Best 16-4-8 Fertilizer For St Augustine Grass

#1 · Best Overall

1. The Andersons PGF Complete

• Weight: 18 lb
• Form: Granules

Best for: Granular feeding with humic DG.

Why it ranks #1: This all-turf 16-4-8 granular formula adds iron, micronutrients, and Humic DG, with quick- and slow-release nitrogen feeding for up to eight weeks.

Super-fine granules deliver twice the number of particles per square foot, a feature intended to help distribute this 16-4-8 fertilizer evenly across turf. Quick- and slow-release nitrogen feed immediately and continue feeding for up to eight weeks, making it a fit for homeowners seeking extended granular nutrition.

The fine-particle formulation is paired with iron, micronutrients, and 7% Humic DG, so the product combines macronutrients with listed supplementary ingredients in one granular fertilizer. Quick- and slow-release nitrogen supports both immediate and extended feeding, with nutrition lasting up to eight weeks and reapplication suggested every six to eight weeks. It is listed as safe for all turf types during the growing season, which includes a broad turf-use window, but application requires a spreader routine and protective gear.

Skip it if you prefer a hose-end liquid application; Simple Lawn Solutions Advanced 16-4-8 uses a ready-to-use sprayer instead.

This suits St. Augustine owners comfortable applying granules who want fine particle distribution and feeding that can extend up to eight weeks. Follow the listed protective-equipment precautions, and note that the product is not for sale in California.

Listed on Amazon as: The Andersons Professional PGF Complete 16-4-8 Fertilizer with 7% Humic DG 5,000 sq ft

#2 · Longest Release

2. Reed & Perrine Turf Fertilizer

Best for: Extended-release southern lawn feeding.

Why it ranks #2: Its 16-4-8 formula is described for southern lawns and claims a three-to-four-month release, making it a regionally relevant granular choice.

A stated three-to-four-month release time sets this 16-4-8 turf fertilizer apart for homeowners planning a longer feeding interval. Its description also identifies iron and use on southern lawns in cool temperatures, with spring application suggested to jump-start turf greening.

The product is listed to cover 8,000 to 10,000 square feet, giving buyers a stated range for planning a granular application. Its three-to-four-month release time supports a longer feeding window than products described with shorter intervals. The description specifically mentions iron for greening southern lawns when temperatures are cool and suggests spring use. These points make it relevant to St. Augustine care in a southern setting, but no spreader compatibility or detailed application rate is supplied.

Skip it if you need spreader guidance or a detailed application rate; those directions are not included in the supplied product facts.

This may suit St. Augustine owners in southern regions planning spring feeding and seeking a longer stated release period. Its listing gives a coverage range, but does not provide spreader compatibility or a detailed application rate.

Listed on Amazon as: The Andersons | Reed & Perrine Turf Fertilizer 16-4-8

#3 · Best Hose-End Liquid

3. Simple Lawn Solutions 16-4-8

• Weight: 2 lb
• Form: Liquid

Best for: Hose-end liquid feeding.

Why it ranks #3: This liquid 16-4-8 lawn food includes seaweed and fish, suits all grass types, and uses a ready-to-use hose-end sprayer.

A hose-end sprayer application makes this 16-4-8 liquid lawn food a straightforward option for feeding St. Augustine without spreading granules. Its balanced nitrogen, phosphorus, and potassium formula is intended to support greening, growth, and root vigor, while seaweed and fish add distinguishing ingredients to the blend.

The ready-to-use sprayer connects to a water hose, so the listed application steps involve shaking the bottle, attaching it, and spraying evenly over the lawn. That liquid format suits a homeowner who prefers hose-end coverage to a spreader routine. The 16-4-8 NPK supplies the stated macronutrient balance, and seaweed and fish are also included. The product is listed for all grass types, including Bermuda, though the supplied details do not give a St. Augustine-specific application rate.

Skip it if you need a stated lawn coverage area before applying; the supplied product details do not provide one.

This fits St. Augustine owners who want a hose-connected liquid application and a balanced NPK blend with seaweed and fish. Check that the unspecified coverage rate works for your lawn-care routine before choosing it.

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)

#4 · Best Humate Liquid

4. PetraMax 16-4-8 Liquid

• Weight: 9 lb
• Form: Liquid

Best for: Balanced liquid with humates.

Why it ranks #4: This all-grass liquid supplies the requested 16-4-8 ratio and includes high-purity humates and supplementary potassium for root support.

High-purity humates and supplementary potassium distinguish this Petra 16-4-8 liquid, with the listing connecting those ingredients to deeper root development. Its nitrogen, phosphorus, and potash blend provides balanced macronutrient support for all grass types, including buyers seeking a liquid lawn-food format.

The 16-4-8 nutrient formula supplies nitrogen for lawn growth and green color, while phosphorus and potassium contribute the other named macronutrients in the balanced blend. The product description specifically links high-purity humates and supplementary potassium with deeper root development, giving buyers a root-focused reason to consider it alongside routine feeding. Its liquid concentrate format is identified in the title. The supplied details do not state coverage or application directions, so planning an exact treatment requires consulting the product label.

Skip it if you need a stated coverage area or application directions before buying; neither appears in the supplied product facts.

This fits St. Augustine owners looking for balanced liquid NPK with humates and a stated root-development focus. The supplied facts do not give coverage or directions, so it is less straightforward to plan an application from the listing alone.

Listed on Amazon as: PetraMax Liquid Lawn Fertilizer for Lawns Concentrate – Liquid Fertilizer for Lawns, Food for Grass – 16-4-8 High Nitrogen Lush Green Grass, Phosphorus for Strong Roots – Apply Spring & Summer (1 G)

#5

5. PROXIO 16-4-8 Fertilizer

• Weight: 40 lb
• Form: Granules

Best for: Large-lawn granular coverage.

Why it ranks #5: This 40-pound granular 16-4-8 product covers 11,000 square feet and combines humates with quick- and slow-release nitrogen for up to eight weeks.

Coverage listed for up to 11,000 square feet gives this 40-pound 16-4-8 granular fertilizer a clear large-lawn use case. Its ultra-fine particles are said to cover twice the area per square foot, while quick- and slow-release nitrogen provides feeding for up to eight weeks.

The manufacturer says the fine granules work with most lawn spreaders, helping make application compatible with common spreading equipment. Humic DG and humic and fulvic acids are described as enriching soil and supporting nutrient uptake and root growth, adding a soil-focused element to the NPK blend. Quick- and slow-release nitrogen feeds for up to eight weeks. The 40-pound bag and stated 11,000-square-foot coverage suit larger turf areas, though the supplied facts do not specify a St. Augustine-specific rate.

Skip it if you have a small lawn and do not need a 40-pound bag or coverage up to 11,000 square feet.

This is a practical match for St. Augustine owners with a larger lawn, a spreader, and interest in humic ingredients alongside 16-4-8. Consider the 40-pound package size and use the product’s label for application directions.

Listed on Amazon as: Lawn Fertilizer 16-4-8 with Humates for Grass, 11,000 sq ft All Turf, 40lb

#6

6. Prevegenics 16-4-8 Liquid

• Weight: 10 lb
• Form: Liquid

Best for: High-coverage liquid maintenance.

Why it ranks #6: Its one-gallon liquid formula is listed to cover up to 42,000 square feet and includes iron, L-amino acids, and fulvic acid.

Coverage up to 42,000 square feet from a one-gallon container makes this liquid 16-4-8 a notable option for maintaining larger lawns. Its formula also lists iron, L-amino acids, and fulvic acid, alongside balanced NPK intended to support green-up and root development.

The one-gallon liquid format is paired with a stated maximum coverage of 42,000 square feet, a useful planning figure for buyers treating a broad turf area. The 16% nitrogen, 4% phosphorus, and 8% potassium formula is described as supporting green-up, root development, and nutrient translocation. Iron, L-amino acids, and fulvic acid are also named in the title. The supplied facts do not give a hose-end method or a St. Augustine-specific rate, so buyers should rely on product directions for application.

Skip it if you need a listed hose-end application method; the supplied product facts do not identify one.

This fits St. Augustine owners maintaining a large lawn who want liquid 16-4-8 and a stated maximum coverage figure. Confirm the product’s application directions for your turf and equipment, since the supplied details do not provide a method.

Listed on Amazon as: 16-4-8 Liquid Lawn Fertilizer | (1 Gallon) | with Iron, L-Amino Acids, and Fulvic Acid | Balanced Lawn Food for All Grass Types

#7

7. Simple Lawn Solutions 16-4-8 and Iron

• Weight: 2 lb
• Form: Liquid

Best for: Liquid feeding with iron.

Why it ranks #7: The bundle combines 16-4-8 lawn food with separate dark green liquid iron, adding a greening-focused companion to the requested nutrient ratio.

A bundle pairing 16-4-8 lawn food with dark green liquid iron gives St. Augustine owners two liquid products aimed at macronutrient feeding and deeper green color. The lawn food supplies nitrogen, phosphorus, and potassium, while the added iron product provides a separate color-focused part of the package.

The two-bottle bundle combines 32 ounces of 16-4-8 lawn food with 32 ounces of dark green liquid iron, so buyers get both products for a liquid lawn-care routine. The listing links nitrogen with greening and growth, phosphorus with plant and root development, and potassium with lawn support; the iron product is presented for deepening green color. This separates balanced NPK feeding from the iron component, but the supplied details do not state coverage or a combined application schedule.

Skip it if you need a clearly stated coverage area and application schedule for both products before planning treatment.

This bundle suits St. Augustine owners seeking liquid NPK feeding alongside a separate iron product for deeper green color. The supplied information does not specify coverage or a combined schedule, so check the product directions before coordinating applications.

Listed on Amazon as: 16-4-8 Liquid Lawn Food Fertilizer 32 Ounce + Dark Green Liquid Iron 32 Ounce Bundle – Simple Lawn Solutions

#8

8. Simple Lawn Solutions 16-4-8 Bundle

• Weight: 2 lb

Best for: Two-size hose-application bundle.

Why it ranks #8: This bundle pairs a 32-ounce ready-to-use bottle with a one-gallon 16-4-8 bottle, offering two liquid formats but no listed added nutrients.

A bundle containing a 32-ounce ready-to-use bottle and a one-gallon 16-4-8 bottle offers two package sizes for a liquid lawn-feeding routine. The listed hose connection and even-spraying directions make application familiar, while the balanced NPK formula is the central nutrient offering.

The smaller bottle is described as ready to use, and the directions say to shake, connect the bottle to a hose, and spray liquid evenly over the lawn. The bundle also includes a one-gallon 16-4-8 bottle, giving buyers both listed sizes in one purchase. Reapplication is recommended every four to six weeks. The directions caution against spraying flowers, vegetables, or other desirable plants, so careful targeting matters around mixed landscape beds.

Skip it if you cannot keep spray away from flowers, vegetables, and other desirable plants during lawn application.

This suits St. Augustine owners who want hose-applied liquid fertilizer and both a smaller ready-to-use bottle and a one-gallon bottle. It requires careful spraying around flowers, vegetables, and other desirable plants, with reapplication listed every four to six weeks.

Listed on Amazon as: Simple Lawn Solutions 16-4-8 32 Ounce + 16-4-8 1 Gallon Bundle – Liquid Lawn Food Fertilizer

#9

9. PetraTools 28-0-0 Liquid

• Form: Liquid

Best for: Nitrogen-focused liquid green-up.

Why it ranks #9: This nitrogen-focused 28-0-0 product does not match the requested 16-4-8 ratio, so it is a poor fit despite its liquid lawn application.

A 28-0-0 formula with 70% quick-release nitrogen targets rapid green-up and growth, making this Petra liquid a focused choice for nitrogen-deficient grass rather than a balanced 16-4-8 feed. Its remaining 30% slow-release nitrogen is listed for ongoing growth between applications.

The product is mixed with water in a sprayer and applied evenly, with directions suggesting one gallon per 1,000 square feet. That spray workflow gives buyers a stated application rate to plan around. Its quick- and slow-release nitrogen split aims to combine faster greening with continued growth, while the description also cites improved soil mineral content and denser-growing grass. Because the formula is 28-0-0, it does not supply the phosphorus and potassium of a balanced 16-4-8 product.

Skip it if you want balanced 16-4-8 nutrition; PetraMax Liquid Lawn Fertilizer 16-4-8 is the listed Petra option with phosphorus and potassium.

This is for St. Augustine owners addressing nitrogen deficiency who want a spray-applied nitrogen product and a stated rate. Choose a balanced NPK fertilizer instead when phosphorus and potassium are part of your feeding goal.

Listed on Amazon as: PetraTools Liquid Nitrogen Fertilizer (1G) Liquid 16-4-8 Lawn Fertilizer