Duncan, South Carolina, sits in USDA hardiness zones 8a-9a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: peach, okra, muscadine grape, and palmetto. The site-level story — soil, sun, drainage — decides the rest.
Even in Duncan, 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 Duncan lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
8a-9a
Last Hard Freeze (28°F)
Jan 26
Town normal — light frosts run a few weeks later
First Frost (state avg.)
Oct 20 - Nov 20
Town Area
4K acres
Hardiness Zone Range
Growing Season (statewide frost window)
Zone maps are averages across Duncan. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Duncan
Plants matched to Duncan's USDA zones 8a-9a — each links to its full growing profile.
Growing Challenges in South Carolina
What an experienced grower plans around here — each one has a move.
Red Piedmont clay requires amendment for drainage
Compost opens red clay over time; a raised bed opens it today — both together is the Piedmont standard.
High heat and humidity promote diseases
Wide spacing, morning base-watering, and resistant varieties keep the humid summer honest — extension keeps the lists.
Hurricane risk along the coast
Coastal beds favor wind-tough perennials and well-staked young trees before the storm season.
For cultivar selection, pest pressure, and planting-time guidance specific to South Carolina, the Clemson Cooperative Extension is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
within ~10 miles of Duncan
Severity Distribution
within ~10 miles of Duncan
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Duncan, Toxic Release Inventory runs higher than the national average — 129 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Duncan
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Duncan Average
- ●USDA Zones 8a-9a
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Duncan
Pull a site-specific report for your exact address in Duncan, South Carolina — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Duncan, South Carolina
- USDA Hardiness Zones: 8a-9a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Jan 26 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Fall Frost (state avg.): Oct 20 - Nov 20 (NOAA 30-Year Climate Normals)
- Land Area: 4K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Duncan, South Carolina?
Duncan sits in USDA hardiness zones 8a-9a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Duncan?
The last hard freeze (28°F) in Duncan typically lands around Jan 26, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
What vegetables grow in Duncan?
Duncan's zones 8a-9a support a wide range — strong performers include Peach, Okra, Muscadine Grape, Palmetto, and Fig. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Duncan, really?
Officially, Duncan sits in USDA zones 8a-9a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Duncan?
The federal record around Duncan runs heavier than most — 1,036 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Duncan?
As the season closes around South Carolina's first fall frost near Oct 20 - Nov 20 (NOAA 30-year climate normals (1991–2020)), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.
Everything on this page is a Duncan average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
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