Finding the right fertilizer for St. Augustine grass can help restore a rich green color and strong growth, especially when yellowing patches appear. This guide reviews five well-regarded options available on Amazon, highlighting how each product targets St. Augustine lawns, weed control, and nutrient delivery. You’ll see practical details on application, release type, and soil compatibility, plus a concise buying guide to help you compare feed types, timing, and safety considerations. Use the summary table below to quickly compare core features before diving into full product insights.
| Product | Brand | Key Benefit |
|---|---|---|
| Fertilome (13915) St. Augustine Weed & Feed 15-0-4 | Ferti-Lome | Weed control plus fertilizer for St. Augustine lawns |
| LESCO 50 lb. St. Augustine Grass Weed and Feed with Penoxsulam | LESCO | Professional-grade weed and feed with slow release |
| Scotts Turf Builder Lawn Food | Scotts | All-grass formula for strong roots and water/nutrient uptake |
| Sunniland Weed & Feed 20-0-6 | Generic | Balanced weed control with high phosphorus-free formula |
| SeedRanch St. Augustine Lawn 24-2-11 | Lesco | Higher-nitrogen feed with iron greening |
Note: This review focuses on products suitable for St. Augustine grass, including options that blend fertilization with weed control. Always follow label directions and consider soil testing to tailor nutrient needs for your specific lawn conditions.
Fertilome (13915) St. Augustine Weed & Feed 15-0-4
Overview: This product combines herbicidal action with a 15-0-4 fertilizer mix designed for St. Augustine lawns. It targets both pre-emergent and post-emergent weeds while delivering essential nutrients to promote growth and color recovery. The formulation is described as suitable for Centipede, Zoysia, and St. Augustine grasses, but not Bermuda or other Northern grass varieties.
Key Features: The 15-0-4 ratio emphasizes phosphorus and potassium relative to nitrogen, supporting root development and stress tolerance. The product’s weed-control component helps manage broadleaf and grassy weeds present in warm-season lawns. Application timing typically aligns with weed development stages and local climate windows. For best results, apply to actively growing turf, and avoid applying during extreme heat. The product is labeled specifically for St. Augustine types, with cautions for incompatible grasses.
Application Considerations: Follow the product’s application rate to minimize leaf burn and ensure even coverage. Watering after application can help with nutrient uptake and weed control efficacy. If you have Floratam or other St. Augustine varieties, verify compatibility and consider patch-testing on a small area before broad use. This product can be a practical option when weed pressure and nutrient needs coincide, particularly in late spring or early fall.
Strengths: Integrated weed control plus targeted feed; simple, single-step approach; specifically marketed toward St. Augustine and similar warm-season lawns. Limitations: Not suitable for Bermuda; may not deliver rapid green-up in severe yellowing without adequate soil moisture and ongoing maintenance.
LESCO 50 lb. St. Augustine Grass Weed and Feed with Penoxsulam
Overview: This professional-grade product is designed for larger lawns and commercial-type applications, featuring a 50 lb bag and the herbicide penoxsulam alongside a specially blended fertilizer. It emphasizes St. Augustine turf and offers a slow-release strategy intended to sustain feeding for up to eight weeks.
Key Features: The formulation includes 13-0-0? Wait, the listing specifies 17-0-17 with additional sulfur-coated urea for slow release. It is designed to be applied when the turf is wet, then allowed to dry for visible results in about two weeks. It is labeled as safe for Floratam varieties, with slow-release characteristics that promote extended feeding. The product is positioned as a comprehensive weed-and-feed solution tailored to St. Augustine grass, with a focus on durable feeding and weed suppression over time.
Application Considerations: Apply with adequate moisture and avoid heavy irrigation immediately after application if the label instructs otherwise. For Floratam and similar varieties, confirm compatibility with your specific cultivar. This product is best suited for lawns where weed pressure is persistent and where a longer feeding cycle is desirable, balancing growth and weed control across the season.
Strengths: Professional-grade formulation; slow-release nutrients support extended feeding; effective for Floratam and other St. Augustine varieties. Limitations: The bag size and application rate may require careful planning for smaller lawns; always follow label directions for watering and application timing.
Scotts Turf Builder Lawn Food
Overview: Scotts Turf Builder Lawn Food is a versatile fertilizer designed to feed all grass types, with a focus on fostering deep, robust root systems and improved nutrient uptake. It is often marketed for general lawn health, including St. Augustine lawns, and supports a proactive defense against common lawn problems.
Key Features: The product claims to build strong, deep roots and enhance the lawn’s absorption of water and nutrients compared to unfed lawns. It is designed for both wet and dry applications, offering flexibility for different weather conditions. The all-grass approach makes it a convenient option for households with multiple lawn varieties or for homeowners who want a single product for mixed turf features.
Application Considerations: Apply according to soil conditions and lawn size, with attention to watering guidelines after application. In hot climates or drought periods, choose timing that aligns with cooler periods or increased irrigation to maximize effectiveness. For St. Augustine lawns, ensure consistent moisture and monitor for signs of nutrient deficiency or weed pressure that may require additional, targeted treatments.
Strengths: Broad compatibility with most grass types; supports root development and nutrient uptake; flexible application. Limitations: Not specifically formulated for weed control in St. Augustine lawns; may require a separate weed-control strategy to address broadleaf and grassy weeds.
Sunniland Weed & Feed 20-0-6
Overview: Sunniland Weed & Feed 20-0-6 is designed to simplify lawn care with a weed-control component and a balanced fertilizer ratio suitable for St. Augustine grasses. The product emphasizes easy spreading and handling, with a plan that typically involves two applications in spring and fall.
Key Features: The 20-0-6 nutrient blend emphasizes nitrogen for green-up while keeping phosphorus low, which can be advantageous for lawns where phosphorus runoff is a concern. The product mentions compatibility with all St. Augustine grass types, offering a broad-use approach for warm-season lawns. The dual-action formula targets broadleaf and some grassy weeds while providing gentle, ongoing feed.
Application Considerations: Follow recommended rates and ensure even distribution to prevent streaking. Watering after application may improve nutrient availability and weed suppression efficacy. In regions with heavy weed pressure or nutrient-poor soils, consider pairing with a soil test to tailor subsequent feeds.
Strengths: Convenience of weed control paired with fertilizer; user-friendly for spring and fall schedules. Limitations: Lower phosphorus content means limited phosphorous-driven root development; may be less effective for heavy weed burdens without complementary treatments.
Scotts Turf Builder Southern Lawn Fertilizer
Overview: This Scotts formula targets southern grasses, focusing on heat and drought resilience. The product is designed to build strong roots with a take-all approach to stress tolerance, aiming to sustain growth through challenging summer conditions typical of Southern lawns.
Key Features: The blend includes all-in-one particles that deliver comprehensive feeding and root-support. It emphasizes robustness against heat stress and drought, helping lawns to maintain color and density during periods of lower rainfall. The product highlights compatibility with Southern turf varieties and adaptable application for wet or dry conditions.
Application Considerations: Apply during the growing season when temperatures are manageable and soil moisture supports uptake. For St. Augustine lawns, ensure the product does not overly boost phosphorus or other nutrients if soil tests indicate specific deficiencies or excesses. Pair with proper irrigation to optimize results and prevent nutrient burn in sunny climates.
Strengths: Tailored for Southern climates; deep root development supports drought resilience; straightforward application. Limitations: Not single-granule weed control; best used as a general lawn feeder with supplemental weed management as needed.
SeedRanch St. Augustine Lawn 24-2-11 Fertilizer
Overview: This Lesco-branded product is a high-nitrogen fertilizer tailored for St. Augustine lawns, offering a 24-2-11 nutrient ratio with added iron. The formulation aims to promote vigorous greens and deeper color while supporting root development and overall lawn health.
Key Features: The 24-2-11 blend emphasizes nitrogen for quick greening and growth, with 11% potassium supporting stress tolerance. The product notes 12,000 square feet coverage, making it suitable for mid-size to larger residential lawns. The inclusion of iron is highlighted as enhancing greening and color intensity, a common request for yellowing or pale lawns.
Application Considerations: Align applications with active growing seasons and soil moisture conditions. Iron-containing feeds can sometimes cause temporary staining on sidewalks or driveways if misapplied, so apply carefully and water after spreading. For St. Augustine varieties, ensure compatibility with your specific cultivar and observe label directions for cooling or hot-season adjustments.
Strengths: Strong greening effect via iron; clear nitrogen emphasis for fast response; sizable coverage area. Limitations: Higher nitrogen content requires mindful timing to avoid leaf burn during heat or drought; may require additional weed management separately.
Organic Plant Magic Truly Organic Lawn Fertilizer
Overview: Organic Plant Magic offers a fully organic, slow-release granular lawn fertilizer intended for multiple grass types, including St. Augustine and Bermuda. The product emphasizes GroBiotics with amino and humic acids to support soil biology and plant nutrition from an organic perspective.
Key Features: The formulation is marketed as safe for kids, pets, and the environment, aligning with non-toxic organic practices. It highlights its all-natural approach with beneficial biology components and a focus on “ABC’s of Organic Growing.” The product aims to provide steady nutrition while promoting soil health and microbial activity that can improve nutrient uptake over time.
Application Considerations: Organic products typically require longer-term feeding and consistent soil moisture for best results. For St. Augustine lawns with yellowing patches, expect gradual greening with regular applications rather than immediate color change. This product appeals to those prioritizing organic lawn care and environmental stewardship.
Strengths: Strong organic positioning; soil-biome friendly; slow-release design supports steady growth. Limitations: Slower immediate greening compared to synthetic blends; effectiveness depends on soil biology and moisture conditions.
Buying Guide: Key Purchase Considerations
- Grass Type and Climate: Confirm the product is suitable for St. Augustine lawns and your local climate. Some blends are tailored for Floratam or other St. Augustine varieties, while others are universal for warm-season grasses.
- Nitrogen Form and Release: Fast-release nitrogen provides quicker green-up, while slow-release nutrients extend feeding periods and reduce burn risk. For yellowing lawns, fast-acting feeds can provide quick relief, but slow-release feeds help sustain color during stress periods.
- Weed Control vs. Pure Fertilization: If weed pressure is high, consider a weed-and-feed product. If weed pressure is low, a topical fertilizer alone may suffice, enabling more precise nutrient management.
- Phosphorus and Potassium Balance: Some regions regulate phosphorus; choosing a fertilizer with appropriate P and K can support root growth and drought tolerance without overloading the lawn with phosphorus.
- Iron Content: Iron supplements can enhance greening, but excessive iron can cause staining or imbalances. Iron is especially helpful for pale or yellowing lawns, but use as directed.
- Application Timing: Align feeding with the lawn’s growth cycle and local seasonality. Spring and fall are common windows for warm-season grasses, with lighter, more frequent applications during peak growth periods.
- Soil Testing: A soil test informs nutrient needs and helps tailor fertilizer choices. This can prevent over-fertilization and ensure balanced plant nutrition.
- Safety and Environmental Considerations: Follow label directions, avoid runoff into waterways, and use protective gear during application. Organic options may reduce environmental impact but still require careful usage.
In summary, the best choice for yellowing St. Augustine lawns depends on your priorities: rapid greening with weed suppression (Fertilome or Sunniland options), professional-grade weed and feed with long-lasting effects (LESCO), or a household-friendly all-purpose option (Scotts Turf Builder). For those prioritizing organics, Organic Plant Magic provides a compliant, eco-friendly approach, while SeedRanch offers a high-nitrogen strategy with iron for enhanced greening.
Whichever product you select, consistency is key. Regular applications aligned with seasonal growth and soil moisture will help maintain a healthy, vibrant St. Augustine lawn, reducing the likelihood of persistent yellowing and weed encroachment.