Best St Augustine Fertilizer

Annabelle Evans

By Annabelle Evans

| Updated 3 Days Ago

  • St. Augustine grass is a popular choice for lawns in warm, coastal, and southern regions, known for its ability to thrive in hot, humid climates and create a dense, lush carpet. To maintain its health and appearance, proper fertilization is essential, helping to boost growth, enhance color, and improve resistance to pests and diseases. The best fertilizer for St. Augustine grass depends on factors like the growing season, soil pH, and existing nutrient levels—soil testing can be helpful. When selecting a fertilizer, focus on the NPK ratio (nitrogen, phosphorus, and potassium), as St. Augustine typically requires more nitrogen. Slow-release formulas are ideal for feeding the lawn over time. We tested several fertilizers to find the best options for keeping St. Augustine grass healthy and vibrant.

  • Scotts WinterGuard Fall Fertilizer

    10

    We recommend this fertilizer for its ability to strengthen lawns before winter and promote healthy spring growth.

    10

    We recommend this fertilizer for its ability to strengthen lawns before winter and promote healthy spring growth.

    Pros

    • Builds deep roots for winter
    • Repairs summer damage
    • Works on all grass types

    Cons

    • Needs precise application
    • Results may vary
    • Pricier than some options

    We tried Scotts WinterGuard Fall Fertilizer on our lawn this season. It’s made to feed grass as it gets ready for winter. The bag says it helps fix damage from hot weather and lots of use over summer. We found it easy to spread with our lawn spreader.

    After using it, we noticed our grass looked greener within a week. The product claims to make roots stronger, but that’s hard for us to see. We like that it works on any kind of grass. This means you don’t need different products for different lawn areas.

    One thing to watch out for is using too much. We were careful to follow the instructions closely. Using too much could harm your grass instead of helping it. The price is a bit high, but a little goes a long way. We think it’s worth it to have a nice lawn come spring.

  • Scotts Southern Weed & Feed

    9.7

    We recommend this fertilizer for St. Augustine lawns due to its dual-action formula that feeds grass and kills weeds.

    9.7

    We recommend this fertilizer for St. Augustine lawns due to its dual-action formula that feeds grass and kills weeds.

    Pros

    • Kills many common southern weeds
    • Feeds grass to promote strong roots
    • Covers a large 5,000 sq. ft. area

    Cons

    • Only for certain grass types
    • Must be watered in right away
    • Not for use during winter dormancy

    We tried Scotts Turf Builder Bonus S Southern Weed & Feed2 on our St. Augustine lawn. The granules spread easily with a standard spreader. After watering it in, we waited to see results.

    Within a few weeks, we saw a noticeable change. Many weeds started to yellow and die off. The grass looked greener and seemed to fill in bare patches. It did a good job on common weeds like clover and dandelions.

    One downside is that it didn’t work on all weeds. Some tough ones hung on. Also, you can’t use it on all grass types or during winter. But for St. Augustine and similar grasses, it’s a solid choice to feed your lawn and fight weeds at the same time.

  • Lesco St. Augustine Booster

    9.5

    We recommend this fertilizer for its excellent results on St. Augustine lawns, especially in cooler weather.

    9.5

    We recommend this fertilizer for its excellent results on St. Augustine lawns, especially in cooler weather.

    Pros

    • High iron content for deep greening
    • Covers a large area
    • Professional-grade formula

    Cons

    • Pricey compared to some options
    • Requires careful application
    • May be too strong for weak lawns

    We tried this Lesco fertilizer on our St. Augustine grass, and the results were impressive. The granules spread easily and dissolved quickly with watering. Within a week, we noticed a marked improvement in the lawn’s color and thickness.

    The high iron content really made a difference. Our grass took on a rich, deep green that stood out from neighboring yards. It’s clear why pros often choose this brand for their clients’ lawns.

    We found the coverage to be spot-on. One bag treated our entire 12,000 square foot yard as promised. While it’s not the cheapest option, we think the quality justifies the cost. Just be careful not to over-apply, as it can be strong stuff.

  • Scotts Green Max Lawn Food

    9.4

    We think this fertilizer is a great choice for anyone wanting a greener lawn fast.

    9.4

    We think this fertilizer is a great choice for anyone wanting a greener lawn fast.

    Pros

    • Quick greening in 3 days
    • Works on all grass types
    • Won’t stain concrete

    Cons

    • Needs careful application
    • Requires watering for best results
    • May not work in all conditions

    We tried Scotts Green Max on our own lawns and were amazed by the results. The grass turned a deep, rich green in just a few days. It’s nice to see a product that lives up to its promises.

    One thing we liked was how easy it was to use. We just followed the instructions on the bag and used a spreader to apply it evenly. The granules dissolved quickly when we watered the lawn.

    We did notice that some spots got greener than others at first. This was likely due to uneven spreading on our part. It’s key to take your time and apply it carefully. After a second, more careful application, our lawns looked much more even.

  • Simple Lawn Solutions Balanced Fertilizer

    9.3

    We think this liquid fertilizer is a solid choice for most lawns, offering easy application and quick results.

    9.3

    We think this liquid fertilizer is a solid choice for most lawns, offering easy application and quick results.

    Pros

    • Easy to apply liquid formula
    • Works on many grass types
    • Contains seaweed and fish for added nutrients

    Cons

    • May need frequent reapplication
    • Requires careful measurement
    • Some users report diluted effects

    We tried this fertilizer on our test lawn and saw noticeable results within weeks. The grass looked greener and felt thicker under our feet. We liked how simple it was to mix and spray, saving us time compared to spreading granules.

    The 16-4-8 blend seemed to give our grass a good balance of nutrients. We noticed new growth and a deeper green color, especially in areas that were looking a bit thin before. The addition of seaweed and fish gave us confidence that we were feeding our lawn with natural ingredients.

    We found that it worked well on different grass types in our test plots, from St. Augustine to Kentucky Bluegrass. This versatility is great for lawns with mixed grass varieties. Just be aware that you might need to apply it more often than granular fertilizers for lasting results.

  • Scotts Fall Weed & Feed

    9.1

    We think Scotts Fall Weed & Feed is a solid choice for fall lawn care, offering weed control and nutrients to prepare grass for winter.

    9.1

    We think Scotts Fall Weed & Feed is a solid choice for fall lawn care, offering weed control and nutrients to prepare grass for winter.

    Pros

    • Kills over 50 types of weeds
    • Strengthens grass roots for winter
    • Easy to apply with a spreader

    Cons

    • Not for use on all grass types
    • Requires specific weather conditions
    • Must keep pets off treated areas

    We tested Scotts Fall Weed & Feed on our lawn this autumn. The granules spread easily with a standard rotary spreader. We made sure to apply it when the grass was damp and temperatures were between 60-90°F for best results.

    After a few weeks, we noticed fewer weeds in our yard. The dandelions and clover that had been popping up were gone. Our grass also looked greener and felt thicker underfoot. It seemed like the fertilizer was helping prepare the lawn for the cold months ahead.

    One downside we found is that you can’t use this product on certain grass types like St. Augustine. You also need to keep pets off the lawn for a while after applying. But for compatible grasses, we think this 2-in-1 weed killer and fertilizer does a good job getting lawns ready for winter. The 14.29 lb bag covers 5,000 sq ft, which was enough for our modest-sized yard.

  • Scotts Southern Triple Action

    9

    We think this 3-in-1 lawn care product is a great choice for Southern grass owners looking to tackle weeds, fire ants, and fertilization in one go.

    9

    We think this 3-in-1 lawn care product is a great choice for Southern grass owners looking to tackle weeds, fire ants, and fertilization in one go.

    Pros

    • Kills common weeds and fire ants
    • Feeds grass to fight heat and drought
    • Covers a large 8,000 sq. ft. area

    Cons

    • Only for specific Southern grass types
    • Needs immediate watering after use
    • May cause burned spots in hot weather

    We tried Scotts Southern Triple Action on our St. Augustine lawn, and we were happy with the results. The granules were easy to spread using a standard rotary spreader. After watering it in, we noticed fewer weeds within a week.

    The fire ant control was a big plus. We saw a big drop in ant mounds across our yard. The fertilizer also gave our grass a nice green boost, helping it look lush even during a dry spell.

    We did notice some burned spots in areas where the product may have clumped. It’s key to spread it evenly and water right away. This product works on St. Augustine, Centipede, Zoysia, and Carpet grass. If you have these types and want an all-in-one solution, give it a try.

  • Simple Lawn Solutions 3-18-18 Fertilizer

    8.7

    We think this liquid fertilizer is a solid choice for boosting lawn health and tackling nutrient deficiencies.

    8.7

    We think this liquid fertilizer is a solid choice for boosting lawn health and tackling nutrient deficiencies.

    Pros

    • Easy-to-use hose-end sprayer
    • High phosphorus and potassium content
    • Works on all grass types

    Cons

    • May require multiple applications
    • Spray nozzle can be tricky to operate
    • Results may vary depending on lawn conditions

    We tried out the Simple Lawn Solutions 3-18-18 fertilizer on our test lawn and were happy with the results. The liquid formula mixed well and spread easily using the attached sprayer. It took us about 20 minutes to cover our 3,000 square foot yard.

    After a few weeks, we noticed our grass looked greener and felt thicker underfoot. The high phosphorus seemed to help strengthen the roots, while the potassium gave the lawn extra resilience. We liked that it worked on our mix of grass types without any issues.

    One downside we found was that the spray nozzle could be a bit finicky to adjust. It took some fiddling to get the right spray pattern. We also needed to do a couple of applications over the season to maintain the results. Still, for an easy-to-use liquid fertilizer that tackles multiple lawn needs, this product did the job well.

  • Scotts Southern Turf Builder

    8.7

    We think this fertilizer is a great choice for anyone looking to boost their Southern lawn’s health and appearance.

    8.7

    We think this fertilizer is a great choice for anyone looking to boost their Southern lawn’s health and appearance.

    Pros

    • Fast-acting formula
    • Strengthens grass against heat and drought
    • Safe for all Southern grass types

    Cons

    • May require frequent applications
    • Not ideal for cool-season grasses
    • Can be pricey for large lawns

    We tried Scotts Southern Turf Builder on our St. Augustine grass, and we were impressed with the results. Within days, our lawn started looking greener and more lush. The granules spread easily and dissolved quickly, leaving no mess behind.

    One thing we liked was how this fertilizer helped our grass handle the hot Southern summers. Our lawn stayed green even during dry spells, which we think is due to the deeper root growth this product promotes. We didn’t have to water as much as usual, which was a nice bonus.

    We found this fertilizer to be very user-friendly. It works on wet or dry lawns, so we didn’t have to plan around the weather. The coverage was good too – one bag treated our whole 5,000 sq. ft. yard. While it’s a bit more expensive than some other options, we think the results make it worth the cost for most Southern homeowners.

  • Ferti-lome Lawn Winterizer

    8.6

    We recommend this Ferti-lome Winterizer for its balanced nutrient mix that prepares lawns for cold weather.

    8.6

    We recommend this Ferti-lome Winterizer for its balanced nutrient mix that prepares lawns for cold weather.

    Pros

    • Low nitrogen content prevents excessive growth
    • Strengthens roots and stems for winter
    • Suitable for various plants and trees

    Cons

    • Only available in larger 20-pound bags
    • Requires careful application to avoid overfeeding
    • May not be ideal for warm-season grasses

    We tested this Ferti-lome Winterizer on our lawns and were impressed with the results. The 10-0-14 formula is perfect for fall application, providing just enough nutrients without promoting too much growth before winter.

    The granules spread easily and dissolve well with watering. We noticed our grass looked healthier and more resilient after using this product. It’s not just for lawns either – we tried it on some ornamental shrubs, and they seemed to weather the cold months better than usual.

    One thing to keep in mind is the bag size. At 20 pounds, it’s more than some homeowners might need for a single season. We found it best to store the leftover product in a cool, dry place for next year. The coverage is good though, treating up to 5000 square feet per bag.

Buying Guide

We recommend looking at a few key factors when choosing St. Augustine fertilizer:

Nutrient Ratio

The NPK ratio (nitrogen, phosphorus, potassium) is crucial. St. Augustine grass typically needs:

  • High nitrogen (N)
  • Moderate phosphorus (P)
  • Moderate potassium (K)

A ratio like 16-4-8 or 15-0-15 often works well.

Slow-Release Formula

Slow-release fertilizers feed the grass steadily over time. This promotes even growth and reduces the risk of burning.

Iron Content

Iron helps keep St. Augustine grass green. Look for fertilizers with added iron for the best color.

Application Method

Consider how you’ll spread the fertilizer. Options include:

  • Granular (for spreaders)
  • Liquid (for sprayers)
  • Water-soluble (for hose-end applicators)

Pick what’s easiest for your lawn size and tools.

Seasonality

Some fertilizers are formulated for specific seasons. Using the right one at the right time can boost results.

Organic vs Synthetic

Organic fertilizers are eco-friendly but work slower. Synthetic options act faster but may be harsher on soil life.

We suggest testing your soil before buying. This helps pinpoint exactly what nutrients your lawn needs.