Mermentau, Louisiana, sits in USDA hardiness zone 9a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect artichoke, fig, california poppy, and cabbage to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Mermentau, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Mermentau lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Mermentau — soil, climate, flood, and parcel records. How we handle your address.
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Mermentau — the short answer
Mermentau, Louisiana: USDA zone 9a, about 311 days between hard freezes, across 1K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 30
- Acadia Parish normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 7
- Acadia Parish normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~311
- Acadia Parish normal — NOAA 1991–2020, nearest to this town
- Town area
- 1K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Acadia Parish’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Mermentau's average, not your lot's — a low corner or a tree line moves it. Against Mermentau's 311-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mermentau
Each reading below is measured for Mermentau itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMermentau runs about 311 days between hard freezes (read from Acadia Parish, the closest normal to Mermentau) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMermentau sits in USDA hardiness zone 9a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Mermentau is in
Mermentau sits in the Western Gulf Coastal Plain — EPA Level III, inside the wider Great Plains. That is read at Mermentau's own centroid rather than borrowed from Acadia Parish.
What Grows in Mermentau
Every plant below cleared Mermentau's own zone 9a and its 311-day season. Each card opens that plant's Louisiana profile. How we score.
Is it too late to plant in Mermentau?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Jan 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 7 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What's on the federal record near Mermentau
Closest first, within ~10 miles of Mermentau. Listing isn't leaking, and distance isn't exposure.
- DOLLAR GENERAL STORE 12783Brownfields · 1200 ft
- Ac-351Nitrate · 1400 ft
- Guidry's GroceryUnderground Storage Tanks · 1500 ft
- Keiths GulfUnderground Storage Tanks · 2100 ft
- LEEVAC SHIPYARDS JENNINGS, LLC.Brownfields · 0.8 mi
- PAI TRANSPORTATIONBrownfields · 0.9 mi
- ASCENSION PROCESSING COMPANY DBA GULF SOUTH PROCESSINGToxics Release Inventory · 1.0 mi
- GSX RECOVERY SYSTEMS INCToxics Release Inventory · 1.0 mi
- US LIQUIDS OF LA LP-MERMENTAUBrownfields · 1.0 mi
- BP BIOFUELS LA LLCBrownfields · 1.0 mi
- BP BIOFUELS LA LLCToxics Release Inventory · 1.0 mi
- MERMENTAU FACILITYBrownfields · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mermentau's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Mermentau.
Sources Checked
within ~10 miles of Mermentau
Severity Distribution
within ~10 miles of Mermentau
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mermentau, PFAS runs higher than the national average — 3 sites within ~10 miles of Mermentau. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Mermentau
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Mermentau average
Your land is one point inside Mermentau
Everything above resolves to Mermentau as a whole — one PHZM band, read across 1K acres, with hard-freeze dates borrowed from Acadia Parish’s record because no 30-year normal resolves at this town’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Mermentau Average
Mermentau Average
- ●USDA Zones 9a, averaged across Mermentau
- ●One soil character for all of Mermentau
- ●Frost dates read at Mermentau's scale: Jan 30 to Dec 7
YOUR Parcel
- ✓Your exact zone, not Mermentau's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mermentau
Pull a site-specific report for your exact address in Mermentau, Louisiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mermentau averages can't show:
We read public map data around Mermentau — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mermentau average
How we know this about Mermentau
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Acadia Parish’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Mermentau
When does frost risk typically end in Mermentau?
The last hard freeze (28°F) in Mermentau typically lands around Jan 30, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Feb 20.
When is the first frost in Mermentau?
The first hard freeze (28°F) in Mermentau typically arrives around Dec 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 23, so the watching starts about Nov 7 — about 311 days after the spring freeze cleared.
How long is the growing season in Mermentau?
Measured between 28°F hard freezes, Mermentau sees about 311 frost-free days — roughly Jan 30 through Dec 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 20 to Nov 23, about 276 days.
Is the soil safe to grow vegetables in Mermentau?
The federal record around Mermentau is a meaningful one — 327 documented sites, mostly Underground Storage Tanks entries (131), the nearest Brownfields record about 0.2 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Mermentau?
From about Nov 7 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Dec 7 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Dec 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Mermentau's scale — its 9a band and its 311-day season. Your yard writes its own version of Mermentau's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Mermentau’s own scale
5 of the readings below were taken at Mermentau's own scale — the 1,364 acres it covers and 327 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Mermentau's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 327 documented contamination sites on the federal record near Mermentau, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Mermentau's boundary and the 1,364 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~311-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mermentau's own centroid, the Western Gulf Coastal PlainUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Mermentau has no normal of its own, so its county's is the closest measured readfrom Acadia Parish
- Soil character — no town-scale survey exists, so Mermentau's 1,364 acres read through its county's SSURGO summaryfrom Acadia County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Acadia County
- The growing challenges every Louisiana grower plans around — written at state scale, so they stay on the state guidefrom Louisiana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Acadia County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mermentau's 1,364 acreswhy one lot differs from the next →
- Which side of Mermentau you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,364 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Mermentau-wide figureread your own land →
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