Marlboro County, in South Carolina, sits in USDA hardiness zone 8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, fig, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Marlboro County lies within the Pee Dee — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Marlboro County holds more than one microclimate.
Soils and elevations shift across Marlboro 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 Marlboro County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Marlboro County — the short answer
Marlboro County, South Carolina: USDA zone 8a, about 261 days between hard freezes, across 307K acres.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 9
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~261
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 307K 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 8a is Marlboro County's average, not your lot's — a low corner or a tree line moves it. Against Marlboro County's 261-day season, see what your own ground reads.
Heat and winter chill in Marlboro County
Across a year, Marlboro County accumulates about 5,013 growing degree days above 50°F, about 135 fewer than the middle South Carolina county — ahead of 16 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 1,448 hours below 45°F, 86 more 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 Marlboro County
Across Marlboro County, the ground is predominantly Ultisols, where Coxville, Noboco, and Norfolk are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 4.8–5.3, very strongly acidic. Rainfall drains through hydrologic group C/D soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
31%
Hydric soils
33%
Soil still varies lot by lot — soil types explained.
How the ground varies across Marlboro County
The USDA soil survey maps 37% of Marlboro County as well drained — but another 61% drains differently: 25% poorly drained, 14% moderately well drained.
Coxville is the most extensive named soil at 10% of mapped acres, then Noboco (8%) and Norfolk (7%).
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 Marlboro County
Each reading below is measured for Marlboro 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 Marlboro County are well drained, in hydrologic group C/D — 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 Marlboro County runs about pH 4.8–5.3, 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 33% of Marlboro 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
MeasuredMarlboro County runs about 261 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 Marlboro County is in
Marlboro 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 Marlboro County
We scored all 1,086 plants against Marlboro County's own USDA zone 8a and its own 261-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 Marlboro County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 9 (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. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around Marlboro County
Survey cells within 31 miles of Marlboro County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 89 miles off. What to watch for.
What gets applied to farmland in Marlboro County
USGS estimates 71,539 lb of Glyphosate on Marlboro County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (23,345 lb) and Metolachlor-s (17,713 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 Marlboro County — and how to grow with it.
We checked the federal record across Marlboro County — 232 documented sites across 6 of the 9 source types we track.
The most significant on record: 6 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 Marlboro 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 Marlboro County
Closest first, across Marlboro County. Listing isn't leaking, and distance isn't exposure.
- BENNETTSVILLE MAINTENANCE FACUnderground Storage Tanks · 800 ft
- MARLBORO SCHOOL BUS SHOPUnderground Storage Tanks · 1600 ft
- SCARNG BENNETTSVILLEBrownfields · 2100 ft
- SAV WAY 16Underground Storage Tanks · 2100 ft
- OM & MILI INCUnderground Storage Tanks · 2200 ft
- GRIFFIN FLYTHE CHEVROLET HONDABrownfields · 2200 ft
- BREAKERS 121Underground Storage Tanks · 2400 ft
- BREAKERS 102Underground Storage Tanks · 2400 ft
- POLSTONS 66Underground Storage Tanks · 2400 ft
- FAMILY DOLLAR 65Brownfields · 2600 ft
- AUTO FOUNTAIN BYPASSUnderground Storage Tanks · 2600 ft
- ADVANCE CUP CORPUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Marlboro 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 Marlboro County.
Total Sites
232
across Marlboro County
Risk Level
Elevated
Highest-severity
6 Superfund sites (none NPL-listed)
Sources Checked
across Marlboro County
Severity Distribution
across Marlboro County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Marlboro County, two things run higher than the national average across Marlboro County — Superfund (6 sites) and Toxics Release Inventory (17 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.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Marlboro 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 Marlboro County average
Your land is one point inside Marlboro County
Everything above resolves to Marlboro County as a whole — one PHZM band and one county frost record, read across 307K 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 Marlboro County Average
Marlboro County Average
- ●USDA Zones 8a, averaged across Marlboro County
- ●One soil character for all of Marlboro County
- ●Frost dates read at Marlboro County's scale: Mar 9 to Nov 25
YOUR Parcel
- ✓Your exact zone, not Marlboro County's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Marlboro County
Pull a site-specific report for your exact address in Marlboro County, South Carolina — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Marlboro County averages can't show:
We read public map data around Marlboro County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Marlboro County average
How we know this about Marlboro 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 Marlboro County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Marlboro County
When does frost risk typically end in Marlboro County?
The last hard freeze (28°F) in Marlboro County typically lands around Mar 9, 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 30.
How long is the growing season in Marlboro County?
Measured between 28°F hard freezes, Marlboro County sees about 261 frost-free days — roughly Mar 9 through Nov 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 30 to Nov 11, about 226 days.
Is the soil safe to grow vegetables in Marlboro County?
The federal record around Marlboro County is a meaningful one — 232 documented sites, mostly Underground Storage Tanks entries (163), the nearest Underground Storage Tanks 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.
Everything above is measured at Marlboro County's scale — its 8a band and its 261-day season. Your yard writes its own version of Marlboro 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 Marlboro County’s own scale
8 of the readings below were taken at Marlboro County's own scale — its own ~261-day span between 28°F freezes, the 3 most extensive soil series mapped here and 232 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Marlboro County's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Marlboro County's own 28°F hard-freeze dates and its ~261-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Marlboro CountyUSDA NRCS SSURGO
- 232 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.1 miles outFederal environmental registers
- Marlboro County's boundary and the 307,119 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~261-day seasonGrowable Ground crop-matching engine
- Marlboro County sitting wholly inside the Southeastern PlainsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Marlboro 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 Marlboro County — the ~261 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 Marlboro County's 307,119 acreswhy one lot differs from the next →
- Which of those 232 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 Marlboro Countyread your own land →