St Augustine Maintenance Schedule

Putting together a St Augustine grass maintenance schedule will help you keep your lawn healthy and looking its best all through the growing season. This lawn care guide provides a general overview for you to follow. You might also benefit from reading our specific articles on Watering, Fertilizing and Mowing your St Augustine lawn.

Spring Maintenance for St Augustine Grass
How you care for your St Augustine grass from March through May sets the tone for the entire growing season. There are several keys to getting off on the right foot once winter is gone and things begin to green up.

Start by cutting the grass to 3”. Some types of St Augustine grass, such as Palmetto and Mercedes can be mowed as short as 2”. A fresh cut the first thing in the spring removes some of the old tissue and stimulates growth. Next, apply a complete Nitrogen-Phosphorous-Potassium fertilizer, also known as an N-P-K fertilizer in a 4-1-2 or 3-1-2 ratio. A good choice is 16-4-8. Apply 3 pound of 16-4-8 to every 1,000 square feet of lawn.

If weeds are a problem, use pre-emergence herbicide when the forsythia is in bloom. Later, in May, apply a post-emergence herbicide to control broadleaf weeds. Only use products that are suitable to St Augustine grass, which should be indicated on the label.

For watering, wait until the grass starts to show some wilt. When a third of the leaves are stressed, get out the sprinkler. The average amount of water your lawn needs is 1 inch per week. Lawns with sandy soil require slightly more, with more frequent watering. Soils with heavy clay should be watered less frequently, giving the moisture time to sink into the soil without running off or evaporating.

If you’ve got more than ½” of thatch, May is a good time to dethatch your lawn. Rent a dethatcher or hire a local lawn care company to do it. Irrigate the lawn with ½” to 1” of water after dethatching.

Paying attention to these details in the spring makes the maintenance schedule much easier throughout the rest of the year.

Summer Maintenance for St Augustine Grass
Mow frequently and keep your grass at its preferred height of 2” to 3”, depending on the variety. Fertilize with a slow-release formula, adding about 4 pound of 16-4-8 fertilizer per 1,000 square feet every 4-6 weeks.

Use the same rule for watering the grass. Wait until it’s looking slightly stressed and then irrigate with 1” of water. St Augustine grass suffers more from too much water, a cause of disease, than too little, so don’t add water until the lawn shows you it needs the moisture. If weeds appear, use a post-emergence herbicide and follow directions closely.

Fall Maintenance for St Augustine Grass
In September through November, you will transition from maintaining a growing lawn to preparing it for winter. Start by raising the mowing height by ½” so the lawn has a little more bulk to tolerate the harshness of winter.

You may need to water less often as the weather cools and it rains more frequently. Use a rain gauge to determine if your lawn has had its inch of rain for the week.

Don’t fertilize with Nitrogen after September 1. If a soil test shows a lack of Potassium, fertilize with muriate of potash (0-0-60) or potassium sulfate (0-0-50). As always, follow the label instructions for best results.

Winter Maintenance for St Augustine Grass
After the first frost, retire the mower for the winter. If the weather is very dry, add about ½” per week. Be careful not to add too much because winter is a time that excess moisture can cause rot and disease. If you see weeds cropping up, apply a broadleaf herbicide per directions on the label.

It takes a season or two to get really comfortable with maintaining a St. Augustine grass lawn, or any lawn for that matter. Once you get comfortable with the schedule, you’ll probably even find yard work and its results to be very enjoyable. The St Augustine grass will reward the TLC you give it by staying green and healthy throughout the growing season. It will bounce back in early spring to provide a beautiful, comfortable carpet for all your outdoor activities.


  1. Any brand suggestion who accomplishes your amounts suggestions on fertilizing each season?
    Thank you, resoectfully, William.

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