Dubois, Idaho, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, cranberry, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Dubois, 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 Dubois 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 Dubois — soil, climate, flood, and parcel records. How we handle your address.
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Dubois — the short answer
Dubois, Idaho: USDA zone 5b, about 143 days between hard freezes, across 2K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~143
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City 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 5b is Dubois's average, not your lot's — a low corner or a tree line moves it. Against Dubois's 143-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Dubois
Each reading below is measured for Dubois itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDubois runs about 143 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredDubois sits in USDA hardiness zone 5b.
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 Dubois is in
Dubois sits in the Snake River Plain — EPA Level III, inside the wider North American Deserts. That is read at Dubois's own centroid, and it is not what its county reads: Clark County is mostly Middle Rockies. The wider page above you is answering a different question about different ground.
What Grows in Dubois
Every plant below cleared Dubois's own zone 5b and its 143-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Dubois?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 1 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What's on the federal record near Dubois
Closest first, within ~10 miles of Dubois. Listing isn't leaking, and distance isn't exposure.
- CLARK COUNTY SCHOOL DIST #161Underground Storage Tanks · 350 ft
- KILGORE STOREUnderground Storage Tanks · 1500 ft
- DUBOIS RMLR (DBS)Underground Storage Tanks · 1500 ft
- Clark County Kilgore ShedUnderground Storage Tanks · 1600 ft
- DUBOIS SECTIONUnderground Storage Tanks · 1600 ft
- USDA-AGRICULTURAL RESEARCH SERVICEUnderground Storage Tanks · 1600 ft
- CONOCO SELF SERVICEUnderground Storage Tanks · 2000 ft
- C Blaine WaringUnderground Storage Tanks · 2000 ft
- Clark County Road & Bridge ShopUnderground Storage Tanks · 2100 ft
- MRS L E HODGESUnderground Storage Tanks · 2100 ft
- ITD DUBOIS MAINTENANCE YARDUnderground Storage Tanks · 2100 ft
- 10N 36E 21CAD2Nitrate · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Dubois'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 Dubois.
Total Sites
51
within ~10 miles of Dubois
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Dubois
Severity Distribution
within ~10 miles of Dubois
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dubois, Nitrate runs higher than the national average — 28 sites within ~10 miles of Dubois. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Dubois
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 Dubois average
Your land is one point inside Dubois
Everything above resolves to Dubois 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 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 Dubois Average
Dubois Average
- ●USDA Zones 5b, averaged across Dubois
- ●One soil character for all of Dubois
- ●Frost dates read at Dubois's scale: May 11 to Oct 1
YOUR Parcel
- ✓Your exact zone, not Dubois's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dubois
Pull a site-specific report for your exact address in Dubois, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dubois averages can't show:
We read public map data around Dubois — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dubois average
How we know this about Dubois
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 Dubois’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 Dubois
When does frost risk typically end in Dubois?
The last hard freeze (28°F) in Dubois typically lands around May 11, 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 Jun 1.
When is the first frost in Dubois?
The first hard freeze (28°F) in Dubois typically arrives around Oct 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 17, so the watching starts about Sep 1 — about 143 days after the spring freeze cleared.
How long is the growing season in Dubois?
Measured between 28°F hard freezes, Dubois sees about 143 frost-free days — roughly May 11 through Oct 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 1 to Sep 17, about 108 days.
Is the soil safe to grow vegetables in Dubois?
The federal record around Dubois is a meaningful one — 51 documented sites, mostly Nitrate entries (28), 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 gardeners stretch the season in Dubois?
With about 143 frost-free days between hard freezes, Dubois rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 171 to 199 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 11 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Dubois's scale — its 5b band and its 143-day season. Your yard writes its own version of Dubois'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 Dubois’s own scale
6 of the readings below were taken at Dubois's own scale — its own ~143-day season between 28°F freezes, the 1,746 acres it covers and 51 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Dubois's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Dubois's own 28°F hard-freeze dates, about May 11 and Oct 1 and the ~143-day span between themNOAA 1991–2020 Climate Normals
- 51 documented contamination sites on the federal record near Dubois, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Dubois's boundary and the 1,746 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~143-day seasonGrowable Ground crop-matching engine
- Dubois sits in the Snake River Plain — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Dubois's 1,746 acres read through its county's SSURGO summaryfrom Clark County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Clark 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 Clark County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Dubois's 1,746 acreswhy one lot differs from the next →
- Which side of Dubois you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,746 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 Dubois-wide figureread your own land →