How to Make St. Augustine Grass Spread Quickly and Grow Thicker

A thin lawn is not very attractive. If you’re growing impatient with your grass not covering your yard fast enough, this guide will help you make St. Augustine grass spread quickly, grow back,and form a thick cover for a beautiful lawn.

If you want St. Augustine grass to spread faster and grow thicker, plant during summer and make sure you lay down the right type of soil – preferably a well-aerated soil type. Apply phosphorus fertilizer and keep a good watering schedule to help with quicker root and foliage development.

You may also need to kill weeds early enough to prevent competition for nutrients and allow your lawn to grow thicker.

If you’re planning to lay sod or install St. Augustine plugs on your lawn, you’re probably wondering how long you’ll have to wait before the grass spreads and covers the entire lawn with its beautiful, lush green color.

Can You Buy St. Augustine Grass Seed?

Short answer, no. You don’t need to seed a yard with St. Augustine. This grass type comes in plugs or cuts of squares and this is what you will plant in your yards. Using plugs is much cheaper upfront but requires a few weeks of patients while it fills in. Keep on reading to learn how to help it spread out faster and healthier.

Does St. Augustine Grass Spread?

Yes, St. Augustine grass has a dense growth pattern and spreads relatively fast in comparison to most types of warm-season turf-grasses. This fast spread is facilitated by above-ground shoots (stolons).

In addition, the fact that this grass species has good traffic tolerance means that it will still spread at a normal rate even when under use while it still hasn’t fully filled in.

How to Make St. Augustine Grass Spread Faster

How to make st augustine grass spread quickly - thicker

Homeowners that don’t consider sodding as their preferred lawn method of establishing a lawn may have to wait for a bit longer before they have a filled-in, usable lawn.

However- you don’t always have to wait for so long because there’s always something you can do to make St. Augustine grass spread faster and grow thicker.

Here’s what you can do to help your St. Augustine lawn grow and spreads faster to cover your entire lawn:

1. Use the right type of soil

Before planting St. Augustine grass on your lawn, you may want to choose a soil type that best supports the growth and spread of this turfgrass variety. Some soil types (such as waterlogged soil) tend to inhibit the growth of St. Augustine by depleting underground oxygen supply.

For bare spots and uneven areas in your yard, you may need to add some topsoil, as this helps reduce pooling.

  • The best soil for St. Augustine grass is one that is well-drained (like sandy soil) with pH ranges from 5.0 to 8.5. A slightly acidic pH will still be great for faster growth and spreading.
  • For top-dressing a St. Augustine lawn, use either sandy loam soil or clean free-flowing sand. Use no or very little organic material.

If your lawn is growing slowly and remains sparse or thin, the problem could be water-logging. This turfgrass does not grow and spread fast in compacted clay soils.

To find out whether you have the appropriate soil type to facilitate the fast growth of St. Augustine, you can reach out to A&M’s AgriLife soil testing service, They’ll test your soil and brief you on its health and quality. Or pick up a DIY soil test kit and find out what you need to do to your soil to give the perfect environment for your St. Augustine to spread.

2. Stick to the appropriate maintenance schedule

You should ensure to draft and follow a weekly lawn maintenance schedule post-establishment. Effective maintenance comprises watering, fertilization, and mowing. This will speed up the spread of St. Augustine grass.

The appropriate mowing height for St. Augustine grass is 3.5-4 inches. It’s also important to use a high-quality, slow-release fertilizer that will promote St. Augustine’s growth.

Phosphorus-laden fertilizers are great for stimulating grass spread during the first few months post-establishment. Afterward, you can switch to normal nitrogen fertilizer. The appropriate amount is about 0.7lbs of “Nitrogen” per 1,000sqft. Be sure to read and follow the bag rate of your preferred fertilizer.

Proper watering/irrigation is also important.  It entails watering multiple times daily during the first-week post-installation. For the second week, ensure to irrigate your St. Augustine grass sods/plugs up to at least half-an-inch of water.

By the sixth week, you should have scaled back the irrigation frequency to a point whereby you only water the lawn when necessary.

3. Plant St. Augustine grass during summer

Being a warm-season turfgrass, St. Augustine grows best during summer. You should, therefore, establish your lawn in mid-summer when conditions are great for the growth and spread of this grass species all over your lawn.

St. Augustine grass is usually dormant during the colder winter and fall seasons. Growing during these seasons is- thus- not recommended if you want a quick spread.

4. Control weeds effectively

Unwanted weeds within your lawn will compete for important nutrients with your St. Augustine grass. Weed invasion can really hinder the growth and spread of the desired plant species.

It’s crucial to effectively get rid of weeds in your lawn to make St. Augustine spread quickly and grow thicker. Common notorious grass weeds that can slow down the growth and spread of St. Augustine grass include crabgrass, dallisgrass, and most broadleaf weeds.

Also see: How to Remove Crabgrass in Your Lawn Permanently

How long does it take for St. Augustine plugs to spread?

Normally, it takes about 7-14 days for newly installed St. Augustine grass plugs to begin spreading, following firm root establishment in the soil.

Once the rapid growth/spreading starts- however- the amount of time it will take for the bare spots on your lawn to be completely filled in may vary, depending on the plug spacing you choose.

Below, we take a look at the various plug installation spacing methods that will determine how quickly your St. Augustine grass plugs spread.

High-Density Plug Installation

This method requires a 6-11-inch spacing between the sprigs, creating ample room for healthy root development. When the roots are able to tap adequate nutrients from the soil despite such close spacing, your chances of ending up with a fast fill-in are higher.

Typically, you should have a fully-filled, thick lush green lawn within a year if conditions are perfect.

Typical Density Plug Installation

This density choice requires St. Augustine grass plugs to be spaced out about 12-18 inches from each other. With this density, the St. Augustine grass plugs will spread at a slower rate and you’ll have to endure a longer fill-in duration for bare spots on your lawn.

On the upside, it’s more cost-effective compared to high-density plug installation, as you won’t have to use lots of sprigs to cover up your entire lawn.

Low-Density Plug Installation

This option requires a 13-24 inch spacing- and is recommended for lawns that experience low foot traffic since it takes time for the St. Augustine plugs to fully spread out over the entire lawn with such wide spacing.

Typically, it takes well over a year for St. Augustine grass to spread and fully fill in over a regular-sized backyard lawn.

In a nutshell…

Just to recap what’s been discussed – St. Augustine grass is a fast-spreading turfgrass species. However, you can still improve this spread-rate by considering a few aspects. But always start with a soil test so you know how to treat your yard properly for optimal growth.

The rate at which St. Augustine grass spreads depends on various factors including- soil type, lawn maintenance routine, and the time of planting/installation.

Growing St. Augustine Grass - Expert Lawn Care Tips

12 thoughts on “How to Make St. Augustine Grass Spread Quickly and Grow Thicker”

  1. Hi saw your video I have st. Augustine sod for about 3 weeks.
    Wondering when and which brand I should get for fertilizer?
    Also, can I add grass seed to the more barren areas? If so, which type do you recommend…is St. Augustine grass seed available?
    It’s doing ok living in Florida it’s really the only grass that does well although I prefer the softer grass.
    For now, I light-water 2 times per week
    Thanks in advance for taking the time to answer my questions.
    Judy Kirshner

    • Just, try Sunniland out of Sanford. Most Lowe’s carry their products. I suggest the white bags labeled Sunnlind Professional. Don’t let the label detour you off as it’s specifically tailored for Florida climate. Go to sunnilands website they have all their products broken down.

  2. No seeds available for st.augustine. only sod and plugs.

  3. Hello. I have an area of roughly 500 sq ft where the St. Augustine runners are dry and visible.
    Can I lay topsoil over that area to encourage the healthy st. Augustine to spread where the runners have dried?
    Thanks in advance for your advice

  4. Trying to put the right soil down to add on St. Aug grass has been difficult to say the least. Most stores carry this composite stuff (not real dirt) and I have spread it over my lawn which is not responding to running. How do I remove and add real dirt? Any suggestions on which brands to purchase at Lowe’s or Homedepot?

  5. Sod layed in January. Established well but due to overwatering, got fungus. I applied Immunox PlusI noticed that the blades are thin, it’s a thin lawn but evenly thin except for the fungus. Can you tell me what to throw down on it to get, like you said, for it to get bigger blades, thick and spreading? I was using cornmeal but didn’t do much. Literally, can you tell me the brand and ratio to get or a link? I only have 150 square foot townhome but other neighbors it’s dark green (nitrogen?) and thick like a carpet and erect and their sod was layed down same as mine. Fungus just in a few spots but I treated the entire lawn. What’s next?? Thanks you!!!!

  6. Jeff Messing, check out YouTube channel for Lawn Care Nut Allyn Hane. He discusses using 2 different types of fungicides at same time to battle lawn problems with better results than just using one type. There is a code on product labels and he says to look for type 3 and type 11. His channel is a treasure trove of all kinds of advice.

  7. I have some areas that are very dense some bare spots in other areas. What size plugs should i dig up to plug the bare areas?

    • If you do around 2-3″ plugs you should be good to fill in those bare spots. I’ve done that plenty of times for neighbors.

  8. I have weeds galore in my front yard, and in my back it’s mostly dirt with weed and some grass. My side has a good healthy amount of st Augustine. Where should I start? Should I just plant now and kill weeds after or kill weeds now and then plant?

    • Hey Sean, thanks for writing in. I would give it a good dose of Tenacity to take care of the weeds first and the lay down new sod. If you want sod delivered straight to you, take a look at SodSolutions here I’ve been workin’ with these guys lately and impressed on their sod selections, price, and how they get it delivered to you.


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