St. Charles Parish, in Louisiana, sits in USDA hardiness zone 9b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include okra, meyer lemon, california poppy, and artichoke — though what thrives on any one site still turns on its specific soil, sun, and drainage.
St. Charles Parish lies within Greater New Orleans and the Mississippi Delta — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
St. Charles Parish holds more than one microclimate.
Soils and elevations shift across St. Charles Parish, so your frost dates and drainage aren't the county average. 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 St. Charles Parish — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
St. Charles Parish — the short answer
St. Charles Parish, Louisiana: USDA zone 9b, about 337 days between hard freezes, across 178K acres.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 18
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~337
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 178K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 9b is St. Charles Parish's average, not your lot's — a low corner or a tree line moves it. Against St. Charles Parish's 337-day season, see what your own ground reads.
Heat and winter chill in St. Charles Parish
Across a year, St. Charles Parish accumulates about 7,217 growing degree days above 50°F, about 921 more than the middle Louisiana county — ahead of 60 of Louisiana’s 64 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Winter banks about 96 hours below 45°F, 516 fewer than the Louisiana middle of 612. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in St. Charles County
Across St. Charles County, the ground is predominantly Histosols, where Kenner, Barbary, and Cancienne are the most extensive named soil series. The soil is generally very poorly drained with a clay surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Histosols
Drainage
Very poorly drained
Prime farmland
15%
Hydric soils
83%
Soil still varies lot by lot — soil types explained.
How the ground varies across St. Charles Parish
The USDA soil survey maps 41% of St. Charles Parish as very poorly drained — but another 23% drains differently: 12% somewhat poorly drained, 11% poorly drained.
Kenner is the most extensive named soil at 33% of mapped acres, then Barbary (17%) and Cancienne (17%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in St. Charles Parish
Each reading below is measured for St. Charles Parish itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across St. Charles Parish are very poorly drained, in hydrologic group D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across St. Charles Parish runs about pH 6.2–6.7, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredSt. Charles Parish runs about 337 days between hard freezes — 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
MeasuredSt. Charles Parish sits in USDA hardiness zone 9b.
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 St. Charles Parish is in
St. Charles Parish sits in the Mississippi Alluvial Plain — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in St. Charles Parish
We scored all 1,086 plants against St. Charles Parish's own USDA zone 9b and its own 337-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Louisiana profile.
Is it too late to plant in St. Charles Parish?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 21 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around St. Charles Parish
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in St. Charles Parish
USGS estimates 9,542 lb of Glyphosate on St. Charles Parish farmland in 2019, its largest by weight, ahead of 2,4-d (2,174 lb) and Triclopyr (269 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across St. Charles County — and how to grow with it.
We checked the federal record across St. Charles County — 490 documented sites across 6 of the 9 source types we track.
The most significant on record: 4 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across St. Charles County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near St. Charles Parish
Closest first, across St. Charles County. Listing isn't leaking, and distance isn't exposure.
- BellSouth Telecommunications - Linglabu - J2535Underground Storage Tanks · 1100 ft
- Entergy Louisiana IncUnderground Storage Tanks · 2300 ft
- Mimosa ServicesUnderground Storage Tanks · 2300 ft
- CHUCK GAINESBrownfields · 2300 ft
- Mimosa Veterinary HospitalUnderground Storage Tanks · 0.5 mi
- Ray's Auto RepairUnderground Storage Tanks · 0.6 mi
- ST CHARLES PARISH COUNCILBrownfields · 0.6 mi
- Ecol #9099Underground Storage Tanks · 0.6 mi
- DOLLAR GENERAL #14815Brownfields · 0.6 mi
- PRIVATE VEHICLE WRECK CLEANUPBrownfields · 0.6 mi
- TODAYS CAR CARE INCBrownfields · 0.7 mi
- Petes Gator Stop #9Underground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Charles Parish'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 St. Charles Parish.
Total Sites
490
across St. Charles County
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
across St. Charles County
Severity Distribution
across St. Charles County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Charles Parish, Toxics Release Inventory runs higher than the national average — 41 sites across St. Charles County. That's not a problem with your land — it's information about it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in St. Charles Parish
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 St. Charles Parish average
Your land is one point inside St. Charles Parish
Everything above resolves to St. Charles Parish as a whole — one PHZM band and one county frost record, read across 178K acres. 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 county 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 county average.
Your Lot vs the St. Charles Parish Average
St. Charles Parish Average
- ●USDA Zones 9b, averaged across St. Charles Parish
- ●One soil character for all of St. Charles Parish
- ●Frost dates read at St. Charles Parish's scale: Jan 18 to Dec 21
YOUR Parcel
- ✓Your exact zone, not St. Charles Parish's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in St. Charles Parish
Pull a site-specific report for your exact address in St. Charles Parish, Louisiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Charles Parish averages can't show:
We read public map data around St. Charles Parish — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Charles Parish average
How we know this about St. Charles Parish
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where St. Charles Parish carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about St. Charles Parish
When does frost risk typically end in St. Charles Parish?
The last hard freeze (28°F) in St. Charles Parish typically lands around Jan 18, 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 8.
How long is the growing season in St. Charles Parish?
Measured between 28°F hard freezes, St. Charles Parish sees about 337 frost-free days — roughly Jan 18 through Dec 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 8 to Dec 7, about 302 days.
Is the soil safe to grow vegetables in St. Charles Parish?
The federal record around St. Charles Parish is a meaningful one — 490 documented sites, mostly Brownfields entries (231), the nearest Underground Storage Tanks 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.
Everything above is measured at St. Charles Parish's scale — its 9b band and its 337-day season. Your yard writes its own version of St. Charles Parish's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Louisiana's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at St. Charles Parish’s own scale
9 of the readings below were taken at St. Charles Parish's own scale — its own ~337-day span between 28°F freezes, the 3 most extensive soil series mapped here and 490 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- St. Charles Parish's own USDA hardiness band, zones 9bUSDA PHZM 2023
- St. Charles Parish's own 28°F hard-freeze dates and its ~337-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in St. Charles ParishUSDA NRCS SSURGO
- 490 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.2 miles outFederal environmental registers
- St. Charles Parish's boundary and the 177,755 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~337-day seasonGrowable Ground crop-matching engine
- St. Charles Parish sitting wholly inside the Mississippi Alluvial PlainUS EPA Level III Ecoregions
- Open occurrence records documented in St. Charles Parish for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto St. Charles Parish farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Louisiana grower plans around — written at state scale, so they stay on the state guidefrom Louisiana
What this page can’t tell you
- How the season shifts across St. Charles Parish — the ~337 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among St. Charles Parish's 177,755 acreswhy one lot differs from the next →
- Which of those 490 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over St. Charles Parishread your own land →