5 Tips on How to Keep your St. Augustine Grass Healthy and Fresh in Florida

Kenneth Wilson

When I first moved into my home in Florida, I had no idea how to take care of my lawn since I didn’t have to do it back in Vermont. It was surprising to find out that there were different types of grasses. After learning that I have St. Augustine Grass, I gathered more information about it. 

St. Augustine grass or Stenotaphrum secundatum is a common type of grass found in tropical and subtropical areas. This warm-season lawn grass has a dark green or bluish-green color which makes it look like a new lawn when it’s well-maintained. It forms a dense and carpet-like sod which efficiently crowds out weeds and other grasses.

It grows in different types of soils and pH levels, but it does best in rich and well-drained soil. Aside from these factors, it is also a popular lawn grass in Florida because it thrives in a warm and humid climate.

If you are planning to get this grass or already have it, you should know it requires medium to high maintenance. Here are some tips on how to keep St. Augustine Grass healthy and looking lush.

Proper Irrigation

Once your St. Augustine is established, you will only need to water it as needed. This grass can survive without rainfall or irrigation for a long time. But frequently apply water when you have sandy soil or if the blades become a bluish-gray color, curled, wilted, folds, or shows footprints when walked on.

It is also important not to overwater. Three-quarters to one-inch of water is fine and then just add one-fourth inch during the summer. Make sure to water the soil to a depth of 3 to 4 inches to keep it healthy.

This is an important step since proper irrigation will also help prevent or reduce pests and diseases.

  • It’s best to water your lawn is early in the morning.
  • Clay soils take in the water slowly.
  • Don’t forget to check your local water restrictions.

Know When and How Short to Mow

Bring out lawnmower in spring but never during the winter months (except for southern regions in South Florida). 

When it’s March to May and the grass starts turning green, then you can mow it. If it’s brown, don’t try to mow it even if it looks hideous. It’s not a good idea to use lawn mower on dead or dry grass before its active growing season because St. Augustine spreads by stems or stolons above ground. Mowing it low may damage and scalp the grass and discourage deep rooting.

The best height for St. Augustine grass is at 3.5 to 4 inches. Mow it above this height since shortening it too much will make it look less green. If cut at the proper height, it will prevent thatch and grass clippings from building up. Don’t worry about collecting grass unless if the removed grass is in clumps.

  • Avoid mowing your lawn when it is stressed due to drought or extremely hot weather.
  • Use sharp blades for a clean cut since dull blades will shred and make your grass look light brown.

Don’t forget to fertilize

Before we discuss how to properly fertilize your lawn, you should first test it. Get your soil tested at least once every two to three years.

This video shows you how to test your soil using a test kit. After finding out the results, you’ll have a better idea of what nutrients your soil needs. 

For fertilizing, it is advised to apply one pound of nitrogen for every 1,000 square feet, three weeks after the grass starts turning green. You can also use this calculator to help you determine the amount of fertilizer you will need to apply. It’s recommended to fertilize for two to six times a year.
  • Make sure not to apply more than five pounds of nitrogen for every 1,000 square feet in a year.
  • Overfertilization will cause thatch and pest and disease problems.

Controlling and Removing Weeds

One of the annoying things you’ll have to deal with is weeds ruining your lawn. But before you apply anything, you have to know that there are pre-emergent and post-emergent herbicides.

Before they start growing, you should apply pre-emergent herbicides specifically made for St. Augustine grass during the start of spring or earlier for warmer regions. But once you see that weeds are growing, this chemical won’t do any good.

When this happens, you’ll have to use post-emergent herbicides. Find one that is labeled for St. Augustine grass and make sure not to apply this chemical when the turf is under stress.

  • Apply herbicide with caution and read the instructions. 
  • You also shouldn’t start treatment or apply any chemical if you haven’t properly identified the weed.

Handling Common Pests and Diseases

I’ll warn you right now - it’s common to find brown grass or brown patch fungus during the spring and fall. It happens because of the warm weather and humidity, combined with over-application of nitrogen. You should also watch out for large patch, take-all root rot, bare spots, or grey leaf spot disease.

Here’s a video showing what a grey leaf spot disease looks likes. It tends to appear in areas that are damp, shady, low-lying, or where water runoff flows regularly. This will ultimately cause your turf to get thinner. 

You will need fungicides to stop these diseases from spreading. But before you resort to chemicals, you can prevent this by reducing irrigation and nitrogen, improving drainage, and provide better air movement through the soil.

For the pests, your number one problem is chinch bugs. They cause yellow spots or dryness under sunny areas. There are two ways you can check for chinch bugs.

First, you can manually check the turf for chinch bugs activity with a magnifying glass since these pests are small. Another way is the float test, where you use a coffee metal can with the top and bottom removed. Push this can into the possible affected area then fill it water. If there’s any, you’ll see these bugs float. Use an insecticide or hire a professional to treat your lawn when these pests are present.

Aside from chinch bugs, you should also watch out for lawn grub worm. You can check for these by seeing if you can easily pull out the grass of the potentially affected area. They are also larger and easier to see in the soil. You may use a pesticide to remove grub worms and other pests.

  • You can avoid most pests and diseases by properly irrigating and fertilizing your lawn.
  • Don’t apply too much nitrogen on shaded areas during the summer.
  • Avoid irrigating in the evening. 
  • Make sure to remove grass clippings in problem areas.
Kenneth Wilson
October 10, 2019
2terra, Yard & Garden

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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