Does St. Augustine Grass Go Dormant in Florida?

The Short Answer: Yes — But It Depends on Where You Live

Here’s the deal. St. Augustine grass (Stenotaphrum secundatum) is a warm-season turfgrass. It evolved along the subtropical coastlines of the Gulf of Mexico and the Mediterranean, where winter is more of a suggestion than a season. It thrives when temperatures sit between 80°F and 95°F, and it starts slowing down meaningfully once things cool off.

But “going dormant” isn’t an on/off switch, and Florida isn’t one climate. Whether your lawn actually enters full winter dormancy depends almost entirely on your location within the state, your soil temperatures, and which cultivar you’re growing.

Let’s break the whole thing down.

What Is Dormancy, Exactly?

Before we get into the Florida-specific details, it helps to understand what dormancy actually means from a plant science perspective.

Dormancy is a survival mechanism. When soil temperatures drop below the range where St. Augustine can efficiently photosynthesize and grow, the grass essentially redirects its energy. It stops producing new leaf tissue, slows metabolic processes, and conserves its stored carbohydrate reserves in the stolons and root system. The above-ground blades lose their chlorophyll and turn brown or tan — which is why your lawn looks dead even though the plant is very much alive underground.

Think of it like hibernation for grass. The plant isn’t growing, but it’s not gone. It’s waiting.

The critical distinction: dormant grass comes back. Dead grass doesn’t. This matters a lot in January when you’re trying to decide whether to call a sod company or just wait it out.

The Temperature Triggers

St. Augustine grass doesn’t go dormant because of a calendar date. It responds to temperature — specifically, soil temperature.

Here’s the general science:

Temperature Marker	What Happens
80–95°F (air)	Peak growth zone. This is where St. Augustine is happiest.
Below 65°F (air)	Growth begins slowing noticeably. Color may fade.
Below 55°F (soil)	The grass enters dormancy. Growth essentially stops. Blades turn brown.
Below 50°F (air), sustained	Full dormancy. No active growth above ground.
Below 25°F (air), prolonged	Risk of cold injury or winter-kill, especially for cold-sensitive cultivars like Floratam.

The soil temperature piece is important because soil holds heat longer than air. Your lawn might survive a few chilly nights without going dormant — it’s the sustained, consistent cooling of the ground that flips the switch. According to turfgrass researchers at Texas A&M, St. Augustine typically won’t enter true dormancy until air temperatures stay consistently below 80°F and soil temperatures drop below 55°F.

This is why you’ll sometimes see your St. Augustine still green near your house foundation, along south-facing fence lines, or under tree canopies, even when the rest of the yard has browned out. Those microclimates keep the soil warmer, and the grass responds accordingly.

Florida’s Three Dormancy Zones

Florida runs about 450 miles from Pensacola to Key West. That’s a massive climate gradient, and it means dormancy behavior varies dramatically depending on where you are. The University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) breaks it down into three practical regions.

North Florida (Jacksonville, Tallahassee, Pensacola, the Panhandle)

Expect full winter dormancy.

North Florida gets real winter weather. Temperatures regularly dip into the 30s and 40s from December through February, and hard freezes aren’t uncommon. Soil temperatures drop well below 55°F for extended periods.

Up here, your St. Augustine lawn will go fully dormant. It will turn brown, it will stop growing, and it will stay that way until soil temperatures consistently climb back above 55–60°F in the spring — typically somewhere between mid-March and mid-April.

This is normal. This is healthy. Don’t panic.

The I-4 corridor (roughly the line from Tampa to Orlando to Daytona Beach) is often used as the informal dividing line. If you live north of I-4, plan on your lawn going dormant most winters.

Central Florida (Tampa, Orlando, Lakeland, Daytona)

Expect partial or intermittent dormancy.

Central Florida sits in a transition zone. Some winters are mild enough that St. Augustine grass barely slows down. Other years, a cold snap will send the lawn fully brown for a few weeks before it bounces back.

You might see patchy dormancy — sections of the yard that brown out while other areas (especially near structures or pavement that radiate heat) stay green. The lawn might slow to a crawl rather than fully shutting down.

This is the zone where homeowners get confused the most. The lawn looks bad enough to worry about, but not uniformly brown enough to obviously be “just dormant.” More on diagnosing this below.

South Florida (West Palm Beach, Fort Lauderdale, Miami, Naples, the Keys)

Dormancy is unlikely. But winter stress is real.

South Florida’s soil temperatures rarely drop below 60°F for any meaningful duration. In most years, St. Augustine grass in South Florida stays green and continues growing — albeit more slowly — throughout the winter months.

But here’s the catch that trips up a lot of South Florida homeowners: your grass can still look rough in winter even if it never goes dormant. Shorter days mean less photosynthesis. Cooler nighttime temps slow nutrient uptake. If you’ve been running a low-nitrogen program, the lawn may develop scattered brown blades, thin out in spots, or lose that deep green color.

This isn’t dormancy. It’s winter stress on a grass plant that’s still metabolically active but not getting enough fuel. And the fix is different than what you’d do for a dormant lawn up north.

Dormancy Behavior by Region: Quick Reference

Region	Typical Dormancy	Duration	Green-Up Timing
North Florida	Full dormancy most winters	Dec–Mar (8–14 weeks)	Mid-March to mid-April
Central Florida	Partial/intermittent	Jan–Feb (2–6 weeks, varies)	Late February to March
South Florida	Rare to none	N/A	Year-round growth (slowed)

When the Rules Get Broken: Freeze Events and Cold Snaps

Everything above describes what happens in a typical Florida winter. But every few years, Florida gets a reminder that Mother Nature doesn’t read regional averages.

Case in point: the arctic blast that hit the entire state the first weekend of February 2026 — just last week as of this writing. An arctic air mass plunged into the Sunshine State and delivered the coldest temperatures South Florida had seen in over 15 years. Miami dropped to 35°F, its lowest reading since 2010. Inland areas of Miami-Dade recorded lows around 30°F. Wind chills across the metro area fell into the mid-20s, and areas near Lake Okeechobee felt temps in the teens and low 20s. The National Weather Service issued freeze warnings for inland Broward and Miami-Dade — counties where freeze warnings are genuinely rare.

Farther north, it was even more extreme. Tampa saw snow flurries. Orlando dipped into the 20s. Jacksonville and Tallahassee challenged daily record lows. The NWS reported that, with wind chill factored in, there wasn’t a single city in Florida outside the Keys that stayed above freezing that weekend.

What This Means for Your St. Augustine

Events like this are precisely when the “South Florida lawns don’t go dormant” rule breaks down. When temperatures plunge into the low 30s — or below — even in Broward and Miami-Dade, St. Augustine grass will respond. Here’s the progression you’ll typically see after a hard freeze event:

Immediate (24–72 hours): Blades turn purple to black as cell tissue freezes and ruptures. This is frost burn — ice crystals forming inside the leaf cells and physically tearing them apart. The lawn looks scorched, waterlogged, or wilted.

Short-term (1–2 weeks): Damaged blades dry out and turn brown or straw-colored. The lawn may look uniformly dead, especially in open, exposed areas. Protected spots near buildings, under trees, and along south-facing walls will typically show less damage.

Recovery (3–6+ weeks): If the root system and stolons survived, new green growth will emerge from the nodes once soil temperatures stabilize above 55–60°F. The timeline depends heavily on how long freezing conditions lasted, how deep the cold penetrated the soil, and whether the lawn was healthy going into the event.

Critical Post-Freeze Mistakes to Avoid

The single biggest mistake homeowners make after a freeze event is panicking and doing too much too fast. Here’s what not to do:

Don’t fertilize. The grass can’t use it right now, and pushing new growth too early leaves the lawn vulnerable to another cold snap. Wait until consistent warm weather returns and you see active growth before feeding. For South Florida, that might be a matter of weeks. For Central and North Florida, it could be spring.

Don’t mow. There’s nothing to cut, and mowing frozen or frost-damaged turf creates open wounds the plant can’t heal while it’s stressed.

Don’t rip out brown grass. What looks dead on the surface may still have viable roots and stolons underground. Give it time — at least three to four weeks of warm weather — before making any decisions about replacement. The dead leaf tissue actually provides some insulation for the crown and root zone if another cold night hits.

Don’t overwater. Cold-stressed St. Augustine is highly susceptible to fungal issues, especially large patch (Rhizoctonia solani). Keep irrigation minimal until you see recovery.

The Cultivar Factor in Freeze Events

This is where cultivar selection really shows its hand. Floratam — by far the most widely planted St. Augustine in Florida — is notably cold-sensitive. It can suffer permanent damage or winter-kill at temperatures below about 25°F, especially if those temperatures are sustained for multiple hours. During events like the February 2026 freeze, Floratam lawns in exposed areas are the ones most likely to show significant damage.

Cold-hardy cultivars like Palmetto, CitraBlue, and Raleigh hold up considerably better. If you’re in Central Florida or northern parts of South Florida and keep experiencing freeze damage, it may be worth considering a cultivar switch the next time you install new sod.

How Often Do These Events Happen?

Not frequently — but often enough to matter. Before this past week’s event, the last comparable cold snap in South Florida was January 2010, when a 12-day cold episode broke records dating back to at least 1940. Before that, the benchmark was 1989. So roughly once every 10–15 years, South Florida gets a freeze event significant enough to shock-dormant St. Augustine grass that would otherwise stay green all winter.

For North and Central Florida, hard freezes are more routine — which is precisely why your lawn already enters dormancy naturally as an adaptation. The grass expects it. It’s the South Florida lawns, accustomed to year-round warmth, that get caught off guard.

How to Tell If Your St. Augustine Is Dormant or Dead

This is the million-dollar question. Brown grass in January could mean your lawn is napping — or it could mean you’ve got a serious problem. Here’s how to tell the difference.

The Tug Test

Grab a small section of brown grass and give it a firm tug. If it resists and you can see white or light-colored roots when you pull up a stolon, the plant is alive. Dormant grass holds on tight because the root system is still intact and functioning.

If the grass pulls up easily with no resistance — like pulling hair off a wig — and the roots look dark, mushy, or nonexistent, the plant is dead.

The Pattern Test

Dormant St. Augustine tends to brown out in a somewhat patchy, irregular pattern. Areas with more sun exposure or less insulation from nearby structures will go dormant first. You’ll often see a gradient from brown (exposed areas) to green (protected areas near buildings, under trees).

Dead grass from disease, insects, or drought tends to create more distinct, irregular patches with sharply defined borders — especially if chinch bugs or grubs are involved.

The Timeline Test

If your lawn browned out gradually as temperatures dropped in late November and December, that’s dormancy following its natural trigger. If it browned out suddenly in the middle of summer or fall, something else is going on — likely disease (large patch/brown patch is a major offender) or insect damage.

Check for Grubs

Before you assume dormancy, get down on your hands and knees and look. Peel back some of the brown turf and check for white, C-shaped grubs in the soil. Grub damage can mimic dormancy appearance, and missing this can cost you the lawn.

Cultivar Matters: Cold Hardiness Varies

Not all St. Augustine grass handles cold the same way. The cultivar growing in your yard significantly affects how early it goes dormant, how well it survives winter, and how quickly it greens up in spring.

Cultivar	Cold Hardiness	Notes
Palmetto	Good	Semi-dwarf with solid cold tolerance. One of the better performers in Central FL winters.
CitraBlue	Good	Developed by UF/IFAS. Handles cooler temps well and uses about 25% less nitrogen than traditional varieties.
Raleigh	Excellent	The gold standard for cold hardiness in St. Augustine. Developed specifically for the northern edge of the species’ range.
Bitterblue	Good	Fine-textured with solid cold and shade tolerance. An older cultivar that’s been reliable for decades.
Floratam	Poor	The most widely planted St. Augustine in Florida — but notably cold-sensitive. Prone to winter-kill during hard freezes. Not ideal for North Florida.
Seville	Poor	Fine-textured dwarf variety. Cold sensitive. Best suited for South Florida.

If you’re in North or Central Florida and growing Floratam, you may experience more dramatic dormancy and slower spring recovery compared to a cold-hardy cultivar like Palmetto or CitraBlue. In extreme cold events, Floratam can suffer actual winter-kill — where portions of the lawn don’t come back at all.

What to Do During Dormancy

If your lawn has gone dormant, here’s the playbook.

Watering

Dormant grass still needs some water. The root system is alive and can dehydrate, especially during dry Florida winters. Water your dormant lawn about once every two weeks with roughly an inch of water — unless rainfall is handling it for you. Only irrigate when temperatures are above 40°F to avoid ice formation on the turf.

Mowing

Stop mowing, or at least dramatically reduce frequency. Dormant grass isn’t growing, so there’s nothing to cut. Mowing dormant St. Augustine can actually injure it — the cut tips of the blades are essentially open wounds that won’t heal until the plant resumes active growth. If you mow right before dormancy, keep the height at 3.5 to 4 inches to provide some insulation.

Fertilizing

Do not fertilize dormant St. Augustine grass. The plant can’t take up or use nutrients while dormant, so you’d be wasting product and potentially feeding winter weeds instead. In North and Central Florida, the last nitrogen application should go down no later than mid-September to early October — roughly four to six weeks before the first expected frost.

For more on seasonal timing, check out our full guide on when to fertilize your lawn in Florida.

Weed Control

This is a big one. While your St. Augustine is dormant and not competing, cool-season weeds are having the time of their lives. You’ll notice them more than ever because the brown lawn provides zero camouflage.

The best defense is a pre-emergent herbicide applied in early to mid-fall (September–October) before winter weeds germinate. If you missed that window, post-emergent spot treatments can help manage broadleaf weeds like chickweed and henbit during winter. Just avoid applying herbicides to stressed or dormant turf at extreme temperatures.

Foot Traffic

Minimize it. Dormant St. Augustine is more vulnerable to physical damage. Walking or driving on it can crush the stolons and compact the soil, making spring recovery harder. If you have fungal issues, foot traffic can also spread disease from one area of the lawn to another.

What to Do in South Florida (When It’s Not Dormancy)

If you’re south of I-4 and your St. Augustine looks rough in winter, the solution is usually nutritional — not just patience.

St. Augustine is a macronutrient-hungry grass. Those thick, fleshy stolons require consistent nitrogen and potassium to maintain themselves. When days get shorter and temperatures cool even slightly, the growth rate slows but the plant’s demands don’t disappear. If you’ve been running a light fertilization program, the lawn can spiral: it doesn’t have enough nutrients to maintain existing tissue or produce new growth to replace what’s dying back naturally.

If you’re still mowing every 10–14 days through December and January — meaning the grass is still actively growing — it needs to be fed. A balanced slow-release fertilizer or a potassium-forward product can make a dramatic difference. Iron applications can also help maintain color without pushing excessive growth.

Spring Green-Up: What to Expect

When soil temperatures climb back above 55–60°F, your dormant St. Augustine will begin to wake up. You’ll notice it first in the warmest microclimates — near sidewalks, driveways, south-facing walls, and sun-drenched areas.

Green-up isn’t instant. It’s a gradual process that can take several weeks. Resist the temptation to dump fertilizer on the lawn the moment you see the first green blade. Wait until the grass is consistently and actively growing before applying your first spring feeding. Pushing nitrogen too early can make the lawn vulnerable to late-season cold snaps and fungal diseases — particularly take-all root rot, which is notorious for attacking St. Augustine as it emerges from dormancy.

Once green-up is established and you’re mowing regularly, resume your normal fertilization schedule and watering routine.

The Bottom Line

Does St. Augustine grass go dormant in Florida? Absolutely — in the right conditions. If you’re in North Florida, it’s a near-certainty every winter. Central Florida is a coin flip depending on the year. And South Florida homeowners can usually skip the dormancy drama entirely, though winter stress is a real thing that deserves attention.

The most important takeaway: brown grass in winter is not an emergency. It’s biology doing exactly what it’s supposed to do. Your job is to understand what’s happening, provide the right care for the season, and let the grass do its thing.

If you’re unsure whether your lawn is dormant, dead, or dealing with something else entirely, a soil test can give you a clear picture of what’s going on below the surface. And if your lawn didn’t survive the winter, we can help you start fresh with professionally installed sod that’s matched to your specific region and growing conditions.

Need help getting your Florida lawn through winter — or recovering from one? Get a free quote from Floridist.