Best Fertilizers for St. Augustine Grass

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Not all fertilizers are created equal. The difference between the best ones out there and an average one is drastic. It can mean the difference between a lifeless lawn and a luscious green lawn.

Giving your St. Augustine grass the right nutrients is essential for the well-being of your grass. It can be challenging to identify the best product to buy. You want a product that delivers the right nutrients to your St. Augustine grass’s root zone. In this post, I will take the frustration and guesswork out of choosing a high quality fertilizer for your lawn. Keep on reading my article to learn more!

Comparing Our Top 3 Recommendations

St augustine grass2

At a Glance

These are my top recommendations. They use quality ingredients and are much better than most other products on the market. Please keep reading below to learn more about each one. 

St augustine close up

Our Short Reviews

Andersons PGF Complete

My top recommendation is Andersons’ PGF Complete, particularly if you like dry fertilizer. It will give you a lawn that appears healthy and will put your neighbors to shame.


  • The N-P-K ratio of 16-4-8 is ideal for growing St. Augustine grass.
  • It contains 4% slow release nitrogen (methylene urea) that will continue to deliver nitrogen over an extended period of time as water slowly breaks down the nitrogen.
  • Each bag covers up to 5,000 square feet of lawn.
  • Anderson’s PGF Complete spreads well and evenly when used with a spreader. I advise you to water your lawn shortly after applying to ensure that the small granules do not get carried away by the wind.
  • Andersons’ formula is unique in that it contains Humic Acid, which helps to make your soil the correct pH. Most soil is too basic, so the acid brings the pH down to the right levels. Correct soil pH levels are essential to proper uptake of nutrients.


  • Perfect N-P-K ratio for St. Augustine grass
  • Slow release nitrogen
  • Contains humic acid for pH control
  • Small granules spread evenly
  • Great value


  • Not found at most retailers

Andersons PGF complete is our top recommendation. It has all the features that you would want in a product – ideal NPK ratio, slow release, and pH control.

Simple Lawn’s Lawn Food Natural Liquid Fertilizer

Simple Lawn’s product is a great option, particularly if you are looking for an organic option. Your lawn will be nice and healthy without the use of harsh chemicals.


  • Simple Lawn’s solution contains the ideal N-P-K ratio for St. Augustine grass (16-4-8)
  • It will cover a lawn that is roughly 3,500 square feet.
  • It is sold in multiple different size capacities, which is perfect for people with larger lawns. They sell it from sizes of 32 ounces to 2.5 gallons.
  • It uses organic feed grade ingredients without any harsh chemicals. This may be a consideration if you have young children or pets that frequently play out in the yard.
  • The company has over 25 years of experience and the product is made in the US.


  • Perfect N-P-K ratio for St. Augustine grass
  • Four Size Options Available
  • Manufacture in the US
  • Organic ingredients


  • No sustained release nitrogen

Simple Lawn Solutions liquid fertilizer is a great choice. It contains organic ingredients and has the ideal N-P-K ratio. It does not have slow release nitrogen, but I find that this matters less for St. Augustine grass compared to some other grass types.

LawnStar 16-4-8 NPK Fertilizer

Lawnstar’s liquid product is a great choice if you like using spray fertilizer. It has great value and will make your lawn grow in quickly and in a healthy manner.


  • It consists of an N-P-K ratio of 16-4-8, which is the exact N-P-K ratio that you want for St. Augustine grass.
  • It contains 6% urea triazone solution, which is a form of nitrogen that is slowly released over time. This allows your grass to stay green for longer.
  • Lawnstar has added natural seaweed extract into the solution to maximize the amount of macronutrients that is able to be taken up by the root zone.
  • This is a concentrated solution which allows you to treat lawns up to 4,000 square feet.
  • As with many other liquid nutrients, the container fits a standard hose to make applying it much simpler.


  • Perfect N-P-K ratio for St. Augustine grass
  • Slow release nitrogen
  • 4,000 Square Foot Lawn Size Capacity
  • Optimized with seaweed extract
  • Great value


  • Not sold at most retailers

Your St. Augustine grass will grow strong and healthy with Lawnstar’s product that has the perfect NPK ratio, slow release nitrogen, and the added bonus of having seaweed extract.

Scotts Turf Builder Starter Food Plus Weed Preventer

Scotts is the most well-known commercially available product that comes in multiple different packaging and nutrient ratios. In general, I find that they have so many different packages without clearly labelled N-P-K ratios that sometimes I find it hard to find what suits my exact needs. The product is pretty good, but there are better options out there (note I would not use this on Bermuda grass as it is sensitive to the Mesotrione ingredient)


  • Scott’s product contains Mesotrione, which prevents crabgrass and dandelion growth for up to 6 weeks.
  • The product is better at preventing new weed growth, rather than actually killing any existing weed
  • It has a N-P-K ratio of 21-22-4, which is more phosphorus than is ideal for St. Augustine grass.


  • 5,000 Square Foot Capacity
  • Prevents the growth of new weed
  • Sold at many retailers


  • Less than ideal N-P-K ratio for St. Augustine grass
  • Expensive
  • Does not get rid of existing weed
  • Not Sold in the state of Florida

Scotts’ Turf Builder 2-in-1 is great if you are looking to grow St. Augustine grass while also preventing the growth of new weed. I think there are better options out there, but it is still a great option.

Pendelton Turf and Supply Liquid Fertilizer Micronutrients

Pendelton Turf and Supply product will help your grass to start looking healthy in no time.


  • It has an N-P-K ratio of 18-3-6, which is slightly more in nitrogen than the ideal, but still works well with St. Augustine grass
  • Pendleton’s product is a high concentration ratio that is supposed to be mixed at a ratio of 50:1
  • This high concentration product covers roughly 2.5 acres of lawn.


  • 2.5 acre capacity
  • Slow release nitrogen
  • High concentration product


  • Not sold at many retail stores
  • Expensive

Pendleton’s product will fit your grass needs, but unfortunately is not always found at all brick and mortar stores. I recommend that you give it a try if you want a high concentration fertilizer that can cover a lot of lawn area.

Fertilizer for st augustine

Raising a Healthy Lawn

St. Augustine grass (stenataphrum secundatum) is a robust grass that looks beautiful when it is well tended to and fertilized well. It creates a dense carpet of coarse grass blades that have a blue-green color and can grow well even in shaded areas. To properly grow and maintain your lawn, you will need the ideal nutrients.

N-P-K Ratio

As you may know, every plant has different ideal NPK ratios. The ideal fertilizer for each type of grass or plant is dependent not only on the quality of the product, but also dependent on its specific NPK ratio. For St. Augustine grass, the ideal ratio is 4-1-2 so a product with a 16-4-8 or 20-5-10 ratio would be ideal. Remember, this ratio is important as too much nutrient is actually harmful for the grass and furthermore can make the ground a breeding ground for pests.

Do Not Over Feed or Water Your Lawn

Many people may not know this, but overfeeding or over watering your lawn can create as many issues as underfeeding it. This is slightly less of a problem in dry and hot environments where there is little water left in the soil after a sunny day, but just realize that if your soil is constantly moist it can cause your grass’s roots to rot. Too much nutrients can also create a breeding ground for pests and also lead to leaf burn.

Fertilizer for st augustine

Application Frequency

St. Augustine grass should be sprayed or spread with nutrients about once every 2 months during the warm seasons. That means that if you live in the north, you should be fertilizing your lawn from May through September a total of three times. If you live in the south, such as Florida, you should be fertilizing from April to October or even November. If you are using sustain release nutrients, then you can space your frequency of fertilizing to every 3 months

Bottom Line

Again, I recommend buying Anderson’s Complete Fertilizer . Don’t make the mistake of buy any average fertilizer at your local gardening store. Many of them will simply not produce the same results. You cannot go wrong with any of the choices above. 

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About the author: Carley Miller is a horticultural expert at TheGreenPinky. She previously owned a landscaping business for 25 years and worked at a local garden center for 10 years.

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