Benewah County, in Idaho, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Benewah County lies within the Idaho Panhandle (North Idaho) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Benewah County holds more than one microclimate.
Soils and elevations shift across Benewah County, so your frost dates and drainage aren't the county average. 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 Benewah County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Benewah County — the short answer
Benewah County, Idaho: USDA zone 6b, about 181 days between hard freezes, across 497K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 497K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Benewah County's average, not your lot's — a low corner or a tree line moves it. Against Benewah County's 181-day season, see what your own ground reads.
Heat in Benewah County
Across a year, Benewah County accumulates about 1,506 growing degree days above 50°F, about 15 more than the middle Idaho county — ahead of 22 of Idaho’s 44 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Benewah County
Across Benewah County, the ground is predominantly Andisols, where Honeyjones, Hobnail, and Ahrs are the most extensive named soil series. The soil is generally well drained with a ashy silt loam surface. Topsoil pH runs about 6.1–6.7, slightly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Andisols
Drainage
Well drained
Prime farmland
3%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Benewah County
The USDA soil survey maps 58% of Benewah County as well drained — but another 41% drains differently: 35% moderately well drained, 3% somewhat poorly drained.
Honeyjones is the most extensive named soil at 10% of mapped acres, then Hobnail (7%) and Ahrs (7%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Benewah County
Each reading below is measured for Benewah County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Benewah County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Benewah County runs about pH 6.1–6.7, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredBenewah County 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
MeasuredBenewah County 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 Benewah County is in
Benewah County spans 2 EPA Level III ecoregions — Northern Rockies (83%) and Columbia Plateau (17%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Benewah County
We scored all 1,086 plants against Benewah County's own USDA zone 6b and its own 181-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Idaho profile.
Is it too late to plant in Benewah County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 19 — 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 gets applied to farmland in Benewah County
USGS estimates 16,194 lb of Glyphosate on Benewah County farmland in 2019, its largest by weight, ahead of Bromoxynil (6,456 lb) and 2,4-d (3,887 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Benewah County — and how to grow with it.
We checked the federal record across Benewah County — 157 documented sites across 6 of the 9 source types we track.
The most significant on record: 3 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Benewah County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Benewah County
Closest first, across Benewah County. Listing isn't leaking, and distance isn't exposure.
- 45N 03W 26DDA1Nitrate · 1.9 mi
- 45N 03W 26CDD1Nitrate · 2.4 mi
- 45N 02W 04CDA1Nitrate · 4.1 mi
- 46N 02W 35CCD1Nitrate · 5.7 mi
- 46N 02W 19DCB1Nitrate · 6.6 mi
- 44N/02W-33BA1Nitrate · 6.6 mi
- 45N 01W 29BAD1Nitrate · 6.7 mi
- 44N 02W 28DCD1Nitrate · 6.8 mi
- 44N 03W 36BAB1Nitrate · 6.8 mi
- 46N 03W 33ABB1Nitrate · 6.8 mi
- 45N 04W 13ACD1Nitrate · 6.8 mi
- 46N 02W 36DAC1Nitrate · 6.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Benewah County'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 Benewah County.
Sources Checked
across Benewah County
Severity Distribution
across Benewah County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Benewah County, two things run higher than the national average across Benewah County — Nitrate (100 sites) and Superfund (3 sites). 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.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Benewah County
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 Benewah County average
Your land is one point inside Benewah County
Everything above resolves to Benewah County as a whole — one PHZM band and one county frost record, read across 497K 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 county 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 county average.
Your Lot vs the Benewah County Average
Benewah County Average
- ●USDA Zones 6b, averaged across Benewah County
- ●One soil character for all of Benewah County
- ●Frost dates read at Benewah County's scale: Apr 21 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Benewah County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Benewah County
Pull a site-specific report for your exact address in Benewah County, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Benewah County averages can't show:
We read public map data around Benewah County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Benewah County average
How we know this about Benewah County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Benewah County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Benewah County
When does frost risk typically end in Benewah County?
The last hard freeze (28°F) in Benewah County typically lands around Apr 21, 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 12.
How long is the growing season in Benewah County?
Measured between 28°F hard freezes, Benewah County sees about 181 frost-free days — roughly Apr 21 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Oct 5, about 146 days.
Is the soil safe to grow vegetables in Benewah County?
The federal record around Benewah County is a meaningful one — 157 documented sites, mostly Nitrate entries (100), the nearest Nitrate record about 1.9 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.
Everything above is measured at Benewah County's scale — its 6b band and its 181-day season. Your yard writes its own version of Benewah County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Idaho's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Benewah County’s own scale
8 of the readings below were taken at Benewah County's own scale — its own ~181-day span between 28°F freezes, the 3 most extensive soil series mapped here and 157 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Benewah County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Benewah County's own 28°F hard-freeze dates and its ~181-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Benewah CountyUSDA NRCS SSURGO
- 157 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 1.9 miles outFederal environmental registers
- Benewah County's boundary and the 497,236 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 2 ecoregions Benewah County spans, Northern Rockies the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Benewah County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
What this page can’t tell you
- How the season shifts across Benewah County — the ~181 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Benewah County's 497,236 acreswhy one lot differs from the next →
- Which of those 157 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Benewah Countyread your own land →