You are kneeling on the grass, holding a spreader that feels a bit too heavy, and you are staring at a patchy, yellowish lawn that simply refuses to cooperate. It is frustrating to watch your neighbor's yard stay lush and deep green while yours looks like it gave up weeks ago.
Getting your lawn back on track is a matter of science rather than luck. By selecting the Best Fertilizers for St. Augustine Grass, you provide the exact nutrients your turf needs to spread and thrive. Let us review the options that will help you achieve that thick, emerald carpet you want.
Key Takeaways
- Prioritize formulas that specify a slow-release nitrogen content to prevent grass from burning during the peak heat of summer.
- Check the NPK ratio on the label, as warm-season grasses like St. Augustine often thrive with higher nitrogen levels and lower phosphorus content.
- Consider whether your lawn requires a dual-action product that handles weed control alongside fertilization to save time on maintenance.
- Opt for liquid applications if you need fast nutrient delivery to correct a yellowing lawn, while granular options are superior for long-term feeding.
- Always match the square footage of your lawn to the bag size, as using the incorrect amount can lead to over-application or inadequate coverage.
| Best All-Around Choice |  |
Sunniland St. Augustine Weed and Feed | Combines feeding and weeding | Simple single step application | Targeted for St. Augustine | View on Amazon | Read Review |
| Rapid Nutrient Delivery |  |
Simple Lawn Solutions Balanced Liquid Fertilizer | Rapid nutrient absorption | Easy to apply spray | Balanced NPK ratio | View on Amazon | Read Review |
| Best Growth Stimulator |  |
St. Augustine Liquid Lawn Food | Promotes runners and spread | Encourages deep green color | Supports root development | View on Amazon | Read Review |
| Phosphorus Free Choice |  |
Sunniland St. Augustine Granular Fertilizer | Phosphorus free | Slow release nitrogen | Long lasting nutrition | View on Amazon | Read Review |
| Best Iron Supplement |  |
Scotts Green Max Lawn Food | Added iron for color | Quick greening results | Proven fertilizer brand | View on Amazon | Read Review |
| Reliable General Maintenance |  |
Scotts Turf Builder Lawn Food | Builds strong roots | Consistent growth performance | Simple application process | View on Amazon | Read Review |
| Heavy Weed Defense |  |
Scotts Turf Builder Weed and Feed | Kills common lawn weeds | Feeds for thicker grass | Covers large areas | View on Amazon | Read Review |
| Best Pest Protection |  |
Scotts SummerGuard Lawn Food | Includes insect killer | Prevents summer damage | Dual purpose fertilizer | View on Amazon | Read Review |
| Best Soil Conditioner |  |
Andersons Professional PGF Complete | Contains humic acid | Professional grade fertilizer | Small granule size | View on Amazon | Read Review |
| Best Slow Release |  |
Fertilome Slow Release 15-0-15 | Slow release technology | High iron content | Lasting nutrient supply | View on Amazon | Read Review |
More Details on Our Top Picks
-
Sunniland St. Augustine Weed and Feed
Managing weeds while feeding your grass is like killing two birds with one stone. This product is the gold standard for St. Augustine owners who need a comprehensive solution to maintain a healthy, uniform lawn without juggling multiple bags of chemicals.
It works exceptionally well for lawns that are already established and just need a little extra muscle to fight off invasive weeds. Just keep in mind that since it contains a herbicide, you should be careful not to apply it near your prized flower beds or ornamental shrubs.
- Brand:Sunniland
- Coverage:5000 sq ft
- Function:Weed and feed
- Additional Feature:Controls common lawn weeds
- Additional Feature:Sustained nitrogen release
- Additional Feature:Promotes dense turf growth
-
Simple Lawn Solutions Balanced Liquid Fertilizer
If your lawn looks a bit tired, a liquid spray is the quickest way to inject energy back into the soil. The 16-4-8 formula acts as a concentrated growth booster that your grass absorbs almost immediately through its leaves and roots.
This is perfect for a quick spring refresh or a mid-summer pick-me-up. Because it is a liquid, you will need to spray it more often than a granular product to maintain those lush green results.
- Brand:Simple Lawn Solutions
- Type:Liquid
- Formula:16-4-8
- Function:Growth booster
- Additional Feature:Concentrated formula
- Additional Feature:Suitable for all grass
- Additional Feature:High bioavailability
-
St. Augustine Liquid Lawn Food
Focusing on thicker growth, this liquid formula is designed to help your St. Augustine spread its runners efficiently. It is a fantastic choice if you have bare spots you want to fill in or if you just want a denser, healthier carpet of grass.
You will appreciate how easy it is to mix and feed, making it a low-stress option for weekend maintenance. Do not expect it to last as long as a granular slow-release product, however, as it is designed for frequent, light feedings.
- Brand:Generic
- Type:Liquid
- Weight:8 oz
- Function:Growth and color
- Additional Feature:High nitrogen formula
- Additional Feature:Fast nutrient delivery
- Additional Feature:Simple mixing instructions
-
Sunniland St. Augustine Granular Fertilizer
Many lawns do not actually need extra phosphorus, and this phosphorus-free formula is a smart way to fertilize without running off into the water supply. It relies on slow-release nitrogen to provide a steady diet for your grass over several weeks.
This approach prevents that annoying growth spike that leads to constant mowing. It is a heavy-duty option that comes in a convenient two-pack for larger lawns.
- Brand:Sunniland
- Formula:20-0-6
- Coverage:10000 sq ft
- Weight:40 lbs total
- Additional Feature:Granular texture
- Additional Feature:Steady growth rate
- Additional Feature:Environmentally conscious formula
-
Scotts Green Max Lawn Food
When your grass is thin or pale, iron is often the missing link you need to get that deep, dark green color back. This fertilizer delivers a dual-action punch by feeding the grass and supplementing the soil with essential iron.
It is particularly effective if you live in an area with high pH soil where iron is hard for grass to reach. Just remember that iron can leave rust-colored stains on your driveway or sidewalk, so sweep those surfaces off promptly after application.
- Brand:Scotts
- Coverage:5000 sq ft
- Weight:16.67 lbs
- Function:Greening and feed
- Additional Feature:Dual action formula
- Additional Feature:Deep green results
- Additional Feature:Fast acting ingredients
-
Scotts Turf Builder Lawn Food
Sometimes you just need a no-nonsense fertilizer that does exactly what the bag says it will do. This is a classic choice for year-round maintenance that helps your grass build a strong root system while thickening up the blades.
It is essentially the workhorse of the lawn care world. While it lacks specialty weed killers or insect control, it is a dependable staple for keeping your yard consistent throughout the growing season.
- Brand:Scotts
- Coverage:5000 sq ft
- Weight:12.5 lbs
- Function:General feeding
- Additional Feature:All grass types
- Additional Feature:Turf building strength
- Additional Feature:Standardized nutrient balance
-
Scotts Turf Builder Weed and Feed
If your lawn is being overrun by clover and dandelions, you need a product that fights back. This formula acts as both a weed killer and a fertilizer, which makes it a great choice for a spring cleanup session.
It targets those pesky invaders while giving your St. Augustine the boost it needs to choke them out. Be mindful that this is a strong chemical product, so it is best to use it when the weather is mild and wind is low.
- Brand:Scotts
- Coverage:5000 sq ft
- Weight:14.29 lbs
- Function:Weed and feed
- Additional Feature:Controls clover
- Additional Feature:Dandelion reduction
- Additional Feature:Scotts delivery system
-
Scotts SummerGuard Lawn Food
Summer is the time when bugs like chinch bugs can wreak havoc on your St. Augustine. This product is a dual-threat that feeds your lawn and provides insect control to keep your grass safe during the hot months.
It is a proactive way to handle two problems at once, saving you from having to apply a separate insecticide later. Just make sure you follow the watering instructions closely to ensure the granules work their way into the soil effectively.
- Brand:Scotts
- Coverage:5000 sq ft
- Weight:13.35 lbs
- Function:Feed and pest control
- Additional Feature:Protects against insects
- Additional Feature:Summer heat defense
- Additional Feature:Simple granule spreader
-
Andersons Professional PGF Complete
This fertilizer includes humic acid, which acts like a vitamin supplement for your soil. By improving the soil structure, it helps your grass take up the 16-4-8 nutrients much more efficiently than a standard fertilizer would.
It is a professional-grade product that delivers consistent, high-quality results for homeowners who take their lawn seriously. The granules are very small, which helps them reach the soil surface and disappear quickly after watering.
- Brand:The Andersons
- Formula:16-4-8
- Coverage:5000 sq ft
- Function:Soil conditioning
- Additional Feature:7% humic DG
- Additional Feature:Enhanced root uptake
- Additional Feature:Professional quality
-
Fertilome Slow Release 15-0-15
When you want a steady supply of nutrients, a slow-release formula is your best friend. This 15-0-15 blend ensures your grass isn't hit with a massive growth spurt that requires constant mowing, but rather receives a consistent, gentle feeding over time.
The high iron content is a great bonus for maintaining a deep, dark color. It is an ideal choice for the budget-conscious homeowner who wants to spend less time in the yard and more time relaxing.
- Brand:Fertilome
- Formula:15-0-15
- Weight:16 lbs
- Function:Slow release feed
- Additional Feature:Balanced nutrient ratio
- Additional Feature:Warm season grass focus
- Additional Feature:High iron boost
Frequently Asked Questions
How often should I fertilize my St. Augustine grass?
Most experts recommend applying fertilizer four times a year during the peak growing season. Start your first round in the spring after the grass has fully greened up and the danger of frost has passed.
Can I fertilize if the temperature is over 90 degrees?
You should generally avoid fertilizing when the temperature consistently stays above 90 degrees Fahrenheit. Applying nitrogen during extreme heat can stress the root system and potentially burn your lawn.
Why is my grass turning yellow even after I fertilize?
Yellowing often points to an iron deficiency or an incorrect soil pH. If your soil is too alkaline, the grass cannot absorb nutrients properly, which makes adding iron or sulfur necessary to correct the balance.
Should I water after applying fertilizer?
Yes, watering is essential to help the nutrients move into the soil and reach the roots. A light watering of about one-quarter inch is usually sufficient to wash the granules off the blades and into the dirt.
Is it better to use liquid or granular fertilizer?
Granular fertilizer is usually the better choice for the average homeowner because it typically contains slow-release components that last longer. Liquid fertilizers work faster but require more frequent applications to keep the lawn healthy throughout the season.
