Best Fertilizer For Yellow St Augustine Grass: 10 Options Compared

#1 · Best Overall

1. Sunniland St. Augustine Fertilizer

• Weight: 20 lb
• Form: Granules

Best for: St. Augustine slow-feed granules.

Why it ranks #1: Made for St. Augustine, its 20-0-6 formula supplies nitrogen and potassium, with 50% slow-release nitrogen and no added phosphorus.

A St. Augustine-specific 20-0-6 formula with 50% slow-release nitrogen provides steady feeding for lawns while supplying potassium and omitting added phosphorus. The two-bag pack covers up to 5,000 square feet per bag, giving homeowners a clear coverage reference for planning applications across their turf.

The 20-0-6 ratio pairs nitrogen for turf growth with potassium for lawn health, while the phosphorus-free formula suits buyers seeking those nutrients without added phosphorus. With half the nitrogen slow release, feeding is spread over time rather than delivered all at once. Its granular form calls for lawn-spreading application, and the two 20-pound bags offer a practical supply for the stated 5,000-square-foot coverage per bag; the supplied details do not specify application timing or method.

Skip it if you want a liquid application; TPS Nutrients St Augustine Grass Fertilizer is a listed liquid option.

Choose this pack if you want St. Augustine-focused granular feeding, phosphorus-free 20-0-6 nutrition, and stated coverage for planning. It suits lawns where spreading granules works for your routine; application instructions are not included in the supplied details.

Listed on Amazon as: Sunniland St. Augustine Lawn Fertilizer 20-0-6 – Slow Release Nitrogen Granular Lawn Food – Covers 5,000 sq ft per Bag – Phosphorus Free Turf Fertilizer – 20 lb Bags (2 Pack)

#2 · Iron for Greening

2. Lesco St. Augustine Fertilizer

• Weight: 50 lb
• Form: Granules

Best for: Iron-rich professional St. Augustine feed.

Why it ranks #2: Specifically intended for St. Augustine and includes 6% iron; the 24-2-11 granular formula covers 12,000 square feet.

Six percent iron is the key differentiator in this professional-grade 24-2-11 granular fertilizer, supporting greening of southern lawns when temperatures are cool. Its 12,000-square-foot coverage and St. Augustine focus make it a substantial spring option for homeowners seeking to jump-start turf greening with a single fertilizer blend.

The 24-2-11 nutrient ratio supplies the fertilizer blend, while 6% iron is specifically highlighted for greening. The description recommends spring use to jump-start turf, particularly when outside temperatures are cool, giving buyers a seasonal role for the product. A 50-pound granular bag covers 12,000 square feet, which helps with application planning across larger lawns. Handling guidance calls for gloves and protective clothing, and application should be avoided in hot weather.

Skip it if you need a liquid feed or warm-weather application; TPS Nutrients St Augustine Grass Fertilizer is a listed liquid alternative.

This suits buyers feeding a larger St. Augustine lawn in spring, especially when cool-weather greening is the goal. Its 50-pound granular format and hot-weather restriction make season and handling conditions important considerations.

Listed on Amazon as: SeedRanch St. Augustine Lawn 24-2-11 Fertilizer – 50 Lbs.

#3 · Potassium-Rich Formula

3. Lawn Synergy Emerald Fertilizer

• Weight: 18 lb
• Form: Granules

Best for: Potassium-rich St. Augustine stress support.

Why it ranks #3: Lists St. Augustine among compatible grasses and combines 10-0-20 nutrition, iron, micronutrients, and 45% slow-release nitrogen.

A 10-0-20 formula combines high potassium with iron and micronutrients to support dark green color without pushing top growth. Listed for St. Augustine as well as several other grasses, this 18-pound granular fertilizer pairs 45% slow-release nitrogen with steady feeding for up to eight weeks.

The high-potassium 10-0-20 blend is presented for drought tolerance, disease resistance, and root strength, connecting its nutrient emphasis to lawn durability. Iron and Nutrace micronutrients support a dark green appearance without excess top growth. With 45% slow-release nitrogen and feeding described for up to eight weeks, the granules offer gradual nutrition rather than a single quick burst. St. Augustine is explicitly listed among compatible grasses; the supplied details advise following application instructions but do not state coverage.

Skip it if you require a stated coverage area; Sunniland St. Augustine Lawn Fertilizer gives coverage of 5,000 square feet per bag.

This suits St. Augustine owners seeking potassium-rich support, gradual feeding, and color without excess top growth. Its granular format and unstated coverage mean buyers should be comfortable planning application from the package directions.

Listed on Amazon as: 10-0-20 Emerald Lawn Fertilizer 18lbs – Slow-Release Nitrogen, Iron, & Micronutrients – Dark Green Lawn for Tall Fescue, St. Augustine, Zoysia, Centipede

#4 · Fertilizer Plus Weed Control

4. Ferti-lome St. Augustine Weed & Feed

• Weight: 12.8 lb
• Form: Granules

Best for: St. Augustine weed-and-feed granules.

Why it ranks #4: Designed for St. Augustine and provides 15-0-4 fertilizer alongside pre- and post-emergent weed control, though it adds an herbicide component.

A combined pre-emergent and post-emergent herbicide with 15-0-4 fertilizer brings weed control and lawn nutrition into one granular product. It is labeled for St. Augustine, Centipede, and Zoysia lawns, making it a focused option for buyers who want to address weeds while feeding compatible turf in early spring.

The dual pre- and post-emergent herbicide action addresses weeds at different stages, while the 15-0-4 fertilizer mix feeds the lawn as part of the same treatment. Its granular form is suited to a spreader-based workflow, although application varies by footage and the label supplies the instructions. Early-spring application is specified for seasonal lawn health and weed defense. The product explicitly excludes Bermuda and northern grasses, so checking grass type is essential before choosing it.

Skip it if you have Bermuda or northern grass; Scotts Green Max Lawn Food, which is listed for any grass type, is a broader option.

Choose this for a compatible St. Augustine lawn when combining weed management and feeding is the priority. It is not a universal turf treatment: the label excludes Bermuda and northern grasses, and application depends on footage.

Listed on Amazon as: Fertilome (13915) St. Augustine Weed & Feed 15-0-4, 12.8 lbs

#5 · Targeted Liquid Option

5. TPS St. Augustine Liquid Fertilizer

• Form: Liquid

Best for: Liquid St. Augustine root support.

Why it ranks #5: Specifically targets St. Augustine and is a fast-absorbing liquid intended to support deep green color and roots.

A fast-absorbing liquid formula pairs lawn greening with support for deep roots, giving St. Augustine owners a way to target color and root development together. The 8-ounce product is specifically described for this grass, with root benefits tied to water and nutrient uptake in warm climates and areas with heavy use.

The liquid form is described as fast absorbing, so its nutrients are delivered efficiently for growth, color, and turf health. Its stated deep-root support connects to better water and nutrient uptake, a useful focus for lawns facing warm conditions or heavy use. The product also emphasizes thicker, greener growth. The supplied details do not specify coverage, dilution, or application equipment, so buyers should not assume a particular treatment area or spray workflow from the title alone.

Skip it if you need stated square-foot coverage before applying; Scotts Green Max Lawn Food F lists coverage for 10,000 square feet.

This fits St. Augustine owners seeking liquid feeding focused on color and root development, particularly in warm climates or high-use areas. The 8-ounce size is stated, but coverage and application directions are not supplied here.

Listed on Amazon as: St Augustine Grass Fertilizer, Liquid Lawn Food for Thicker Growth, 8 oz

#6

6. Scotts Green Max Florida Fertilizer

• Weight: 30.3 lb
• Form: Granules

Best for: Florida lawn fast-greening feed.

Why it ranks #6: The Florida-labeled formula applies to any grass type and lists deep greening in three days, with 5.17% iron and feeding up to three months.

Scotts Green Max Florida fertilizer combines deep greening in three days with feeding for up to three months, giving Florida lawn owners both a quick color objective and extended feeding. It is listed for any grass type and covers 10,000 square feet, including St. Augustine lawns.

The dual-action lawn food uses 5.17% iron to enhance greening, with the stated deep-color timeframe of three days. Feeding lasts up to three months, so the formula serves more than a short-term color purpose. Its 10,000-square-foot coverage supports planning for a substantial Florida lawn, and the product may be applied any season to any grass type. Immediate re-entry is permitted after application, a useful detail for households managing lawn access.

Skip it if you need a Scotts Green Max option not limited to Florida; Scotts Green Max Lawn Food 16.67 lbs is listed for any grass type.

Florida homeowners seeking a fast color response, extended feeding, and broad grass-type compatibility may find this a match. Its Florida-only designation is the key boundary, despite the any-grass-type application claim.

Listed on Amazon as: Scotts Green Max Lawn Food F – Florida Fertilizer, 10,000 sq. ft.

#7

7. Scotts Green Max Lawn Food

• Weight: 16.7 lb
• Form: Granules

Best for: Fast-greening iron lawn food.

Why it ranks #7: Works on any grass type and contains 5% iron for greening in three days, but the listing does not specifically identify St. Augustine.

A 2-in-1 formula pairs lawn feeding with iron supplementation for deep greening in three days, giving St. Augustine owners a clear color-focused use. This 16.67-pound granular product covers 5,000 square feet, applies to any grass type, and is guaranteed not to stain when used as directed.

The formula contains 5% iron, which is identified as the micronutrient supporting its fast greening, while each granule is described as 100% nutrition with no filler. Scotts specifies spring, summer, or fall application using a Scotts spreader, providing a clear seasonal and equipment workflow. The stated 5,000-square-foot coverage helps define the treatment area, and immediate re-entry is allowed after application. It is not sold in Florida, an important location limitation for buyers comparing Scotts Green Max options.

Skip it if you live in Florida; Scotts Green Max Lawn Food F is the Florida-specific Green Max option in this group.

Choose this for a color-focused granular feed if the 5,000-square-foot coverage and Scotts-spreader application suit your lawn. Its any-grass-type claim includes St. Augustine, but Florida residents need the Florida-specific option.

Listed on Amazon as: Scotts Green Max Lawn Food, 16.67 lbs.

#8

8. Simple Lawn Solutions 16-4-8

• Weight: 2 lb
• Form: Liquid

Best for: Hose-end balanced liquid lawn food.

Why it ranks #8: Its 16-4-8 liquid formula is listed for any grass type and supplies nitrogen, phosphorus, and potassium, but is not St. Augustine-specific.

A ready-to-use sprayer and balanced 16-4-8 NPK formula let homeowners apply liquid lawn food through a garden hose, without handling loose granules. The blend also contains seaweed and fish, and it is described for all grass types, including Bermuda, making it a flexible spring and summer feeding option.

The included ready-to-use sprayer connects to a water hose, and the directions call for shaking the bottle before attaching and spraying evenly over the lawn. That workflow makes this liquid formula a practical choice for buyers who prefer hose-end application. Its 16-4-8 blend supplies nitrogen, phosphate, and potash, while seaweed and fish are also listed. Because it is described for all grass types, it can serve mixed-turf settings; the supplied details do not state coverage.

Skip it if you need a St. Augustine-specific slow-release product with stated coverage; Sunniland St. Augustine Lawn Fertilizer lists both.

Pick this if hose-end liquid application and a balanced NPK blend suit your spring or summer routine. Its all-grass-type description offers flexibility, but buyers needing a defined coverage area or St. Augustine-specific formula should weigh that boundary.

Listed on Amazon as: Advanced 16-4-8 Balanced NPK – Lawn Food Quality Liquid Fertilizer – Spring & Summer Concentrated Spray – Any Grass Type – Simple Lawn Solutions (32 Ounce)

#9

9. Pennington Full Season Fertilizer

• Weight: 11.2 lb
• Form: Granules

Best for: Season-long slow-release granules.

Why it ranks #9: Offers 32-0-5 nutrition, 5% iron, and controlled-release nitrogen for up to four months, but its listed grass types do not include St. Augustine.

Polymer-coated urea releases nitrogen for up to four months, letting one application feed a lawn for a season. Pennington pairs that extended release with 5% iron for deep greening and beneficial microorganisms for soil care, making this granular 32-0-5 formula a low-frequency feeding option.

The up-to-four-month controlled release is the central workflow advantage: the product is described as one application for the season, with spreader use per package directions. Its 32-0-5 formula combines high nitrogen with potassium, while 5% iron supports deep green color. Natural beneficial microorganisms are included to revitalize soil. The supplied grass list names Kentucky bluegrass, tall fescue, Bermudagrass, and Zoysiagrass, among others, but does not specifically name St. Augustine; availability excludes Hawaii and South Dakota.

Skip it if you require an expressly listed St. Augustine formula; Lawn Synergy Emerald 10-0-20 names St. Augustine among its grasses.

This is a fit for buyers prioritizing infrequent spreader application, slow nitrogen release, and iron-supported color. Since the supplied grass list does not specifically name St. Augustine, choose it only if its stated compatibility information meets your needs.

Listed on Amazon as: Pennington Full Season Lawn Fertilizer 4M 32-0-5 RF 3/11.2Lb

#10

10. Simple Lawn Solutions 3-18-18

• Weight: 3 lb
• Form: Liquid

Best for: Root-vigor phosphorus-potassium liquid.

Why it ranks #10: This any-grass liquid is aimed at phosphorus or potassium deficiency, not general yellowing; its 3-18-18 formula supplies little nitrogen.

A 3-18-18 liquid formula puts phosphorus and potassium well ahead of nitrogen, targeting root vigor and lawn hardiness rather than a conventional high-nitrogen feed. Simple Lawn Solutions presents it for summer and fall use and for maintaining lawn vigor or treating nutrient deficiencies, making its nutrient emphasis the key buying consideration.

The high-phosphorus, high-potassium ratio is intended to promote vigorous roots and support a stronger lawn, while the liquid form allows concentrated spray application. The product is positioned for summer and fall nutrients and for lawns showing phosphorus or potassium deficiency symptoms. That makes it a more targeted choice than a general greening formula; the supplied facts do not specify coverage or a complete application schedule. Phosphorus runoff is a stated concern, and some states restrict phosphorus lawn fertilizer.

Skip it if you need a phosphorus-free formula; Sunniland St. Augustine Lawn Fertilizer 20-0-6 is listed without added phosphorus.

Consider this liquid when root vigor or a stated phosphorus and potassium deficiency is the priority. It is not the natural fit for a phosphorus-free feeding plan, and local restrictions on phosphorus-containing lawn fertilizer matter.

Listed on Amazon as: Ultimate 3-18-18 NPK- Lawn Food Quality Liquid Fertilizer- Easy to Use Concentrated Spray- Any Grass Type- Summer & Fall Nutrients- Simple Lawn Solutions – Turf Hardiness & Root Vigor (32 Ounce)