Grangeville, Idaho, 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.
Even in Grangeville, 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 Grangeville 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 Grangeville — soil, climate, flood, and parcel records. How we handle your address.
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Grangeville — the short answer
Grangeville, Idaho: USDA zone 6b, about 172 days between hard freezes, across 964 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- 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
- ~172
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 964 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 Grangeville's average, not your lot's — a low corner or a tree line moves it. Against Grangeville's 172-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grangeville
Each reading below is measured for Grangeville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrangeville runs about 172 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
MeasuredGrangeville 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 Grangeville is in
Grangeville sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. That is read at Grangeville's own centroid, and it is not what its county reads: Idaho County is mostly Idaho Batholith. The wider page above you is answering a different question about different ground.
What Grows in Grangeville
Every plant below cleared Grangeville's own zone 6b and its 172-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Grangeville?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (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 Grangeville
Closest first, within ~10 miles of Grangeville. Listing isn't leaking, and distance isn't exposure.
- BROWN MOTORS, INC.Underground Storage Tanks · 150 ft
- CLEARWATER WAREHOUSE YARDUnderground Storage Tanks · 200 ft
- #22000 GRANGEVILLE MTCE YARDUnderground Storage Tanks · 200 ft
- R GREEN & SONSUnderground Storage Tanks · 200 ft
- PUBLIC WORKS BLDGUnderground Storage Tanks · 200 ft
- BELL EQUIPMENT INCBrownfields · 300 ft
- IDAHO COUNTYUnderground Storage Tanks · 400 ft
- GORTSEMA MOTORS INCUnderground Storage Tanks · 500 ft
- GORTSEMA MOTORS INCBrownfields · 600 ft
- GRANGEVILLE ELEMENTARY & JR HIGH SCHOOLUnderground Storage Tanks · 1000 ft
- JOHN'S EXXONUnderground Storage Tanks · 1000 ft
- C H & VIRGINIA KETCHAM &Underground Storage Tanks · 1000 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Grangeville'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 Grangeville.
Total Sites
89
within ~10 miles of Grangeville
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Grangeville
Severity Distribution
within ~10 miles of Grangeville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grangeville, two things run higher than the national average within ~10 miles of Grangeville — CAFO (3 sites) and Mining (8 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Grangeville
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 Grangeville average
Your land is one point inside Grangeville
Everything above resolves to Grangeville as a whole — one PHZM band and one 28°F frost record, read across 964 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 Grangeville Average
Grangeville Average
- ●USDA Zones 6b, averaged across Grangeville
- ●One soil character for all of Grangeville
- ●Frost dates read at Grangeville's scale: Apr 28 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Grangeville's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grangeville
Pull a site-specific report for your exact address in Grangeville, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grangeville averages can't show:
We read public map data around Grangeville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grangeville average
How we know this about Grangeville
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 Grangeville’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 Grangeville
When does frost risk typically end in Grangeville?
The last hard freeze (28°F) in Grangeville typically lands around Apr 28, 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 19.
When is the first frost in Grangeville?
The first hard freeze (28°F) in Grangeville 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 172 days after the spring freeze cleared.
How long is the growing season in Grangeville?
Measured between 28°F hard freezes, Grangeville sees about 172 frost-free days — roughly Apr 28 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Oct 3, about 137 days.
Is the soil safe to grow vegetables in Grangeville?
The federal record around Grangeville is a meaningful one — 89 documented sites, mostly Underground Storage Tanks entries (37), the nearest Underground Storage Tanks record under a tenth of a mile 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 Grangeville?
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 Grangeville's scale — its 6b band and its 172-day season. Your yard writes its own version of Grangeville'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 Grangeville’s own scale
6 of the readings below were taken at Grangeville's own scale — its own ~172-day season between 28°F freezes, the 964 acres it covers and 89 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grangeville's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Grangeville's own 28°F hard-freeze dates, about Apr 28 and Oct 17 and the ~172-day span between themNOAA 1991–2020 Climate Normals
- 89 documented contamination sites on the federal record near Grangeville, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Grangeville's boundary and the 964 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~172-day seasonGrowable Ground crop-matching engine
- Grangeville sits in the Columbia Plateau — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Grangeville's 964 acres read through its county's SSURGO summaryfrom Idaho County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Idaho 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 Idaho County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grangeville's 964 acreswhy one lot differs from the next →
- Which side of Grangeville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 964 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Grangeville-wide figureread your own land →
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