slow-release feeding | High-nitrogen 32-0-5 formula | View on Amazon | Read Review |
More Details on Our Top Picks
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Sunniland Weed & Feed 5,000 Sq. Ft.
For St. Augustine lawns that need feeding and weed management in one application, this Sunniland formula is a practical starting point. Its defining strengths are weed and feed convenience, St. Augustine compatibility, and 5,000-square-foot coverage.
The limitation is that the available product details do not identify the fertilizer analysis or list the specific weeds it targets. You should check the package label for application timing and weed-control restrictions before using it.
- Brand:Sunniland
- Product Type:Weed and feed
- Coverage:5,000 sq. ft.
- Grass Type:St. Augustine
- Additional Feature:Weed-control lawn treatment
- Additional Feature:Fertilizer included
- Additional Feature:Broad lawn coverage
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Simple Lawn Solutions 16-4-8 Liquid
Choose this concentrate if you prefer liquid application and want a balanced N-P-K formula for seasonal lawn care. The 16-4-8 analysis, 32-ounce bottle, and compatibility with any grass type give it broad appeal for spring and summer feeding.
Its main drawback is the lack of stated coverage in the available listing details. Because it is concentrated, you will need to follow the label’s dilution and application instructions carefully.
- Brand:Simple Lawn Solutions
- Product Type:Liquid fertilizer
- N-P-K Formula:16-4-8
- Package Size:32 ounces
- Grass Type:Any grass type
- Additional Feature:Spring and summer use
- Additional Feature:Concentrated spray formula
- Additional Feature:Easy liquid application
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Sunniland St. Augustine Fertilizer 20-0-6
This Sunniland option suits homeowners who want a granular fertilizer with slow-release nitrogen for St. Augustine turf. Its 20-0-6 formula is phosphorus-free, and the two-bag package provides a substantial supply for larger lawn-care schedules.
The tradeoff is a less immediate application than a liquid feed. You also need to confirm the total coverage you can expect from the two-pack, since the listing states 5,000 square feet per bag.
- Brand:Sunniland
- Product Type:Granular fertilizer
- N-P-K Formula:20-0-6
- Coverage:5,000 sq. ft. per bag
- Package Size:Two 20-pound bags
- Grass Type:St. Augustine
- Additional Feature:Granular lawn food
- Additional Feature:Designed for St. Augustine
- Additional Feature:Extended feeding format
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St. Augustine Liquid Lawn Food 8 Ounce
For targeted feeding, this compact liquid lawn food focuses on thicker growth, rich green color, and new St. Augustine runners. The high-nitrogen formula and fast nutrient delivery make it a sensible choice for small areas or lawns needing a quick feeding step.
The 8-ounce size is the clear limitation for broad lawn coverage. The listing does not provide a brand, N-P-K ratio, or stated coverage, so you should review the label before planning a full-yard application.
- Product Type:Liquid lawn fertilizer
- Package Size:8 ounces
- Grass Type:St. Augustine
- Additional Feature:Supports new runners
- Additional Feature:Promotes rich green color
- Additional Feature:Fast nutrient delivery
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Scotts EZ Patch St. Augustine Repair
Use this Scotts mix for bare patches, thin spots, and localized St. Augustine repairs rather than routine whole-lawn feeding. It combines repair mulch and fertilizer, giving damaged areas a material designed for lawn recovery in one package.
Coverage is limited to up to 170 square feet, so a two-pack will not replace a full-size fertilizer bag for large lawns. The listing also does not provide an N-P-K analysis, which limits direct comparison with standard lawn fertilizers.
- Brand:Scotts
- Product Type:Repair mulch and fertilizer
- Coverage:Up to 170 sq. ft.
- Package Size:Two 3.75-pound bags
- Grass Type:St. Augustine
- Additional Feature:Targets bare lawn patches
- Additional Feature:Supports localized repairs
- Additional Feature:Ready-to-use repair mix
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Scotts Turf Builder Lawn Food 12.5 Pounds
This is the practical choice if you want a familiar all-grass lawn food in a package sized for 5,000 square feet. The 12.5-pound bag fits routine feeding plans and can work for St. Augustine when the label confirms the application rate.
Its broad grass compatibility is useful, but the listing does not state an N-P-K formula or identify a St. Augustine-specific blend. That makes it less tailored than the Sunniland products in this roundup.
- Brand:Scotts
- Product Type:Granular lawn fertilizer
- Coverage:5,000 sq. ft.
- Package Size:12.5 pounds
- Grass Type:All grass types
- Additional Feature:Turf Builder lawn food
- Additional Feature:Routine lawn feeding
- Additional Feature:Broad grass compatibility
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Scotts Liquid Green Max 2-in-1
Pick this Scotts liquid feed when green color is your priority and you also want an iron supplement. The 2-in-1 fertilizer and iron formula, 32-ounce container, and all-grass compatibility make it useful for color-focused maintenance across different turf types.
The listing does not specify the N-P-K ratio or coverage, so you cannot judge its nutrient balance from the product name alone. It is best treated as a color-support option, not a fully specified St. Augustine feeding program.
- Brand:Scotts
- Product Type:Liquid fertilizer
- Package Size:32 ounces
- Grass Type:Any grass type
- Additional Feature:Two-in-one fertilizer
- Additional Feature:Includes iron supplement
- Additional Feature:Suitable for lawn maintenance
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Scotts Turf Builder SummerGuard 5,000 Sq. Ft.
This product combines lawn feeding with insect control, making it a fit for summer maintenance when you want one granular application to address both needs. The package covers 5,000 square feet, giving it useful reach for a typical residential lawn.
The combined treatment is also its limitation, since it is not a fertilizer-only product. The listing does not state the N-P-K formula or name the insects controlled, so check the label for turf safety and target-pest details.
- Brand:Scotts
- Product Type:Lawn fertilizer and insect killer
- Coverage:5,000 sq. ft.
- Package Size:13.35 pounds
- Additional Feature:Summer lawn treatment
- Additional Feature:Granular application format
- Additional Feature:Combines feeding and pest control
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SeedRanch St. Augustine Fertilizer 24-2-11
SeedRanch targets St. Augustine lawns with a clearly listed 24-2-11 analysis, including a high nitrogen percentage for growth and color support. The 50-pound bag is suited to homeowners managing larger areas or keeping fertilizer on hand for repeated applications.
That large package can be excessive for a small lawn, and the listing does not provide coverage or application timing. You will need the label rate to determine how much product your yard actually requires.
- Brand:SeedRanch
- Product Type:Granular lawn fertilizer
- N-P-K Formula:24-2-11
- Package Size:50 pounds
- Grass Type:St. Augustine
- Additional Feature:Designed for turf feeding
- Additional Feature:Large-format fertilizer bag
- Additional Feature:Supports St. Augustine lawns
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Pennington Full Season Fertilizer 32-0-5
Pennington’s Full Season formula is aimed at homeowners who prefer a single seasonal application instead of several feeding sessions. Its slow-release fertilizer, 32-0-5 analysis, and 11.2-pound bags make it a strong fit for planned lawn maintenance.
The package format is less straightforward than a standard single bag, and the listing does not state coverage in the available details. You should verify the application schedule and total treated area before applying it to St. Augustine grass.
- Brand:Pennington
- Product Type:Slow-release lawn fertilizer
- N-P-K Formula:32-0-5
- Package Size:Three 11.2-pound bags
- Grass Type:Grass
- Additional Feature:Full-season feeding plan
- Additional Feature:Supports lawn growth
- Additional Feature:Promotes lawn greening
Frequently Asked Questions
What N-P-K ratio is best for St Augustine grass?
There is no single ideal ratio for every lawn because soil type, climate, mowing practices, and nutrient levels vary. A formula with moderate nitrogen, limited phosphorus, and useful potassium is a sensible starting point for established turf. Use a soil test to refine the choice, especially if your grass has persistent yellowing or weak growth. Apply the label rate, since extra fertilizer will not correct problems caused by poor drainage, pests, or disease.
How often should you fertilize St Augustine grass?
Feed St Augustine during its active growing season, following the schedule on the product label and local lawn-care recommendations. Many lawns need several light applications rather than one heavy dose. Stop or reduce feeding during winter dormancy, extreme heat, or drought stress. Fertilizing stressed grass can increase damage instead of improving color.
Can you use weed-and-feed on St Augustine grass?
You can use one only if the label specifically lists St Augustine grass and the target weeds. Some herbicides used in weed-and-feed products can cause serious injury to St Augustine, especially when applied in hot weather. Apply only within the stated temperature range, and avoid treating a lawn that is drought-stressed or dormant. A separate fertilizer and carefully selected herbicide often gives you better control over timing and dosage.
Should you choose granular or liquid fertilizer?
Granular fertilizer usually offers longer feeding and is easy to store, making it a practical choice for routine lawn care. You need a calibrated spreader and even coverage to prevent striping or burn. Liquid fertilizer works quickly and distributes evenly when mixed correctly, but it often requires more frequent applications. It can be useful for correcting visible deficiency, although you must measure the concentrate carefully.
Is fertilizer safe for pets and children?
Keep people and pets off the lawn during application and for the reentry period on the label. Store fertilizer in its original container, away from food, moisture, children, and animals. Water the lawn as directed after applying granular products, then allow the surface to dry before normal use if the label permits. Sweep stray granules from sidewalks and patios so they are not tracked indoors or washed into drains.
