Jefferson, Louisiana, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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.
Even in Jefferson, 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 Jefferson 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 Jefferson — soil, climate, flood, and parcel records. How we handle your address.
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Jefferson — the short answer
Jefferson, Louisiana: USDA zone 9b, about 336 days between hard freezes, across 2K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 18
- Jefferson Parish normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 20
- Jefferson Parish normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~336
- Jefferson Parish normal — NOAA 1991–2020, nearest to this town
- Town area
- 2K 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 Jefferson Parish’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Jefferson's average, not your lot's — a low corner or a tree line moves it. Against Jefferson's 336-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Jefferson
Each reading below is measured for Jefferson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsJefferson runs about 336 days between hard freezes (read from Jefferson Parish, the closest normal to Jefferson) — 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
MeasuredJefferson 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 Jefferson is in
Jefferson sits in the Mississippi Alluvial Plain — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Jefferson's own centroid rather than borrowed from Jefferson Parish.
What Grows in Jefferson
Every plant below cleared Jefferson's own zone 9b and its 336-day season. Each card opens that plant's Louisiana profile. How we score.
Is it too late to plant in Jefferson?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 20 — 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 Jefferson
Closest first, within ~10 miles of Jefferson. Listing isn't leaking, and distance isn't exposure.
- DAN TRAN 1 HR MARTBrownfields · 650 ft
- Ochsner Clinic Foundation - Former Jefferson Plaza Dry CleanersUnderground Storage Tanks · 950 ft
- FOXS FOREIGN CAR RPRBrownfields · 950 ft
- ABF Freight Systems IncUnderground Storage Tanks · 1000 ft
- TIRES INCBrownfields · 1000 ft
- INTERCOASTAL MARINE RPRS INCBrownfields · 1100 ft
- OCHSNER SELECT REHAB (OSR)Brownfields · 1100 ft
- RaceTrac #2493Underground Storage Tanks · 1200 ft
- Labarre Office BuildingUnderground Storage Tanks · 1200 ft
- EXXON CO USA 52473Brownfields · 1200 ft
- VALVOLINE INSTANT OIL CHANGE II0003Brownfields · 1300 ft
- United Parcel Service Inc (UPS)Underground Storage Tanks · 1300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Jefferson'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 Jefferson.
Sources Checked
within ~10 miles of Jefferson
Severity Distribution
within ~10 miles of Jefferson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jefferson, Brownfields runs higher than the national average — 3,262 sites within ~10 miles of Jefferson. That's not a problem with your land — it's information about it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Jefferson
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 Jefferson average
Your land is one point inside Jefferson
Everything above resolves to Jefferson as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Jefferson 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 Jefferson Average
Jefferson Average
- ●USDA Zones 9b, averaged across Jefferson
- ●One soil character for all of Jefferson
- ●Frost dates read at Jefferson's scale: Jan 18 to Dec 20
YOUR Parcel
- ✓Your exact zone, not Jefferson's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Jefferson
Pull a site-specific report for your exact address in Jefferson, Louisiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jefferson averages can't show:
We read public map data around Jefferson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jefferson average
How we know this about Jefferson
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 Jefferson 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 Jefferson
When does frost risk typically end in Jefferson?
The last hard freeze (28°F) in Jefferson 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.
When is the first frost in Jefferson?
The first hard freeze (28°F) in Jefferson typically arrives around Dec 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 6, so the watching starts about Nov 20 — about 336 days after the spring freeze cleared.
How long is the growing season in Jefferson?
Measured between 28°F hard freezes, Jefferson sees about 336 frost-free days — roughly Jan 18 through Dec 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 8 to Dec 6, about 301 days.
Is the soil safe to grow vegetables in Jefferson?
The federal record around Jefferson is a meaningful one — 5,362 documented sites, mostly Brownfields entries (3,262), the nearest Brownfields record about 0.1 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 Jefferson?
From about Nov 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Jefferson's scale — its 9b band and its 336-day season. Your yard writes its own version of Jefferson'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 Jefferson’s own scale
5 of the readings below were taken at Jefferson's own scale — the 1,732 acres it covers and 5,362 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Jefferson's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 5,362 documented contamination sites on the federal record near Jefferson, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Jefferson's boundary and the 1,732 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~336-day seasonGrowable Ground crop-matching engine
- The ecoregion at Jefferson's own centroid, the Mississippi Alluvial PlainUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Jefferson has no normal of its own, so its county's is the closest measured readfrom Jefferson Parish
- Soil character — no town-scale survey exists, so Jefferson's 1,732 acres read through its county's SSURGO summaryfrom Jefferson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jefferson 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 Jefferson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Jefferson's 1,732 acreswhy one lot differs from the next →
- Which side of Jefferson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,732 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Jefferson-wide figureread your own land →