Smelterville, Idaho, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include cabbage, blackberry, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Smelterville, 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 Smelterville 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 Smelterville — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Smelterville — the short answer
Smelterville, Idaho: USDA zone 6b, about 181 days between hard freezes, across 196 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 196 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 6b is Smelterville's average, not your lot's — a low corner or a tree line moves it. Against Smelterville's 181-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Smelterville
Each reading below is measured for Smelterville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSmelterville runs about 181 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
MeasuredSmelterville 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 Smelterville is in
Smelterville sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Smelterville's own centroid rather than borrowed from Shoshone County.
What Grows in Smelterville
Every plant below cleared Smelterville's own zone 6b and its 181-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Smelterville?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Smelterville
Closest first, within ~10 miles of Smelterville. Listing isn't leaking, and distance isn't exposure.
- O. K. ProspectMining · 1500 ft
- O.K. ProspectMining · 1500 ft
- SHOSHONE COUNTY 2Underground Storage Tanks · 1600 ft
- WHEELS/ BRAD EATONUnderground Storage Tanks · 1900 ft
- WALMART SUPERCENTER #4249Brownfields · 2400 ft
- SVL ANALYTICAL INCBrownfields · 2400 ft
- BH-SF-W-0016-U-South Fork West-Transect 5 to Mid-SmeltervillNitrate · 2500 ft
- BH-GG-GW-0004-South Fork East-Government GulchNitrate · 2600 ft
- BH-GG-GW-0006-South Fork East-Government GulchNitrate · 2600 ft
- BH-GG-GW-0005-South Fork East-Government GulchNitrate · 2600 ft
- SILVER VALLEY TRUCK STOPUnderground Storage Tanks · 0.5 mi
- BH-SF-E-0517-UNitrate · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Smelterville'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 Smelterville.
Sources Checked
within ~10 miles of Smelterville
Severity Distribution
within ~10 miles of Smelterville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Smelterville, two things run higher than the national average within ~10 miles of Smelterville — Mining (232 sites) and Nitrate (262 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.
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 Smelterville
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 Smelterville average
Your land is one point inside Smelterville
Everything above resolves to Smelterville as a whole — one PHZM band and one 28°F frost record, read across 196 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 city 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 Smelterville Average
Smelterville Average
- ●USDA Zones 6b, averaged across Smelterville
- ●One soil character for all of Smelterville
- ●Frost dates read at Smelterville's scale: Apr 19 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Smelterville's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Smelterville
Pull a site-specific report for your exact address in Smelterville, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Smelterville averages can't show:
We read public map data around Smelterville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Smelterville average
How we know this about Smelterville
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Smelterville’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 city grain anywhere on this page — there is no city-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 Smelterville
When does frost risk typically end in Smelterville?
The last hard freeze (28°F) in Smelterville typically lands around Apr 19, 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 10.
When is the first frost in Smelterville?
The first hard freeze (28°F) in Smelterville typically arrives around Oct 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 3, so the watching starts about Sep 17 — about 181 days after the spring freeze cleared.
How long is the growing season in Smelterville?
Measured between 28°F hard freezes, Smelterville sees about 181 frost-free days — roughly Apr 19 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 10 to Oct 3, about 146 days.
Is the soil safe to grow vegetables in Smelterville?
The federal record around Smelterville runs heavier than most — 572 documented sites, mostly Nitrate entries (262), the nearest Mining record about 0.3 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 Smelterville?
From about Sep 17 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Smelterville's scale — its 6b band and its 181-day season. Your yard writes its own version of Smelterville'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 Smelterville’s own scale
6 of the readings below were taken at Smelterville's own scale — its own ~181-day season between 28°F freezes, the 196 acres it covers and 572 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Smelterville's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Smelterville's own 28°F hard-freeze dates, about Apr 19 and Oct 17 and the ~181-day span between themNOAA 1991–2020 Climate Normals
- 572 documented contamination sites on the federal record near Smelterville, the closest Mining record about 0.3 miles out from the town centreFederal environmental registers
- Smelterville's boundary and the 196 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~181-day seasonGrowable Ground crop-matching engine
- The ecoregion at Smelterville's own centroid, the Northern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Smelterville's 196 acres read through its county's SSURGO summaryfrom Shoshone County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Shoshone County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Shoshone County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Smelterville's 196 acreswhy one lot differs from the next →
- Which side of Smelterville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 196 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.3 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 Smelterville-wide figureread your own land →
More in Idaho
Growing region