How Do You Dethatch St Augustine? All You Need To Know

Dethatching St Augustine grass will help eliminate pests and improve your lawn’s appearance. However, removing thatch may be risky, as it may damage your yard if not done correctly.

Pulling out thatch from St Augustine isn’t necessary if the inorganic matter is less than 0.5” thick. For a safe dethatching process, it’s advisable to water your lawn and mow it to 2” the day before. Use a mower or hand rake instead of a power rake to avoid damaging your yard.

This post discusses the causes of thatch in St Augustine and breaks down the dethatching process. Also detailed are suggestions on when to dethatch and precautions to take.

What Causes Thatch in St Augustine?

Thatch is the build-up of dead or inorganic matter at the base of the St Augustine grass. This inorganic matter may include grass clippings, small twigs, yard debris, compacted soil, and dead leaves.

Factors that could enhance the amount of thatch in your lawn include:

  • Limited soil aeration
  • Inadequate moisture
  • Overfertilization

Limited Soil Aeration

Poorly aerated soil has a higher chance of developing thatch. This is because organisms that promote thatch disintegration can’t thrive with limited aeration. Using a core aerator in your lawn’s turf soil is advisable to increase oxygen circulation.

Inadequate Moisture

Wet thatch decomposes faster than its dry counterpart. Therefore, leaving the thatch dry will allow it to keep building up, as the decomposition process is slower. Water your lawn regularly to avoid thatch accumulation and to ease the dethatching process.


Overfertilization causes St Augustine to grow faster. Faster growth promotes frequent mowing, which results in too many clippings. These clippings build up to form thatch in your lawn.

How to Dethatch St Augustine

Dethatching St Augustine isn’t as complicated as it sounds. However, ensure you use the right tools to avoid damage.

Below are steps you should follow for successful dethatching.

  • Mow your lawn to 2 inches
  • Water the lawn
  • Use a rake to dethatch small lawns
  • Use a mower to dethatch st Augustine grass (preferred method)

Step 1: Mow Your St. Augustine Lawn

You should mow your lawn to 2” before dethatching st Augustine grass. This gives the dethatcher an easy time as they can pull out the buried and thickened thatch without struggling. Two inches is also tall enough to prevent damaging the lawn. Avoid cutting the grass below one and a half inches as it increases the chances of the st Augustine grass dying.

Step 2: Water Your Lawn

Water your lawn twenty-four hours before dethatching to break apart the thick thatch layer. Watering the lawn also reduces the stress on the grass during dethatching, thus increasing its survival chances.

You shouldn’t overwater your lawn as it can get muddy and promote fungi growth on St Augustine. Overwatering also softens the ground, making it easy to damage the lawn.

Step 3: Dethatch Your Lawn

Safe ways of dethatching your lawn include using a hand rake or a mower. Below are descriptions of these two processes.

Using a Hand Rake to Dethatch

Dethatching using a hand rake is effective in small lawns, less than 1,500 square feet, as it’s slow and requires a lot of labor. However, a hand rake is the easiest and safest tool to use on uneven lawns. This tool can reach inaccessible areas where the mower can’t reach.

You should apply short movements when using a hand rake as you repeatedly move it over the turf. Ensure you remove as much thatch as possible, leaving behind about half an inch of turf to promote grass growth. Leaving behind more than this amount will compact and form more thatch.

Using a Mower to Dethatch

Using a mower is the most effective way of dethatching St Augustine. Whatsmore, you can easily rent this tool at the nearest local hardware store if you don’t own one.

Mower’s blades pull massive layers of thatch to the turf’s surface, making it easier to collect. You should set the mower’s blades three inches apart and mow the lawn once to avoid damaging it. Be careful not to go over the same place twice, and remove the thatch from your lawn’s surface using a hand rake.

Never leave the lifted thatch on your lawn, as it will attract pests. You could add it to your compost pit to boost decomposition if you have no place to dispose of the thatch.

When to Dethatch St Augustine

The best time to dethatch St Augustine is during the spring after surpassing the winter dormancy. At this period, the grass is proliferating and is in great need of trimming and dethatching.

Dethatching applies some stress to the grass. Doing it during this period gives it enough time to recover and grow.

Dethatching during the winter or fall is risky, as the grass has a lower chance of recovering and grows at a low rate. Your lawn will end up with patches of dead grass. 

The frequency of dethatching st Augustine is dependent on the variety you have on your lawn. Below are steps to identify if St Augustine is ready to be dethatched.

  • Dig up a section of the lawn three inches deep using a hand shovel
  • Measure the thatch thickness using a tape measure or ruler
  • Your yard is ready for dethatching if the thatch is more than half an inch thick

Precautions To Take When Dethatching St Augustine

The following precautions are vital when dethatching to avoid damaging your lawn.

Never Use a Power Rake

Unlike other turf grasses that grow tall and have underground roots or rhizomes, st Augustine grass only grows up to twelve inches and spreads like stolons; quite delicate. Use gentle tools like a hand rake or mower to dethatch instead of a power rake, which is aggressive and will cause excessive damage to your lawn.

Always Dethatch at the Right Time

You should only dethatch St Augustine during the spring as this period allows the grass enough recovery time. Moreover, this grass grows slowly during the cool seasons; you don’t need to mow or dethatch.

What Should I Do After Dethatching St Augustine Grass?

Follow these tips to ensure your lawn flourishs after dethatching.

Aerate the Lawn

Aerating your lawn after dethatching is quite effective. This is because you have a smaller layer of thatch to struggle with. Moreover, it allows the next layer of thatch that forms to decompose faster. Aeration enables the soil to absorb water and other nutrients quickly, promoting grass growth.

Use a core aerator, as it helps loosen the soil and thus helps speed up the recovery period.

Add Fertilizer to the Lawn

Applying fertilizer to a freshly dethatched lawn has various benefits. It not only speeds recovery and promotes growth but also prevents weed growth. Dethatching allows the fertilizer to penetrate the soil more quickly, which is suitable for the grass.

Adding fertilizer allows st. Augustine grass to bounce back within a few weeks. The grass will also be more vibrant and greener than before dethatching.

Final Thoughts

Dethatching St Augustine grass is effortless and straightforward. Follow the steps and precautions discussed above for the best results. Aeration and fertilizer are essential after dethatching for fast lawn recovery.