Jackson County, in Mississippi, sits in USDA hardiness zone 9a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit artichoke, fig, california poppy, and cabbage — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Jackson County lies within the Gulf Coast — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Jackson County holds more than one microclimate.
Soils and elevations shift across Jackson County, 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 Jackson County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Jackson County — the short answer
Jackson County, Mississippi: USDA zone 9a, about 298 days between hard freezes, across 463K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 11
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 6
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~298
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 463K 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 9a is Jackson County's average, not your lot's — a low corner or a tree line moves it. Against Jackson County's 298-day season, see what your own ground reads.
Heat and winter chill in Jackson County
Across a year, Jackson County accumulates about 6,434 growing degree days above 50°F, about 1,036 more than the middle Mississippi county — ahead of 80 of Mississippi’s 82 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 458 hours below 45°F, 734 fewer than the Mississippi middle of 1,192. 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 Jackson County
Across Jackson County, the ground is predominantly Ultisols, where Benndale, Vancleave, and Bayou are the most extensive named soil series. The soil is generally very poorly drained with a fine sandy loam surface. Topsoil pH runs about 5.0, very strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Ultisols
Drainage
Very poorly drained
Prime farmland
28%
Hydric soils
43%
Soil still varies lot by lot — soil types explained.
How the ground varies across Jackson County
The USDA soil survey maps 21% of Jackson County as very poorly drained — but another 69% drains differently: 19% well drained, 16% moderately well drained.
Benndale is the most extensive named soil at 9% of mapped acres, then Vancleave (6%) and Bayou (6%).
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 Jackson County
Each reading below is measured for Jackson County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Jackson County are very poorly drained, in hydrologic group C — 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 Jackson County runs about pH 5.0, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredJackson County runs about 298 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
MeasuredJackson County 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 Jackson County is in
Jackson County spans 2 EPA Level III ecoregions — Southern Coastal Plain (62%) and Southeastern Plains (38%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Jackson County
We scored all 1,086 plants against Jackson County's own USDA zone 9a and its own 298-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 Mississippi profile.
Is it too late to plant in Jackson County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
Documented around Jackson County
- monarch butterfly69 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Jackson County
USGS estimates 4,651 lb of Glyphosate on Jackson County farmland in 2019, its largest by weight, ahead of 2,4-d (1,972 lb) and Acetochlor (1,636 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 Jackson County — and how to grow with it.
We checked the federal record across Jackson County — 964 documented sites across 7 of the 9 source types we track.
The most significant on record: 8 Superfund sites. 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 Jackson 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 Jackson County
Closest first, across Jackson County. Listing isn't leaking, and distance isn't exposure.
- Singing River GroceryUnderground Storage Tanks · 0.5 mi
- 059O0008 JACKSONNitrate · 0.8 mi
- Martin Bluff Grocery (#240)Underground Storage Tanks · 0.8 mi
- Abandoned Circle KUnderground Storage Tanks · 0.9 mi
- PETERS AUTOBrownfields · 1.0 mi
- 059K0037 JACKSONNitrate · 1.8 mi
- 059K0151 JACKSONNitrate · 2.7 mi
- Gautier Regional Pump StationUnderground Storage Tanks · 2.7 mi
- Fayard'sUnderground Storage Tanks · 2.7 mi
- 059K0036 JACKSONNitrate · 2.8 mi
- Fast Mart #29Underground Storage Tanks · 2.8 mi
- Gautier Reg Wastewater Treatment PlantUnderground Storage Tanks · 2.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Jackson County'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 Jackson County.
Sources Checked
across Jackson County
Severity Distribution
across Jackson County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jackson County, two things run higher than the national average across Jackson County — Nitrate (364 sites) and PFAS (9 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Jackson County
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 Jackson County average
Your land is one point inside Jackson County
Everything above resolves to Jackson County as a whole — one PHZM band and one county frost record, read across 463K 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 Jackson County Average
Jackson County Average
- ●USDA Zones 9a, averaged across Jackson County
- ●One soil character for all of Jackson County
- ●Frost dates read at Jackson County's scale: Feb 11 to Dec 6
YOUR Parcel
- ✓Your exact zone, not Jackson County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Jackson County
Pull a site-specific report for your exact address in Jackson County, Mississippi — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jackson County averages can't show:
We read public map data around Jackson County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jackson County average
How we know this about Jackson County
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 Jackson County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Jackson County
When does frost risk typically end in Jackson County?
The last hard freeze (28°F) in Jackson County typically lands around Feb 11, 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 Mar 4.
How long is the growing season in Jackson County?
Measured between 28°F hard freezes, Jackson County sees about 298 frost-free days — roughly Feb 11 through Dec 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 4 to Nov 22, about 263 days.
Is the soil safe to grow vegetables in Jackson County?
The federal record around Jackson County is a meaningful one — 964 documented sites, mostly Nitrate entries (364), the nearest Underground Storage Tanks record about 0.5 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 Jackson County's scale — its 9a band and its 298-day season. Your yard writes its own version of Jackson County'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 Mississippi's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Jackson County’s own scale
9 of the readings below were taken at Jackson County's own scale — its own ~298-day span between 28°F freezes, the 3 most extensive soil series mapped here and 964 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Jackson County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Jackson County's own 28°F hard-freeze dates and its ~298-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Jackson CountyUSDA NRCS SSURGO
- 964 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.5 miles outFederal environmental registers
- Jackson County's boundary and the 462,608 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~298-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Jackson County spans, Southern Coastal Plain the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Jackson County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Jackson County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Mississippi grower plans around — written at state scale, so they stay on the state guidefrom Mississippi
What this page can’t tell you
- How the season shifts across Jackson County — the ~298 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 Jackson County's 462,608 acreswhy one lot differs from the next →
- Which of those 964 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 Jackson Countyread your own land →