St. Augustine grass is a demanding host. It craves specific nutrients and reacts poorly to harsh chemicals that other grasses tolerate with ease. Identifying the Best Fertilizers for St. Augustine Grass requires a focus on soil chemistry and timing rather than just mass-market popularity.
Feeding your lawn is like balancing a delicate scale. Too much nitrogen can burn the blades, yet neglect turns a lush carpet into a patch of brown straw. Use this guide to choose the right strategy for your soil health.
Key Takeaways
- Prioritize formulas that specify low or zero phosphorus to prevent unnecessary environmental runoff.
- Verify that any weed control ingredients are explicitly labeled as safe for warm-season grasses to avoid killing your lawn.
- Opt for slow-release nitrogen sources to ensure your grass gets a steady meal instead of an exhausting growth spurt.
- Select liquid formulas for rapid absorption if you need to correct yellowing or iron deficiencies immediately.
- Choose granular options for long-term maintenance and building thicker, more resilient turf density over several months.
| Best Overall Maintenance |  |
Sunniland St. Augustine Weed and Feed | Combines feeding and weeding | Specifically for St. Augustine | Easy to spread granules | View on Amazon | Read Review |
| Rapid Growth Booster |  |
Liquid St. Augustine Lawn Food | Promotes dense growth | Encourages new runners | Fast nutrient absorption | View on Amazon | Read Review |
| Reliable Slow Release |  |
Sunniland 20-0-6 St. Augustine Fertilizer | Sustained nitrogen release | No added phosphorus | Professional grade results | View on Amazon | Read Review |
| Balanced Iron Supplement |  |
Fertilome 15-0-15 Centipede and St. Augustine | High iron content | Balanced nutrient ratio | Boosts stress tolerance | View on Amazon | Read Review |
| Versatile Seasonal Feed |  |
Advanced 16-4-8 Liquid Fertilizer | Balanced nutrient blend | Concentrated liquid formula | Works on any grass | View on Amazon | Read Review |
| Color Enhancement Expert |  |
Scotts Green Max Iron Fertilizer | Rapid greening results | Added iron supplement | Visible improvement quickly | View on Amazon | Read Review |
| Universal Turf Foundation |  |
Scotts Turf Builder Lawn Food | Builds root strength | Improves water intake | Reliable brand quality | View on Amazon | Read Review |
| High Performance Feeding |  |
SeedRanch St. Augustine 24-2-11 Fertilizer | Bulk volume for large areas | High nitrogen content | Encourages thick density | View on Amazon | Read Review |
| Persistent Weed Control |  |
Fertilome St. Augustine Weed and Feed | Contains Atrazine herbicide | Kills existing weeds | Prevents future growth | View on Amazon | Read Review |
| Small Spot Specialist |  |
Scotts EZ Patch Lawn Repair | Repairs small bare spots | Includes mulch for moisture | Simple spot treatment | View on Amazon | Read Review |
More Details on Our Top Picks
-
Sunniland St. Augustine Weed and Feed
This is the go-to choice if your primary goal is tackling weeds while feeding your turf. It acts as a dual-action powerhouse that cleans up your lawn’s appearance in one pass.
The granule formula is designed specifically for the needs of St. Augustine grass. Keep in mind that you need to watch your application timing to ensure the weeds are actively growing for the best results.
- Brand:Sunniland
- Target Coverage:5,000 sq ft
- Additional Feature:Kills common lawn weeds
- Additional Feature:Sustains turf health
- Additional Feature:Standard granular application
-
Liquid St. Augustine Lawn Food
Liquid formulas are the equivalent of a quick espresso shot for your soil. If you want to see your grass runners fill in bare patches, this spray provides the nutrients in a highly accessible form.
Because it absorbs quickly, you will notice a rich green color much faster than with slow-release granular options. Just remember that liquids require more frequent applications to keep the momentum going throughout the season.
- Weight Or Volume:1 Gallon
- Application Type:Liquid spray
- Additional Feature:Deepens grass color
- Additional Feature:Supports root development
- Additional Feature:Easy to apply via hose
-
Sunniland 20-0-6 St. Augustine Fertilizer
When you want consistent, long-term growth without the risk of burning your lawn, this slow-release nitrogen formula is your best friend. It provides a steady diet of nutrients that keeps your grass looking sharp for weeks at a time.
Since this mix is phosphorus-free, it is a responsible choice for areas with strict runoff regulations. It is a solid, no-nonsense feed for homeowners who prefer a set-it-and-forget-it approach to lawn care.
- Brand:Sunniland
- Formulation:20-0-6
- Weight Or Volume:40 lbs total
- Target Coverage:10,000 sq ft
- Additional Feature:Granular texture
- Additional Feature:Prevents nutrient spikes
- Additional Feature:Two bag value pack
-
Fertilome 15-0-15 Centipede and St. Augustine
This formula is excellent for correcting deficiencies that cause yellowing or weak blades. The high iron content serves as a color-enhancing catalyst, giving your lawn a deep, healthy emerald hue.
Its 15-0-15 balance ensures your grass gets enough potassium to build strength against environmental stress. It is a great pick if your lawn feels a bit tired or lacks the vibrant color you expect from healthy St. Augustine.
- Brand:Fertilome
- Formulation:15-0-15
- Weight Or Volume:16 lbs
- Added Nutrients:Iron
- Additional Feature:Slow release nitrogen
- Additional Feature:Safe for warm-season grasses
- Additional Feature:Corrects yellowing blades
-
Advanced 16-4-8 Liquid Fertilizer
If you manage different grass types or just want a versatile liquid solution, this balanced NPK formula handles the job well. It is highly concentrated, making it simple to spray across your lawn during the peak spring and summer months.
The formula provides a well-rounded nutritional profile that supports both leaf growth and root health. Because it is a liquid, you can target specific areas that need extra attention without spreading material where it is not wanted.
- Brand:Simple Lawn Solutions
- Formulation:16-4-8
- Weight Or Volume:32 Ounce
- Application Type:Liquid spray
- Additional Feature:Easy to mix
- Additional Feature:Good for summer growth
- Additional Feature:Highly concentrated bottle
-
Scotts Green Max Iron Fertilizer
Sometimes your grass is healthy but simply lacks that deep, dark green look. This iron-rich product acts like a fresh coat of paint for your turf, providing a visible difference in just a few days.
It is a great choice if you have an upcoming event and want your yard to look its absolute best. Keep in mind that this is primarily a color supplement, so it works best when used alongside a regular feeding program.
- Brand:Scotts
- Weight Or Volume:16.67 lbs
- Target Coverage:5,000 sq ft
- Added Nutrients:Iron
- Additional Feature:Non-staining formula
- Additional Feature:Rapid absorption
- Additional Feature:Improves overall lawn aesthetic
-
Scotts Turf Builder Lawn Food
This is the classic staple for homeowners who want a predictable, reliable feed for their yard. It is formulated to strengthen your grass against the typical pressures of heat and drought, which is a major concern for St. Augustine owners.
The granules are designed to improve water absorption, helping your lawn stay hydrated even in the middle of summer. It is a straightforward product that provides exactly what the label promises without unnecessary complications.
- Brand:Scotts
- Weight Or Volume:12.5 lbs
- Target Coverage:5,000 sq ft
- Additional Feature:Heat stress protection
- Additional Feature:Standard granular application
- Additional Feature:Easy to spread
-
SeedRanch St. Augustine 24-2-11 Fertilizer
When you have a large property to cover, you need a high-output fertilizer that delivers a heavy dose of nutrients. This bag provides a significant amount of material to ensure your lawn has everything it needs for aggressive growth.
The 24-2-11 ratio is perfect for maintaining the thick, lush carpet that St. Augustine is known for. Because it is sold in bulk, it is the most efficient choice for maintaining expansive lawns throughout the growing season.
- Brand:SeedRanch
- Formulation:24-2-11
- Weight Or Volume:50 lbs
- Additional Feature:Professional style ratio
- Additional Feature:Sustains large lawns
- Additional Feature:Strong nutrient profile
-
Fertilome St. Augustine Weed and Feed
Weeds often sneak into St. Augustine lawns, but this granular product includes Atrazine for effective control. It acts as both a pre-emergent and post-emergent shield, stopping weeds in their tracks before they take over.
The 15-0-4 formula provides a consistent nutritional base while the herbicide does the heavy lifting against broadleaf invaders. It is a smart pick if you struggle with invasive plants and need a solution that remains safe for your grass.
- Brand:Fertilome
- Formulation:15-0-4
- Weight Or Volume:25.6 lbs
- Added Nutrients:Atrazine
- Additional Feature:Granular weed control
- Additional Feature:Safe for warm-season grass
- Additional Feature:Pre-emergent protection
-
Scotts EZ Patch Lawn Repair
Every lawn ends up with a few bare spots from pet traffic or heavy shade. This repair mix combines fertilizer, mulch, and seed-bed preparation into a single product to help those spots recover quickly.
It is like a first-aid kit for your grass, designed to fix small areas rather than feed the entire yard. The mulch helps keep moisture near the soil, which is vital for helping St. Augustine runners re-establish themselves.
- Brand:Scotts
- Application Type:Patch mix
- Target Coverage:170 sq ft
- Additional Feature:Fast moisture retention
- Additional Feature:Convenient two pack
- Additional Feature:Targeted application method
Frequently Asked Questions
How often should I fertilize my St. Augustine lawn?
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. Stop all fertilization about six weeks before your area’s first expected frost.
Will fertilizer kill my grass if I apply too much?
Yes, excessive application often leads to nitrogen burn, which turns grass blades brown and brittle. Always follow the spreader settings listed on the bag to ensure an even distribution. If you accidentally spill a pile, scoop it up immediately and rinse the area thoroughly with water.
Should I water after applying fertilizer?
Watering is essential to push the granules down into the soil where the roots can actually reach them. Lightly irrigate your lawn with about a quarter inch of water shortly after application. This helps prevent the fertilizer from sitting on the blades, which reduces the risk of leaf scorch.
Can I use a weed and feed product on my lawn?
You can, but you must be careful because many generic weed killers are toxic to St. Augustine. Only use products explicitly labeled for this grass variety. If you have a severe weed problem, it is often safer to apply a separate fertilizer and a targeted spot-treatment herbicide.
Why is my grass still pale after fertilizing?
A pale lawn is often a sign of poor nutrient uptake caused by high soil pH or compacted ground. If the fertilizer has not worked after three weeks, consider performing a soil test to check your pH levels. You might need to adjust the acidity before the roots can access the nutrients you have provided.
