Lawn Fertilizer for St. Augustine Grass


lawn fertilizer for st augustine grassHere in North Texas, we have some really lovely varieties of grass to choose from for landscaping. St. Augustine grass is among the favorites for its deep green, broad blades that provide a thick and comfortable ground cover. You need to know all the details about lawn fertilization for St. Augustine grass.

Every experienced lawn care enthusiast knows that feeding your lawn the proper nutrients is vital to keeping it verdant, radiant, and appealing. But it’s not as simple as buying a bag of weed-and-feed. 

Just like growing vegetables in a garden, you need to know exactly what a plant needs in order to thrive. And- that’s right- that concept absolutely includes your grass.

Let’s say you’re a relatively new homeowner, and you’ve discovered your lawn is filled with St. Augustine grass. Or perhaps you’ve been in your home for awhile, and you’re frustrated with the fact that your lawn is suffering despite your best efforts.

We have the knowledge you need, to restore and maintain your St. Augustine grass to its full beauty, so you can enjoy a luscious lawn. 

Get help with your lawn fertilization schedule. 

Check For Intruders

White grubs, chinch bugs, ants, and other small intruders can compromise the health of your lawn. A good step toward hardy grass is to check for infestations. Small dirt mounds and yellow spots are a decent indicator of unwanted bugs.

Do some digging in the dirt to discover who exactly is invading your space. Take some pics, do some online research, and go to your local garden shop to identify who you’re dealing with. Talking with an expert is always the best way to effectively combat unwanted visitors in your yard.

Once you’ve identified the predators, take appropriate action. Be sure you use products that won’t harm your lawn! After all, the end game is to maintain a beautiful yard without causing further damage when addressing harmful invaders.

Test Your Soil’s pH Level

This is a great way to determine what your grass actually needs. It can also be an effective measure for reducing intrusive weeds.

Did you know that some invasive species (such as clover) thrive on low-nitrogen soil? Running a quick pH test can help determine why your grass isn’t thriving, as well as which weeds your lawn might be at risk for.

Know How Much Lawn Fertilizer to Use

All St. Augustine grass turfs require a nitrogen-rich fertilizer. However, there are many different opinions about which ratio is best, which is why checking your soil’s pH is important.

Some experts recommend 6.5lb per 1,000 square feet, while others say that 4lb per 1,000 square feet is best. That is quite a difference! The default is 1lb per 1,000 square feet.

However, all of this depends on your soil, your sub-type of grass, your sun exposure, and myriad other contributing factors. We recommend defaulting to 1lb/1,000 sq ft, but if this isn’t yielding satisfactory results, then you should always consult a professional.

Know Which Lawn Fertilizer to Use for St. Augustine grass

Most fertilizers sold in our region consist of nitrogen, phosphorous, and potassium. There are several different ratios to choose from. It’s important to learn to read your ratios accurately before bringing home a bag of something that may or may not adequately fertilize your St. Augustine grass.

For instance, a 16-4-8 ratio is the same as a 4-2-1 ratio, when it comes to the amount of nitrogen, phosphorous, and potassium it yields. However, the 16-4-8 will be more potent, because the numbers are also indicative of other ingredients in the product.

Knowing this information is important when it comes to choosing how and when you’re going to fertilize your lawn. Perhaps you want a more potent mix during active growing seasons (typically around mid-May), but a milder mix the rest of the time.

How Often Should I Fertilize My St. Augustine Grass

Fertilizers consist mainly of naturally occurring compounds. But that doesn’t mean they aren’t potentially dangerous chemicals. For instance, over-fertilizing your St. Augustine grass when it’s too hot can burn your turf. It’s important to know how various products affect your lawn.

Instant-release fertilizers are best applied around May and September, when the average daily temperatures are not exceeding 90*. This is also when most grasses are growing most vigorously. Therefore, it’s a great time to feed your rapidly growing lawn without risking heat-induced harm.

Slow-release fertilizers take about 10 weeks to fully absorb, and it’s important to water your grass after applying them. This is a great option just before the temperatures rise, as you can feed your grass for several weeks to come, without worrying about quick-release chemicals having a negative interaction with the summer sun.

Mixed-release products are optimal for the North Texas region. We all know that, between mid-spring and early summer, the daily temperatures can become quite unpredictable. But with a mix of instant- and slow-release nitrogen, your St. Augustine grass will be verdant and well-fed no matter what.

Lawn Fertilizing for St. Augustine Grass Schedules

Knowing when to apply fertilizer is important, but understanding the importance of an effective yearly schedule is a full step ahead when it comes to lawn care.

We’ve discussed when to apply fertilizer to your St. Augustine grass in the spring and fall, but what about the rest of the year? It’s important to know the do’s and don’ts for fertilizing your St. Augustine grass.

Generally speaking, every 8 weeks is a healthy application schedule. However, this really depends upon the weather and climate patterns in your direct region. Once again, you do not want to apply harsh chemicals when it’s exceedingly hot- or during a hard freeze.

For early spring, it’s recommended to apply fertilizer about 3 weeks after your St. Augustine grass begins to green. This can be followed by a heartier dose of nutrients during peak growing season (as mentioned above).

You do NOT want to fertilize in the dead of winter, but any dedicated lawn enthusiast still wants to ensure their yard will remain healthy from one season to the next. For this, we recommend a final application in the autumn, before overnight temperatures reach the freezing point, and before your grass becomes fully dormant.


While St. Augustine grass is a rich and hearty favorite for North Texas lawns, it does require a bit of care to remain healthy year-round. Be sure you adhere to proper lawn fertilization methods in order to nourish your lawn and guarantee that it stays beautiful from one season to the next.

Read on for more lawn care tips from our pros at JC’s Landscaping, LLC!

Picture of Janice Nelson

Janice Nelson

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