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How to Care for St. Augustine Grass

Bert spent 25 years working as a home-improvement and residential construction contractor in central Florida.

Many Southern homeowners choose St. Augustine grass as their lawn covering because of its ability to thrive in tropical and sub-tropical climates. St. Augustine grass (Stenotaphrum secundatum) spreads with stolons, often called runners, using a process called vegetative propagation. Each stolon forms its own root ball and blade set. The stolons weave together, forming a thick, carpet-like ground cover. Following a maintenance schedule keeps a St. Augustine lawn looking lush and deep green for many years.

As a warm weather turf grass, St. Augustine grass flourishes in many parts of the southern United States.

As a warm weather turf grass, St. Augustine grass flourishes in many parts of the southern United States.

St. Augustine Grass Types

Homeowners have several different types of St. Augustine grass to choose from. Some cultivars offer increased insect and shade tolerance. Homeowners should carefully match their yard's characteristics with the St. Augustine type's requirements. Popular cultivars include the following.

  • Floratam: The most purchased turf grass in Florida and most popular throughout the gulf coast region. Floratam needs five to six hours of sun per day, but it grows best in full sun. Homeowners with shady yards should consider other cultivars or ground covers. Set the lawnmower's cut height between three and four inches.
  • Palmetto: Palmetto prefers full sun, but grows in partly shady areas. Its drought tolerance makes it a candidate for homeowners with local watering restrictions. Set the lawnmower height to approximately three inches.
  • Seville: Considered a semi-dwarf grass, homeowners with Seville St. Augustine grass should set the lawnmower's cut height at two inches. Seville grows well in yards with shady areas. Regular insecticide applications help prevent chinch bug and webworm damage.
  • Captiva: Known as a chinch bug-resistant St. Augustine grass, Captiva requires one-third less mowing than its Floratam cousin due to its slow growing nature. Captiva also performs reasonably well in shady yards. Set the lawnmower's blade height to about 2.5 inches.
Use a broadcast spreader to apply lawn fertilizer, fungicide and insecticide.

Use a broadcast spreader to apply lawn fertilizer, fungicide and insecticide.

Fertilizer Tips

Healthy St.Augustine lawns like regular fertilizer applications. A typical fertilizer schedule sets the first feeding at the start of the growing season with a "Weed and Feed" fertilizer and then spaces the remaining doses with a temperature-appropriate lawn food. When creating a personalized schedule, always follow any local fertilizer restrictions. Some locals prohibit summertime fertilizer applications.

Homeowners typically choose either a liquid or granular lawn fertilizer. Grass absorbs liquid fertilizer quickly and the results appear within a few days. A liquid fertilizer dispenser attaches directly to a hose. Simply turn the hose on full and spray the turf in long slow strokes. Apply enough the wet the grass to the roots. This method does not take much time or effort, however, it is hard to soak the grass evenly down to the roots and the excess fertilizer mixture either puddles in isolated areas or runs off.

A mechanical spreader applies granular fertilizer at a set rate and throws the particles evenly. Pay attention to and do not exceed the manufacturer's recommended application rate. Push the spreader across the lawn in a similar pattern as the lawnmower. Apply the fertilizer in the morning and thoroughly water the lawn. Do not over water and create runoff. The lawn only absorbs a certain amount of fertilizer; the rest has the potential to wash away and become a groundwater pollutant.

The three numbers listed on a bag of fertilizer represent the nitrogen, phosphorus, and potassium percentages. To help understand these numbers, remember "up, down and all around." Basically, the first number helps the part of the plant above ground, the second number promotes below-ground root growth and the third number helps all parts of the plant. St. Augustine lawns like fertilizers with a high nitrogen content during the growing season and a more balanced fertilizer throughout the rest of the year.

Even a healthy lawn can have a hard time withstanding the harsh summer heat. Giving St. Augustine grass an iron supplement during the summer helps turn a yellowish looking lawn green. Stay on the lighter end of the manufacturer's recommended dosage. With iron, a little bit truly goes a long ways. Wash any iron supplement runoff immediately off of a concrete driveway and sidewalk before it dries.

Use an insecticide as soon as pests appear, typically in the late spring or early summer.

Use an insecticide as soon as pests appear, typically in the late spring or early summer.

Tips for Managing Pests

Many insects thrive in St Augustine grass. Their little communities munch away night and day; enjoying life one bite at a time. Some insects that damage the turf include sod webworms, mole crickets, chinch bugs, and grubs. Damaged areas often initially appear as irregular shaped yellow or brown areas that fail to respond to watering or fertilizer. Sod webworms show up as moths that flutter around your legs while walking across the lawn.

Fortunately a healthy lawn kept on a routine maintenance schedule outgrows light insect damage and St. Augustine runners will quickly fill in treated areas. A trip to the local garden center reveals many different general-purpose insecticides. They all work. Following the manufacturer's recommended application rate and schedule matters more than the actual name on the bag. A highly infested lawn may require a specialized insecticide application before starting routine general-purpose insecticide treatments. Apply a second dose after waiting the suggested amount of time, then start the regular treatments.

Pests such as moles and armadillos dig for and eat many insects. These pests leave small piles of dirt or soft tunnels that collapse when stepped on. The digging disturbs the lawn's root system. Controlling these pests often requires a two-part solution. Spray an animal repellent to persuade the pest to relocate and apply an insecticide to kill their food.

Applying a feed-and-feed type of lawn fertilizer kills weeds and promotes new growth.

Applying a feed-and-feed type of lawn fertilizer kills weeds and promotes new growth.

Tips for Managing Weeds

A healthy, properly maintained St. Augustine lawn typically crowds out weeds and other grasses. The presence of a large amount of weeds in a mature lawn often indicates some type of weakness, such as improper watering, fertilizing, insects, or disease.

Only spread weed killers compatible with this grass and follow the manufacturer's recommended rate of application. Many professionals broadcast a St. Augustine-safe weed-and-feed type fertilizer during the spring and spot treat weeds during the other times of the year. Homeowners with a year-round growing season sometimes apply a second weed-and-feed dose in the fall after the temperatures start to drop. Treat crabgrass with a pre-emergent herbicide during the cool season months.

Spring Care

Increase the watering rate to two times per week as the weather warms. Begin the mowing cycle when the lawn starts to come out of dormancy. Do not bag the clippings. Instead, let them settle to the turf and decompose. The clippings turn into a slow-release organic fertilizer that returns nutrients to the soil.

Start the yearly fertilizer schedule with a "weed and feed" fertilizer in the early spring, about two to three weeks after the lawn starts to turn green. It is better to apply a little late than a little early. Only use a weed and feed fertilizer designed specifically for St. Augustine grass. Other types may burn or kill it.

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Watering a lawn during its growing season keeps it healthy and vibrant.

Watering a lawn during its growing season keeps it healthy and vibrant.

Summer Care

During the summer months, a mature St. Augustine lawn requires water two to four times per week, depending on the soil's makeup and its ability to hold moisture. For instance, sandy soil drains faster and holds less nutrients than more dense soils. Avoid watering late in the afternoon or evening, as it promotes lawn fungus and diseases.

Apply a lawn fertilizer about 8 to 10 weeks after the spring application. Then give the lawn an iron supplement 8 to 10 weeks after the fertilizer treatment. The iron supplement helps green up a healthy but pale-looking lawn. A spray-on iron supplement shows results in a few days.

Avoid herbicides when the temperature rises above 90 degrees. These chemicals damage heat-stressed lawns. When hand-pulling weeds, grip the weed stem near the soil and pull the root with the foliage.

Brown or dead patches often indicate either a pest or fungus infestation. Fungus typically spreads outward from the center with a uniform border, while pest damage often looks more spotty and irregular from a distance. Carefully inspect the edge of the damaged area, looking for insects or brown leaf spots. Apply either a fungicide or insecticide as soon as the first symptoms appear. Some manufacturers make products that treat both fungus and pests.

Autumn Care

Consider the autumn months a transitional period for St. Augustine turf grasses. Warm season grasses start to loose their vibrancy as the growth-promoting long days and warm temperatures of summer gives way. Apply either an autumn blend or winterizing lawn fertilizer in early fall. These fertilizer types contain a more balanced nutrient blend than standard lawn fertilizer.

Cut the watering schedule back to one to two times per week as the local weather dictates. The mowing schedule also transitions to a less intensive rate. Kill cool-season weeds with a St. Augustine-safe herbicide before they mature.

Winter Care

As a warm climate grass, St. Augustine varieties go into dormancy when average the soil temperature drops below 68 degrees. The leaf blades in a dormant lawn lose their pigment and they eventually start to brown. When the average soil temperature reaches 68 degrees the grass starts to come out of dormancy.

During this time of year lower the watering and mowing schedules to one to two times per month, depending on the average daily temperature. Only homes in southern zones where the turf does not go dormant require fertilizer and these homeowners should use a low-nitrogen winterizing fertilizer. To prevent new crabgrass, apply a pre-emergent herbicide once the average daily temperature rises above 65 degrees.

Use sod plugs to fill in bare spots.

Use sod plugs to fill in bare spots.

New Lawn Care

Prior to laying St. Augustine sod, rake or till the bare turf until the surface becomes loose and fluffy. Fill in any low spots with either top soil or a lawn soil. Lawn soil, a light-weight specialized soil, contains a fertilizer blend designed specifically for new lawns. Lay the sod or spread the plugs about.

Fertilize new grass with a slow-release starter fertilizer. This type of fertilizer promotes root growth. Never use a "weed & feed" type of fertilizer on new lawns until its' root system becomes well established. This type of fertilizer contains herbicides which, when applied too heavily, injures the new sod's delicate ends.

Water a new St. Augustine lawn two times per day for the first three weeks, then cut back to a normal seasonal schedule. Turn the water on early in the morning and again in the early afternoon. Use enough water to keep the root system wet, but do not flood the turf. The second watering should start before the turf becomes arid and end before nightfall, limiting the new growth's susceptibility to disease or fungus.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: What insecticide do you use for St. Augustine grass?

Answer: I am not brand loyal. This year I used Bug B Gone. I like to broadcast a granular insecticide with a spreader.

Question: What do you recommend to get rid of mole crickets from a lawn?

Answer: I spread a granular form all-purpose lawn pesticide about 3 times a year. There are products specifically for mole crickets, however I have always had good luck simply using a generic pesticide that kills all the bugs. I normally switch brands every time I need to buy a new bag. Last time I used Spectracide.

Question: What height do I cut St. Augustine Grass?

Answer: The perfect height really depends on the St. Augustine cultivar, however, you will be safe setting the blade at three inches.

Question: How long after laying new sod for St. Augustine grass do I need to wait until it’s first cut?

Answer: It really depends on the amount of sunlight the sod gets and the time of year it is planted. Normally sod planted in full sun during the summer can be cut after 2 to 3 weeks, while sod placed in a shady area during the winter will likely remain dormant until spring. Do not mow until the roots establish and the runners have started to spread.

Question: How long after laying new sod do I need to wait before spreading glandular insecticide?

Answer: I would wait until the roots start to become established.

© 2018 Bert Holopaw

Comments

help me on July 01, 2018:

I was told its to hot for weed and feed. is this true

Bert Holopaw (author) from Central Florida on May 20, 2018:

It is a very popular ground covering here in Florida too.

Susan Brown on May 11, 2018:

I have St Augustine here in Arkansas. I put weed and feed on once every year or two. My lawn looks like a carpet. It doesn't tolerate extended dry spells, but a bit of water takes care of that. Plus the birds love it when I run the sprinkler.

Louise Powles from Norfolk, England on February 16, 2018:

I've never heard of this kind of grass before. But there's a lot of good advice here on how to look after it.

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