How Often Should I Mow My St. Augustine Grass?

As a longtime lawn care enthusiast, one of the most common questions I receive from St. Augustine grass owners is “How often should I mow?” While it may seem straightforward on the surface, determining the optimal mowing frequency for St. Augustine turf actually involves assessing several factors. The growth rate, weather, season, and other elements all play a role in deciding how frequently to cut for a healthy, attractive lawn.

In this article, I’ll share the ins and outs of St. Augustine mowing needs gleaned from years of firsthand experience. You’ll learn how elements like fertilization, rainfall, and time of year impact how quickly this grass grows and needs cutting back. I’ll provide tips on ideal mowing height, equipment, and best practices tailored specifically for St. Augustine. Whether you just planted new sod or plugs or have an established lawn, you’ll have a better understanding of how to adapt your mowing routine.

Proper mowing is essential for any lawn, but the needs of St. Augustine are unique. My goal is to equip you with the expertise required to determine the optimal grass cutting schedule. Let’s get growing!

What Factors Determine St. Augustine Mowing Frequency?

When homeowners ask me “how often should I mow my St. Augustine grass?”, my first response is always “Well, that depends…”. Determining the ideal mowing frequency isn’t as simple as following a set schedule. There are several elements that impact how fast St. Augustine grows and needs cutting.

How Does St. Augustine Growth Rate Affect Mowing?

The most obvious factor is the inherent growth rate of St. Augustine grass. As a vigorous, spreading warm season turfgrass, St. Augustine grows quickly when conditions are optimal. This rapid horizontal growth habit is what allows it to fill in bare spots and form a thick lawn, but it also means more frequent mowing is required.

I tell homeowners to expect to mow established St. Augustine up to twice per week during the active growing season. However, growth rate varies among St. Augustine cultivars. More dwarf, compact varieties like Seville need less frequent mowing than very robust types like Raleigh. Knowing your specific grass type is helpful.

During peak growing times, don’t let St. Augustine get much over 4 inches tall before mowing. Otherwise, the excessive clippings can clump and suffocate the lawn. Staying on top of growth is key.

Does Weather Impact How Often St. Augustine Needs Mowing?

Absolutely! Temperature, sunlight, and rainfall fluctuations all affect the rate of growth for St. Augustine.

In terms of temperature, St. Augustine thrives when daytime highs reach 80-90°F. Cooler temperatures slow growth and mowing needs decrease.

Adequate moisture is also imperative for fast St. Augustine growth and spread. 1-2 inches of weekly rainfall provides optimal mowing conditions. During dry spells, irrigation is needed to maintain growth rate.

Lots of sun fuels the rapid growth of St. Augustine. Shady lawns grow more slowly and won’t need mowing as often. Pay attention to microclimates in your yard.

Does Fertilization Change St. Augustine Mowing Frequency?

Mowing St. Augustine Grass

There’s no question that fertilizing spikes the growth rate of St. Augustine, meaning more frequent mowing. I mow an extra time per week with fertilization.

Use a balanced fertilizer, and only feed St. Augustine when it is actively growing. Excess nitrogen on dormant grass leads to disease issues.

Proper nutrients ensure your St. Augustine has the “fuel” to sustain rapid growth. But be prepared to mow more often if you fertilize regularly.

In summary, St. Augustine mowing plans must adapt to changing conditions week-to-week. Monitor your lawn’s growth patterns and mow as needed to maintain a healthy stand of grass.

Best Practices for Mowing St. Augustine Grass

Now that we’ve covered the factors that impact mowing frequency, let’s discuss some best practices for cutting St. Augustine grass itself. Proper mowing is crucial for the health and appearance of any lawn. Here are my top tips for mowing St. Augustine based on years of experience.

What’s the Ideal Cutting Height for St. Augustine Lawns?

When mowing St. Augustine, aim for a finished cut height of 3-4 inches. This is the “sweet spot” that allows the grass to flourish. Any shorter risks scalping the lawn.

I don’t recommend cutting St. Augustine shorter than 2.5-3 inches, except for dwarf cultivars. This causes excessive stress on the grass.

If dealing with shady areas, allow St. Augustine to grow slightly taller – up to 4 inches. The extra foliage helps compensate for the lower light levels.

Raising the mowing height going into summer helps the grass compete with heat and drought stress as well. Deep roots need ample leaf surface area.

St. Augustine should only be mowed down to 2 inches when overseeded with cool season ryegrass for winter color. The short cut ensures sunlight reaches the ryegrass seedlings.

Should I Mow St. Augustine Based on the 1/3 Rule?

The 1/3 rule is a great guideline for mowing St. Augustine and other lawns. Only cut off 1/3 of the total blade height with each mowing session.

For example, if your target height is 3 inches, mow once the lawn reaches 4.5 inches. Removing no more than 1/3 minimizes stress on the grass.

This rule prevents overcutting and avoids shocking the lawn. Gradually taking off growth is healthier than infrequent drastic cuts.

During peak growing times, you may need to mow St. Augustine every 2-3 days following the 1/3 rule to maintain the preferred height. It’s labor intensive but worth it!

Mowing Methods and Blade Sharpness for St. Augustine

Use a quality rotary or reel mower with sharp blades to cut St. Augustine cleanly without shredding leaf tips.

Dull mower blades tear rather than cut the grass cleanly. This causes the leaf tips to turn yellowish-brown after mowing. Keep blades sharp.

Always mow in different directions to avoid ruts developing over time. Stick to dry conditions as wet grass clumps more easily.

I recommend collecting clippings only if leaving them causes matting issues. Otherwise, use mulching mode to return nutrients to the lawn.

Proper mowing height, techniques, and equipment make all the difference in maintaining healthy St. Augustine grass. Don’t cut corners when it comes to your lawn’s needs.

Adjusting St. Augustine Mowing Based on Season

One of the biggest factors determining mowing needs for St. Augustine is the time of year. St. Augustine growth patterns change significantly between spring, summer, fall and winter. Here are my tips for tailoring your mowing schedule by season:

Early Spring and Fall Mowing Considerations

As temperatures warm in early spring, St. Augustine breaks dormancy and begins actively growing again. But don’t expect summer-like growth rates yet.

Gradually reduce mowing height from the 2-3 inches used in winter back up to the desired 3-4 inches for summer. This allows the lawn to green up.

Early spring growth is sporadic with some weeks faster than others depending on weather fluctuations. Monitor conditions and mow as needed.

Growth remains strong through early fall. But as temperatures cool later in the season, progressively drop St. Augustine height back down for winter.

Mowing frequency decreases during these shoulder seasons. But don’t abandon mowing completely – modified cuts are still beneficial.

Mowing Frequency in Summer for St. Augustine

Expect to mow St. Augustine up to twice per week at the height of summer, depending on your cultivar. Fast growth rates require diligent mowing.

If managing irrigation properly, summer mowing should not taper off due to drought stress. St. Augustine needs about 1-1.5 inches of water per week.

Monitor your lawn closely when temperatures exceed 90°F. Growth may slow if heat stressed, signaling a need to adjust mowing plans.

Cutting during the cooler morning hours helps reduce stress on the grass during intense summer heat. Never scalp the lawn by mowing too short.

Frequent summer mowing is labor intensive but promotes thick, healthy turf. Make sure your mower is serviced and blades are sharp.

How Winter Dormancy Affects St. Augustine Mowing Needs

As St. Augustine enters winter dormancy, mowing needs to become very minimal in warm regions. Cool season grasses are better suited for winter mowing.

Make a final mowing at ~2 inches to neatly trim up St. Augustine before full dormancy. No further cuts are needed until spring greenup.

In colder climates, dormancy may only last a few months before growth resumes. Continue periodic mowing based on grass health.

If overseeded, mow winter ryegrass as needed, but keep St. Augustine height slightly below your summer target until spring.

Adjusting mowing practices based on seasonal needs is key to maintaining healthy St. Augustine grass year-round. Understanding the growth habits of your lawn allows you to plan a proper mowing calendar.


When it comes to mowing St. Augustine grass, there are some common questions that pop up again and again. After years of helping homeowners care for their lawns, these are the topics I get asked about most when it comes to cutting St. Augustine turf:

How Often Should I Mow Newly Planted St. Augustine Sod or Plugs?

With new St. Augustine sod or plugs, wait until the grass is well-rooted before mowing. This takes 10-14 days typically. Mowing too soon risks uprooting the grass while the roots are still shallow.

When the sod has firmly knit into the soil and new growth is visible, do an initial mowing at the highest setting – around 4 inches. Gradually lower to your target height over the next 2-3 mowings as the St. Augustine continues maturing.

Be very gentle the first month, using a push mower if possible. Sharp blades are critical to avoid tearing young leaves. New sod and plugs need TLC as they establish.

Is It Okay to Let St. Augustine Get Slightly Overgrown Between Mowings?

Maintaining a strict mowing schedule can be tough for homeowners. Life happens! But letting St. Augustine grass grow too tall between cuts risks harming the lawn’s health.

As a general rule, never allow established St. Augustine to get more than 1/3 above your target cutting height. For a lawn cut at 3 inches, 4 inches is the max.

Excessive clippings left on the lawn can clump and suffocate the grass rather than decomposing. Tall overgrowth also creates an environment ripe for disease.

Stick as closely as possible to a routine mowing schedule based on your grass growth rate to keep St. Augustine a manageable height. Going too long between cuts does more harm than good.

Can I Mow St. Augustine Less Frequently to Allow it to Thicken Up?

I don’t recommend mowing St. Augustine less often or at a taller height to try accelerating growth. This usually backfires.

Infrequent mowing lets the lawn get puffy and overgrown. Air circulation and light decrease, which thins the turf over time. Disease risk also rises significantly.

A better approach for thicker St. Augustine is proper fertilization, irrigation, and cultivation practices. Mowing frequently maintains optimal density.

Remember, vertical leaf growth is not the goal with St. Augustine. Focus on encouraging aggressive horizontal spread via stolons and rhizomes. Proper mowing facilitates this.

In summary, stick to a routine mowing schedule suited for your grass type and season. Both under- and over-mowing cause problems for St. Augustine health and thickness over time.

In Summary

Properly mowing St. Augustine grass on a routine basis is essential for maintaining a lush, healthy lawn. But determining the optimal mowing frequency isn’t as simple as following a set calendar. Factors like grass growth rate, season, weather conditions, and more all impact when and how often you need to cut your St. Augustine turf.

The key takeaways around mowing St. Augustine include:

  • Monitor your specific lawn’s growth patterns as they change through the seasons
  • Mow frequently during peak growing times, up to twice per week when actively growing
  • Follow the 1/3 rule – only cut 1/3 of total blade height per mowing session
  • Keep mower blades sharp to prevent shredding leaf tips
  • Adjust mowing height and frequency based on weather fluctuations
  • Let new sod or plugs establish deeper roots before starting to mow
  • Never allow St. Augustine to get drastically overgrown between mowings

With a little attentiveness and adaptability, you can dial in the perfect mowing routine to keep your St. Augustine grass thriving year-round. Healthy turf starts from the roots up.

Scroll to Top