Port Gibson, Mississippi, sits in USDA hardiness zone 8b — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, fig, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Port Gibson, 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 Port Gibson 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 Port Gibson — soil, climate, flood, and parcel records. How we handle your address.
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Port Gibson — the short answer
Port Gibson, Mississippi: USDA zone 8b, about 278 days between hard freezes, across 1K acres of city.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 20
- Claiborne County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 25
- Claiborne County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~278
- Claiborne County normal — NOAA 1991–2020, nearest to this town
- City 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 Claiborne County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Port Gibson's average, not your lot's — a low corner or a tree line moves it. Against Port Gibson's 278-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Port Gibson
Each reading below is measured for Port Gibson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsPort Gibson runs about 278 days between hard freezes (read from Claiborne County, the closest normal to Port Gibson) — 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
MeasuredPort Gibson sits in USDA hardiness zone 8b.
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 Port Gibson is in
Port Gibson sits in the Mississippi Valley Loess Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Port Gibson's own centroid rather than borrowed from Claiborne County.
What Grows in Port Gibson
Every plant below cleared Port Gibson's own zone 8b and its 278-day season. Each card opens that plant's Mississippi profile. How we score.
Is it too late to plant in Port Gibson?
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 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 25 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near Port Gibson
Closest first, within ~10 miles of Port Gibson. Listing isn't leaking, and distance isn't exposure.
- 021L0003 CLAIBORNENitrate · 750 ft
- Cleveland Service Station Exxon #5Underground Storage Tanks · 1100 ft
- Horace LightfootUnderground Storage Tanks · 1600 ft
- Hill City OilUnderground Storage Tanks · 2200 ft
- US POST OFFICE AND FEDERAL BUILDINGBrownfields · 2200 ft
- Port Gibson City BarnUnderground Storage Tanks · 2200 ft
- Port Gibson Service StationUnderground Storage Tanks · 2300 ft
- Beesley Oil CompanyUnderground Storage Tanks · 2300 ft
- Sheriff's DepartmentUnderground Storage Tanks · 2500 ft
- AMERICAN PAPER TUBE COMPANYToxics Release Inventory · 0.5 mi
- A & W GroceryUnderground Storage Tanks · 0.5 mi
- Bruce Hardwood FlooringUnderground Storage Tanks · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Port Gibson'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 Port Gibson.
Total Sites
60
within ~10 miles of Port Gibson
Risk Level
Moderate
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Port Gibson
Severity Distribution
within ~10 miles of Port Gibson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Port Gibson, two things run higher than the national average within ~10 miles of Port Gibson — Toxics Release Inventory (5 sites) and Underground Storage Tanks (42 sites). 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.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Port Gibson
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 Port Gibson average
Your land is one point inside Port Gibson
Everything above resolves to Port Gibson as a whole — one PHZM band, read across 1K acres, with hard-freeze dates borrowed from Claiborne County’s record because no 30-year normal resolves at this city’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 city 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 Port Gibson Average
Port Gibson Average
- ●USDA Zones 8b, averaged across Port Gibson
- ●One soil character for all of Port Gibson
- ●Frost dates read at Port Gibson's scale: Feb 20 to Nov 25
YOUR Parcel
- ✓Your exact zone, not Port Gibson's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Port Gibson
Pull a site-specific report for your exact address in Port Gibson, Mississippi — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Port Gibson averages can't show:
We read public map data around Port Gibson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Port Gibson average
How we know this about Port Gibson
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Claiborne County’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 city grain anywhere on this page — there is no city-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 Port Gibson
When does frost risk typically end in Port Gibson?
The last hard freeze (28°F) in Port Gibson typically lands around Feb 20, 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 13.
When is the first frost in Port Gibson?
The first hard freeze (28°F) in Port Gibson typically arrives around Nov 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 11, so the watching starts about Oct 26 — about 278 days after the spring freeze cleared.
How long is the growing season in Port Gibson?
Measured between 28°F hard freezes, Port Gibson sees about 278 frost-free days — roughly Feb 20 through Nov 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 13 to Nov 11, about 243 days.
Is the soil safe to grow vegetables in Port Gibson?
The federal record around Port Gibson shows 60 documented sites, mostly Underground Storage Tanks entries (42), the nearest Nitrate record about 0.1 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Port Gibson?
From about Oct 26 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 Nov 25 (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 Nov 25. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Port Gibson's scale — its 8b band and its 278-day season. Your yard writes its own version of Port Gibson'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 Port Gibson’s own scale
5 of the readings below were taken at Port Gibson's own scale — the 1,123 acres it covers and 60 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Port Gibson's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 60 documented contamination sites on the federal record near Port Gibson, the closest Nitrate record about 0.1 miles out from the town centreFederal environmental registers
- Port Gibson's boundary and the 1,123 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~278-day seasonGrowable Ground crop-matching engine
- The ecoregion at Port Gibson's own centroid, the Mississippi Valley Loess PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Port Gibson has no normal of its own, so its county's is the closest measured readfrom Claiborne County
- Soil character — no town-scale survey exists, so Port Gibson's 1,123 acres read through its county's SSURGO summaryfrom Claiborne County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Claiborne County
- The growing challenges every Mississippi grower plans around — written at state scale, so they stay on the state guidefrom Mississippi
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Claiborne County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Port Gibson's 1,123 acreswhy one lot differs from the next →
- Which side of Port Gibson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,123 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Port Gibson-wide figureread your own land →