Athol, Idaho, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
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 Athol, 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 Athol 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 Athol — soil, climate, flood, and parcel records. How we handle your address.
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Athol — the short answer
Athol, Idaho: USDA zone 6b, about 168 days between hard freezes, across 735 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~168
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 735 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 Athol's average, not your lot's — a low corner or a tree line moves it. Against Athol's 168-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Athol
Each reading below is measured for Athol itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAthol runs about 168 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
MeasuredAthol 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 Athol is in
Athol sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Athol's own centroid rather than borrowed from Kootenai County.
What Grows in Athol
Every plant below cleared Athol's own zone 6b and its 168-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Athol?
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 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Athol
Closest first, within ~10 miles of Athol. Listing isn't leaking, and distance isn't exposure.
- MERRITT BROTHERS LUMBERToxics Release Inventory · 1000 ft
- 53N 03W 09CDD1Nitrate · 1100 ft
- IDAHO FOREST GROUP - ATHOLBrownfields · 1200 ft
- A&J FOOD STORE INC/CROSSROADS EXPRESS INCUnderground Storage Tanks · 1900 ft
- ATHOL ELEMENTARY SCHOOLUnderground Storage Tanks · 2000 ft
- Love's Trading PostUnderground Storage Tanks · 0.5 mi
- JERRY A LONGUnderground Storage Tanks · 1.6 mi
- SHAMROCK RANCHUnderground Storage Tanks · 1.9 mi
- 53N 03W 03BAB1Nitrate · 2.2 mi
- SILVERWOOD INCUnderground Storage Tanks · 2.6 mi
- SCHOONY'S TRUCK STOPUnderground Storage Tanks · 2.9 mi
- 53N 03W 30BAA1Nitrate · 3.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Athol'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 Athol.
Total Sites
97
within ~10 miles of Athol
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Athol
Severity Distribution
within ~10 miles of Athol
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Athol, two things run higher than the national average within ~10 miles of Athol — Mining (11 sites) and Nitrate (44 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 Athol
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 Athol average
Your land is one point inside Athol
Everything above resolves to Athol as a whole — one PHZM band and one 28°F frost record, read across 735 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 Athol Average
Athol Average
- ●USDA Zones 6b, averaged across Athol
- ●One soil character for all of Athol
- ●Frost dates read at Athol's scale: Apr 26 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Athol's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Athol
Pull a site-specific report for your exact address in Athol, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Athol averages can't show:
We read public map data around Athol — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Athol average
How we know this about Athol
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 Athol’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 Athol
When does frost risk typically end in Athol?
The last hard freeze (28°F) in Athol typically lands around Apr 26, 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 17.
When is the first frost in Athol?
The first hard freeze (28°F) in Athol typically arrives around Oct 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 27, so the watching starts about Sep 11 — about 168 days after the spring freeze cleared.
How long is the growing season in Athol?
Measured between 28°F hard freezes, Athol sees about 168 frost-free days — roughly Apr 26 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 17 to Sep 27, about 133 days.
Is the soil safe to grow vegetables in Athol?
The federal record around Athol is a meaningful one — 97 documented sites, mostly Nitrate entries (44), the nearest Toxics Release Inventory record about 0.2 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.
How do I protect my plants from frost in Athol?
From about Sep 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Athol's scale — its 6b band and its 168-day season. Your yard writes its own version of Athol'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 Athol’s own scale
6 of the readings below were taken at Athol's own scale — its own ~168-day season between 28°F freezes, the 735 acres it covers and 97 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Athol's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Athol's own 28°F hard-freeze dates, about Apr 26 and Oct 11 and the ~168-day span between themNOAA 1991–2020 Climate Normals
- 97 documented contamination sites on the federal record near Athol, the closest Toxics Release Inventory record about 0.2 miles out from the town centreFederal environmental registers
- Athol's boundary and the 735 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~168-day seasonGrowable Ground crop-matching engine
- The ecoregion at Athol's own centroid, the Northern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Athol's 735 acres read through its county's SSURGO summaryfrom Kootenai County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kootenai 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 Kootenai County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Athol's 735 acreswhy one lot differs from the next →
- Which side of Athol you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 735 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Toxics Release Inventory record about 0.2 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 Athol-wide figureread your own land →
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