Dead St. Augustine Grass? These 7 Tips Will Revive Your Lawn

Mariel Loveland
Written by Mariel Loveland
Updated June 7, 2022
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Bring your seemingly dead grass back to life

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St. Augustine grass is a warm-season turf grass that you’ll commonly find along the Gulf Coast and in Southern and Central California. In warm climates, it’s shockingly resilient—with excellent tolerance against heat and humidity—but it doesn’t have the same drought tolerance and cold resistance as other warm-season perennial grasses like Zoysia grass. 

In other words: if you’ve noticed brown spots on your once-green lawn, you’re hardly alone. Here’s what you can do to revive dead St. Augustine grass.

1. If Your Grass Is Dormant, Wait It Out

Is your St. Augustine grass browning? Even if your entire lawn turns a very crispy (read: dead-looking) shade of yellow-brown, it may not be the nail in the coffin. 

St. Augustine grass goes dormant when temperatures dip below 55 degrees Fahrenheit, which causes discoloration as growth slows down. As long as you’ve continued with regular lawn maintenance, it should green up when warm weather returns.

2. Perform a Soil Test—and Listen to the Results

If you’re experiencing yellowing or thinning grass, take a look at your soil. St. Augustine grass thrives in fertile, well-draining soil that’s slightly acidic—unfortunately, not all soils are created equal. A soil test should be able to tell you what’s needed. 

The cost of a soil test depends on how extensive you want to go. You can either purchase a kit from a garden center (for as little as $15) or hire a local soil testing company to perform a more extensive test (for a few hundred). You may need to fertilize or add amendments that alter the pH.

3. Make Sure You’re Watering Correctly

Close-up of a sprayer watering the lawn
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Watering is one of the most common St. Augustine grass problems. It’s just as easy to kill your lawn with overwatering as it is with underwatering. The exact amount and frequency should depend on the weather and the season. 

As a general rule:

  • Give your lawn 1–1.5 inches of water each week.

  • Spread the amount across one or two waterings.

  • In particularly hot weather, spread the amount across three waterings.

  • Allow the water to penetrate the soil 6 inches deep.

  • Water in the morning. This allows soil to dry and staves off fungus.

You may also want to consider hiring a lawn irrigation service to install a sprinkler system. Sprinklers will water your lawn evenly and help you maintain a watering schedule.

4. Dethatch and Aerate Your Lawn

Just like people, grass needs oxygen and nutrients. When it’s starved, you might notice your St. Augustine grass developing brown tips that eventually spread to the whole blade. Both compacted soil and thatch (the decomposing organic matter that builds up your lawn after mowing) could be to blame.

If more than half an inch of thatch accumulates, it can prevent your grass from absorbing the right amount of water, nutrients, and oxygen. The same goes for compacted soil, where oxygen can’t freely reach the roots. To solve the problem, hire a local lawn care service to dethatch and aerate your lawn. Dethatching breaks up the thatch, and aeration breaks up compacted soil.

5. Treat Any Existing Lawn Disease

If you’re dealing with dead St. Augustine grass, a lawn disease might be to blame. This type of turf grass is particularly susceptible to common lawn diseases like brown patch disease, gray leaf spot, and certain types of root rot. 

These fungal diseases tend to sneak in when your lawn is vulnerable and exposed to excess moisture. The treatment varies—from fungicides to dethatching and aeration—so call a professional.

6. Banish Pests

Technicians doing a pest control on lawn
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In some cases, your St. Augustine grass dead spots could be caused by an insect infestation. During an infestation, grubs or other insect larvae feed on the roots of your grass, causing yellowing and browning in uniform patches. You might even catch a few hungry birds pecking at your lawn looking for a meal. 

There are a few ways to get rid of pests—from insecticides and DIY bug sprays to pathogens and beneficial nematodes. Consider hiring a local lawn pest control service to clear the infestation without killing your grass.

7. Re-Think Your Fertilizer Application

There are a few common mistakes that may be killing your lawn, but over-fertilization is one of the quickest bad habits to curb. Excess nitrogen can damage roots and give blades a literal chemical burn. If you notice areas of scalding, there’s no miracle cure. Dead grass won’t rise from the grave, but you can prevent further damage by altering your fertilization methods. 

As a general rule, fertilize St. Augustine grass every six to eight weeks, but check the directions on your fertilizer. Don’t fertilize while grass is dormant, avoid watering on very hot days, and always water after applying fertilizer.

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