Johnston, South Carolina, sits in USDA hardiness zone 8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
These conditions suit cabbage, fig, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Johnston, 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 Johnston 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 Johnston — soil, climate, flood, and parcel records. How we handle your address.
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Johnston — the short answer
Johnston, South Carolina: USDA zone 8a, about 259 days between hard freezes, across 2K acres of town.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 10
- Edgefield County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 24
- Edgefield County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~259
- Edgefield County normal — NOAA 1991–2020, nearest to this town
- Town area
- 2K 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 Edgefield County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8a is Johnston's average, not your lot's — a low corner or a tree line moves it. Against Johnston's 259-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Johnston
Each reading below is measured for Johnston itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsJohnston runs about 259 days between hard freezes (read from Edgefield County, the closest normal to Johnston) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredJohnston sits in USDA hardiness zone 8a.
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 Johnston is in
Johnston sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Johnston's own centroid, and it is not what its county reads: Edgefield County is mostly Piedmont. The wider page above you is answering a different question about different ground.
What Grows in Johnston
Every plant below cleared Johnston's own zone 8a and its 259-day season. Each card opens that plant's South Carolina profile. How we score.
Is it too late to plant in Johnston?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 24 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Johnston
Survey cells within 31 miles of Johnston checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 116 miles off. What to watch for.
What's on the federal record near Johnston
Closest first, within ~10 miles of Johnston. Listing isn't leaking, and distance isn't exposure.
- MONCKS CORNERUnderground Storage Tanks · 700 ft
- JOHNSTON SHELL STATIONUnderground Storage Tanks · 800 ft
- JOHNSTON TOWN OFUnderground Storage Tanks · 1200 ft
- PANTRY 534Underground Storage Tanks · 1300 ft
- EFC 11Underground Storage Tanks · 1500 ft
- JOHNSTON SECTION SHEDUnderground Storage Tanks · 1900 ft
- BERRYUnderground Storage Tanks · 1900 ft
- LEROY WILLIAMS GROCERYUnderground Storage Tanks · 1900 ft
- BITSYS QUICK SHOPUnderground Storage Tanks · 1900 ft
- JOHNSTON RADIO RELAY STA SC1160Underground Storage Tanks · 1900 ft
- GOLD KIST STOREUnderground Storage Tanks · 1900 ft
- J&M SERVICE CENTERUnderground Storage Tanks · 1900 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Johnston'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 Johnston.
Total Sites
130
within ~10 miles of Johnston
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Johnston
Severity Distribution
within ~10 miles of Johnston
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Johnston, two things run higher than the national average within ~10 miles of Johnston — Underground Storage Tanks (94 sites) and Toxics Release Inventory (8 sites). That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Johnston
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 Johnston average
Your land is one point inside Johnston
Everything above resolves to Johnston as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Edgefield County’s record because no 30-year normal resolves at this town’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 town 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 Johnston Average
Johnston Average
- ●USDA Zones 8a, averaged across Johnston
- ●One soil character for all of Johnston
- ●Frost dates read at Johnston's scale: Mar 10 to Nov 24
YOUR Parcel
- ✓Your exact zone, not Johnston's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Johnston
Pull a site-specific report for your exact address in Johnston, South Carolina — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Johnston averages can't show:
We read public map data around Johnston — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Johnston average
How we know this about Johnston
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Edgefield 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 town grain anywhere on this page — there is no town-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 Johnston
When does frost risk typically end in Johnston?
The last hard freeze (28°F) in Johnston typically lands around Mar 10, 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 31.
When is the first frost in Johnston?
The first hard freeze (28°F) in Johnston typically arrives around Nov 24, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 10, so the watching starts about Oct 25 — about 259 days after the spring freeze cleared.
How long is the growing season in Johnston?
Measured between 28°F hard freezes, Johnston sees about 259 frost-free days — roughly Mar 10 through Nov 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 31 to Nov 10, about 224 days.
Is the soil safe to grow vegetables in Johnston?
The federal record around Johnston is a meaningful one — 130 documented sites, mostly Underground Storage Tanks entries (94), 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.
How do I protect my plants from frost in Johnston?
From about Oct 25 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 24 (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 24. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Johnston's scale — its 8a band and its 259-day season. Your yard writes its own version of Johnston'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 Johnston’s own scale
6 of the readings below were taken at Johnston's own scale — the 1,677 acres it covers and 130 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Johnston's own USDA hardiness band, zones 8aUSDA PHZM 2023
- 130 documented contamination sites on the federal record near Johnston, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Johnston's boundary and the 1,677 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~259-day seasonGrowable Ground crop-matching engine
- Johnston sits in the Southeastern Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- Lanternfly survey cells around Johnston checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Johnston has no normal of its own, so its county's is the closest measured readfrom Edgefield County
- Soil character — no town-scale survey exists, so Johnston's 1,677 acres read through its county's SSURGO summaryfrom Edgefield County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Edgefield County
- The growing challenges every South Carolina grower plans around — written at state scale, so they stay on the state guidefrom South Carolina
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Edgefield County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Johnston's 1,677 acreswhy one lot differs from the next →
- Which side of Johnston you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,677 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Johnston-wide figureread your own land →
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