Barnwell County, in South Carolina, sits in USDA hardiness zone 8b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, fig, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Barnwell County holds more than one microclimate.
Soils and elevations shift across Barnwell 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 Barnwell County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Barnwell County — the short answer
Barnwell County, South Carolina: USDA zone 8b, about 275 days between hard freezes, across 351K acres.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 26
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 28
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~275
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 351K 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 8b is Barnwell County's average, not your lot's — a low corner or a tree line moves it. Against Barnwell County's 275-day season, see what your own ground reads.
Heat and winter chill in Barnwell County
Across a year, Barnwell County accumulates about 5,486 growing degree days above 50°F, about 338 more than the middle South Carolina county — ahead of 34 of South Carolina’s 46 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 1,128 hours below 45°F, 234 fewer than the South Carolina middle of 1,362. 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 Barnwell County
Across Barnwell County, the ground is predominantly Ultisols, where Wagram, Blanton, and Barnwell are the most extensive named soil series. The soil is generally well drained with a sand surface. Topsoil pH runs about 5.3, strongly acidic. Rainfall drains through hydrologic group A soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
8%
Hydric soils
20%
Soil still varies lot by lot — soil types explained.
How the ground varies across Barnwell County
The USDA soil survey maps 54% of Barnwell County as well drained — but another 44% drains differently: 21% moderately well drained, 11% poorly drained.
Wagram is the most extensive named soil at 24% of mapped acres, then Blanton (22%) and Barnwell (16%).
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 Barnwell County
Each reading below is measured for Barnwell 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 Barnwell County are well drained, in hydrologic group A — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Barnwell County runs about pH 5.3, 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
Wet ground
MeasuredAbout 20% of Barnwell County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredBarnwell County runs about 275 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
The kind of country Barnwell County is in
Barnwell County sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Barnwell County
We scored all 1,086 plants against Barnwell County's own USDA zone 8b and its own 275-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 South Carolina profile.
Is it too late to plant in Barnwell County?
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 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 28 — 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.
Documented around Barnwell County
Survey cells within 31 miles of Barnwell County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 158 miles off. What to watch for.
- monarch butterfly17 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Barnwell County
USGS estimates 25,629 lb of Acetochlor on Barnwell County farmland in 2019, its largest by weight, ahead of Glyphosate (24,772 lb) and Dicamba (8,690 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 Barnwell County — and how to grow with it.
We checked the federal record across Barnwell County — 209 documented sites across 6 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 Barnwell 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 Barnwell County
Closest first, across Barnwell County. Listing isn't leaking, and distance isn't exposure.
- ENERGYSOLUTIONS BARNWELL RCRA PROCESSING FACILITYBrownfields · 1.9 mi
- BARNWELL PROCESSING FACILITYBrownfields · 1.9 mi
- CHEM NUCLEAR SYSTEMS LLCBrownfields · 2.3 mi
- CHEM NUCLEAR SYSTEMS LLCUnderground Storage Tanks · 2.3 mi
- ALLIED GENERAL NUCLEAR SERVICESUnderground Storage Tanks · 2.3 mi
- TRI STATE MOTOR TRANSITBrownfields · 2.4 mi
- PATTERSON MILL GROCERYUnderground Storage Tanks · 2.4 mi
- BW- 65Nitrate · 2.5 mi
- EFCO CORPToxics Release Inventory · 2.6 mi
- WALMART SUPERCENTER #795Brownfields · 2.8 mi
- RAINBOW GAS GARDEN 11Underground Storage Tanks · 2.9 mi
- KOCH & CO., INC - BARNWELL PLANTBrownfields · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Barnwell 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 Barnwell County.
Sources Checked
across Barnwell County
Severity Distribution
across Barnwell County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Barnwell County, two things run higher than the national average across Barnwell County — Superfund (8 sites) and Nitrate (62 sites). That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Barnwell 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 Barnwell County average
Your land is one point inside Barnwell County
Everything above resolves to Barnwell County as a whole — one PHZM band and one county frost record, read across 351K 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 Barnwell County Average
Barnwell County Average
- ●USDA Zones 8b, averaged across Barnwell County
- ●One soil character for all of Barnwell County
- ●Frost dates read at Barnwell County's scale: Feb 26 to Nov 28
YOUR Parcel
- ✓Your exact zone, not Barnwell County's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Barnwell County
Pull a site-specific report for your exact address in Barnwell County, South Carolina — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Barnwell County averages can't show:
We read public map data around Barnwell County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Barnwell County average
How we know this about Barnwell 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 Barnwell County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Barnwell County
When does frost risk typically end in Barnwell County?
The last hard freeze (28°F) in Barnwell County typically lands around Feb 26, 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 19.
How long is the growing season in Barnwell County?
Measured between 28°F hard freezes, Barnwell County sees about 275 frost-free days — roughly Feb 26 through Nov 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 19 to Nov 14, about 240 days.
Is the soil safe to grow vegetables in Barnwell County?
The federal record around Barnwell County is a meaningful one — 209 documented sites, mostly Underground Storage Tanks entries (95), the nearest Brownfields record about 1.9 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 Barnwell County's scale — its 8b band and its 275-day season. Your yard writes its own version of Barnwell 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 South Carolina's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Barnwell County’s own scale
9 of the readings below were taken at Barnwell County's own scale — its own ~275-day span between 28°F freezes, the 3 most extensive soil series mapped here and 209 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Barnwell County's own USDA hardiness band, zones 8bUSDA PHZM 2023
- Barnwell County's own 28°F hard-freeze dates and its ~275-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Barnwell CountyUSDA NRCS SSURGO
- 209 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 1.9 miles outFederal environmental registers
- Barnwell County's boundary and the 350,965 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~275-day seasonGrowable Ground crop-matching engine
- Barnwell County sitting wholly inside the Southeastern PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Barnwell County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Barnwell County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every South Carolina grower plans around — written at state scale, so they stay on the state guidefrom South Carolina
What this page can’t tell you
- How the season shifts across Barnwell County — the ~275 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 Barnwell County's 350,965 acreswhy one lot differs from the next →
- Which of those 209 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 Barnwell Countyread your own land →