Charleston, Utah, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
These conditions suit cabbage, blackberry, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Charleston, 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 Charleston 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 Charleston — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Charleston — the short answer
Charleston, Utah: USDA zone 6a, about 153 days between hard freezes, across 2K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~153
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 6a is Charleston's average, not your lot's — a low corner or a tree line moves it. Against Charleston's 153-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Charleston
Each reading below is measured for Charleston itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCharleston runs about 153 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
MeasuredCharleston sits in USDA hardiness zone 6a.
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 Charleston is in
Charleston sits in the Wasatch and Uinta Mountains — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Charleston's own centroid rather than borrowed from Wasatch County.
What Grows in Charleston
Every plant below cleared Charleston's own zone 6a and its 153-day season. Each card opens that plant's Utah profile. How we score.
Is it too late to plant in Charleston?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 5 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Charleston
Spotted lanternfly documented 10 miles from Charleston, first recorded 2020. What to watch for.
What's on the federal record near Charleston
Closest first, within ~10 miles of Charleston. Listing isn't leaking, and distance isn't exposure.
- BROADHEAD FEEDLOTCAFO · 2600 ft
- CHARLESTON CITY GARAGEUnderground Storage Tanks · 0.5 mi
- ELMER ANDREASON WELL (100 FEET DEEP)Nitrate · 0.5 mi
- (D- 4- 4)13cba- 1Nitrate · 0.6 mi
- STAKER PARSON MATERIALS & CONSTRUCTION - HEBER BINGGELI PITToxics Release Inventory · 0.6 mi
- REED EDWARDS WELL (30 FEET DEEP)Nitrate · 0.6 mi
- CHARLESTON TOWN WELL (325 FEET DEEP)Nitrate · 0.7 mi
- JOHN L JACOBSEN WELL (27 FEET DEEP)Nitrate · 0.7 mi
- CHARLESTON NORTH MERCUnderground Storage Tanks · 0.7 mi
- MARLO EDWARDS WELL (18 FEET DEEP)Nitrate · 0.8 mi
- HEBER VALLEY SSD WELL (85 FEET DEEP)Nitrate · 1.0 mi
- (D- 4- 4)10daa- 2Nitrate · 1.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Charleston'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 Charleston.
Total Sites
275
within ~10 miles of Charleston
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Charleston
Severity Distribution
within ~10 miles of Charleston
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Charleston, two things run higher than the national average within ~10 miles of Charleston — Mining (61 sites) and Nitrate (148 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Charleston
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 Charleston average
Your land is one point inside Charleston
Everything above resolves to Charleston as a whole — one PHZM band and one 28°F frost record, read across 2K 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 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 Charleston Average
Charleston Average
- ●USDA Zones 6a, averaged across Charleston
- ●One soil character for all of Charleston
- ●Frost dates read at Charleston's scale: May 5 to Oct 5
YOUR Parcel
- ✓Your exact zone, not Charleston's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Charleston
Pull a site-specific report for your exact address in Charleston, Utah — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Charleston averages can't show:
We read public map data around Charleston — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Charleston average
How we know this about Charleston
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 Charleston’s own record; 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 Charleston
When does frost risk typically end in Charleston?
The last hard freeze (28°F) in Charleston typically lands around May 5, 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 26.
When is the first frost in Charleston?
The first hard freeze (28°F) in Charleston typically arrives around Oct 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 21, so the watching starts about Sep 5 — about 153 days after the spring freeze cleared.
How long is the growing season in Charleston?
Measured between 28°F hard freezes, Charleston sees about 153 frost-free days — roughly May 5 through Oct 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Sep 21, about 118 days.
Is the soil safe to grow vegetables in Charleston?
The federal record around Charleston runs heavier than most — 275 documented sites, mostly Nitrate entries (148), the nearest CAFO record about 0.5 miles out — 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 Charleston?
From about Sep 5 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 Oct 5 (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 Oct 5. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Charleston's scale — its 6a band and its 153-day season. Your yard writes its own version of Charleston'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 Charleston’s own scale
7 of the readings below were taken at Charleston's own scale — its own ~153-day season between 28°F freezes, the 1,934 acres it covers and 275 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Charleston's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Charleston's own 28°F hard-freeze dates, about May 5 and Oct 5 and the ~153-day span between themNOAA 1991–2020 Climate Normals
- 275 documented contamination sites on the federal record near Charleston, the closest CAFO record about 0.5 miles out from the town centreFederal environmental registers
- Charleston's boundary and the 1,934 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~153-day seasonGrowable Ground crop-matching engine
- The ecoregion at Charleston's own centroid, the Wasatch and Uinta MountainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Charlestonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Charleston's 1,934 acres read through its county's SSURGO summaryfrom Wasatch County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Wasatch County
- The growing challenges every Utah grower plans around — written at state scale, so they stay on the state guidefrom Utah
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Wasatch County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Charleston's 1,934 acreswhy one lot differs from the next →
- Which side of Charleston you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,934 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest CAFO record about 0.5 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 Charleston-wide figureread your own land →