Swain County, in North Carolina, sits in USDA hardiness zone 6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cabbage, blackberry, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Swain County lies within the Blue Ridge and Appalachia — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Swain County holds more than one microclimate.
Soils and elevations shift across Swain 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 Swain County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Swain County — the short answer
Swain County, North Carolina: USDA zone 6b, about 178 days between hard freezes, across 338K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~178
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 338K 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 6b is Swain County's average, not your lot's — a low corner or a tree line moves it. Against Swain County's 178-day season, see what your own ground reads.
Heat in Swain County
Across a year, Swain County accumulates about 1,742 growing degree days above 50°F, about 2,648 fewer than the middle North Carolina county — no other North Carolina county banks fewer. 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.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Swain County
Across Swain County, the ground is predominantly Inceptisols, where Soco, Stecoah, and Junaluska are the most extensive named soil series. The soil is generally well drained with a channery loam surface. Topsoil pH runs about 4.5–4.8, very strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Inceptisols
Drainage
Well drained
Prime farmland
0%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Swain County
The USDA soil survey maps 91% of Swain County as well drained — but another 7% drains differently: 4% somewhat excessively drained, 2% excessively drained.
Soco is the most extensive named soil at 19% of mapped acres, then Stecoah (12%) and Junaluska (11%).
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 Swain County
Each reading below is measured for Swain 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 Swain County are well drained, in hydrologic group B — 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 Swain County runs about pH 4.5–4.8, 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
MeasuredSwain County runs about 178 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSwain County sits in USDA hardiness zone 6b.
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 Swain County is in
Swain County sits in the Blue Ridge — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Swain County
We scored all 1,086 plants against Swain County's own USDA zone 6b and its own 178-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 North Carolina profile.
Is it too late to plant in Swain 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 Mar 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Swain County
Survey cells within 31 miles of Swain County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 38 miles off. What to watch for.
- Japanese beetle3 documented records
- monarch butterfly12 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Swain County
USGS estimates 355 lb of Metolachlor & Metolachlor-s on Swain County farmland in 2019, its largest by weight, ahead of Metolachlor-s (321 lb) and 2,4-d (317 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 Swain County — and how to grow with it.
We checked the federal record across Swain County — 128 documented sites across 6 of the 9 source types we track.
The most significant on record: 3 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Swain 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 Swain County
Closest first, across Swain County. Listing isn't leaking, and distance isn't exposure.
- CHEROKEE WATER SYSTEMPFAS · 5.0 mi
- Silers Bald ProspectsMining · 5.6 mi
- Silers Bald ProspectMining · 5.7 mi
- SW-048 NR CHEROKEE, NC QUARTZITENitrate · 7.1 mi
- HYATT CREEK EXXONUnderground Storage Tanks · 8.3 mi
- KAYCHA LABS NC, LLCBrownfields · 8.5 mi
- Branton Feldspar MineMining · 8.6 mi
- PHIL-CO HDW BLDG SUP INC.Underground Storage Tanks · 8.8 mi
- CARL ELLERUnderground Storage Tanks · 8.8 mi
- TRIBAL GARAGEUnderground Storage Tanks · 8.9 mi
- COOPERS CREEK GENERAL STOREUnderground Storage Tanks · 8.9 mi
- MONTIETH LUMBER CO.Underground Storage Tanks · 9.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Swain 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 Swain County.
Total Sites
128
across Swain County
Risk Level
Elevated
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
across Swain County
Severity Distribution
across Swain County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Swain County, two things run higher than the national average across Swain County — Mining (19 sites) and Underground Storage Tanks (93 sites). That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Swain 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 Swain County average
Your land is one point inside Swain County
Everything above resolves to Swain County as a whole — one PHZM band and one county frost record, read across 338K 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 Swain County Average
Swain County Average
- ●USDA Zones 6b, averaged across Swain County
- ●One soil character for all of Swain County
- ●Frost dates read at Swain County's scale: Apr 27 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Swain County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Swain County
Pull a site-specific report for your exact address in Swain County, North Carolina — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Swain County averages can't show:
We read public map data around Swain County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Swain County average
How we know this about Swain 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 Swain County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Swain County
When does frost risk typically end in Swain County?
The last hard freeze (28°F) in Swain County typically lands around Apr 27, 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 May 18.
How long is the growing season in Swain County?
Measured between 28°F hard freezes, Swain County sees about 178 frost-free days — roughly Apr 27 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Oct 8, about 143 days.
Is the soil safe to grow vegetables in Swain County?
The federal record around Swain County is a meaningful one — 128 documented sites, mostly Underground Storage Tanks entries (93), the nearest PFAS record about 5.0 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 Swain County's scale — its 6b band and its 178-day season. Your yard writes its own version of Swain 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 North Carolina's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Swain County’s own scale
9 of the readings below were taken at Swain County's own scale — its own ~178-day span between 28°F freezes, the 3 most extensive soil series mapped here and 128 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Swain County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Swain County's own 28°F hard-freeze dates and its ~178-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Swain CountyUSDA NRCS SSURGO
- 128 documented contamination sites inside the county boundary, distance-sorted from its center — the closest PFAS record about 5.0 miles outFederal environmental registers
- Swain County's boundary and the 337,743 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~178-day seasonGrowable Ground crop-matching engine
- Swain County sitting wholly inside the Blue RidgeUS EPA Level III Ecoregions
- Open occurrence records documented in Swain County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Swain County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every North Carolina grower plans around — written at state scale, so they stay on the state guidefrom North Carolina
What this page can’t tell you
- How the season shifts across Swain County — the ~178 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 Swain County's 337,743 acreswhy one lot differs from the next →
- Which of those 128 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 Swain Countyread your own land →