Bigfork, Montana, sits in USDA hardiness zone 5b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Expect cabbage, cranberry, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Bigfork, 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 Bigfork 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 Bigfork — soil, climate, flood, and parcel records. How we handle your address.
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Bigfork — the short answer
Bigfork, Montana: USDA zone 5b, about 161 days between hard freezes, across 20K acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~161
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 20K 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 Bigfork's average, not your lot's — a low corner or a tree line moves it. Against Bigfork's 161-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bigfork
Each reading below is measured for Bigfork itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBigfork runs about 161 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
MeasuredBigfork 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 Bigfork is in
Bigfork sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Bigfork's own centroid, and it is not what its county reads: Flathead County is mostly Canadian Rockies. The wider page above you is answering a different question about different ground.
What Grows in Bigfork
Every plant below cleared Bigfork's own zone 5b and its 161-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Bigfork?
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 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — 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 Bigfork
Closest first, within ~10 miles of Bigfork. Listing isn't leaking, and distance isn't exposure.
- KAY GB PROPERTIES LLCUnderground Storage Tanks · 1.3 mi
- WOODS BAY SERVICE & RV PARKUnderground Storage Tanks · 1.3 mi
- MDOT BIGFORK MAINTENANCE SITEUnderground Storage Tanks · 1.3 mi
- CALUMET CARDLOCKUnderground Storage Tanks · 1.3 mi
- BIGFORK OUTDOOR RENTALS INCUnderground Storage Tanks · 1.4 mi
- BIGFORK STAGE STOP INCUnderground Storage Tanks · 1.7 mi
- YOUR TURN CONVENIENCE STOPUnderground Storage Tanks · 1.7 mi
- PACIFICORP TRANSFORMER YARDSuperfund · 1.9 mi
- BIGFORK WATER AND SEWER DISTRICTUnderground Storage Tanks · 1.9 mi
- CURTIS & CURTIS CONSTRUCTIONUnderground Storage Tanks · 1.9 mi
- MONTANA RANCH LLCUnderground Storage Tanks · 2.0 mi
- BAY AUTOMOTIVEBrownfields · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Bigfork'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 Bigfork.
Total Sites
83
within ~10 miles of Bigfork
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Bigfork
Severity Distribution
within ~10 miles of Bigfork
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bigfork, Nitrate runs higher than the national average — 36 sites within ~10 miles of Bigfork. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 Bigfork
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 Bigfork average
Your land is one point inside Bigfork
Everything above resolves to Bigfork as a whole — one PHZM band and one 28°F frost record, read across 20K 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 town 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 Bigfork Average
Bigfork Average
- ●USDA Zones 5b, averaged across Bigfork
- ●One soil character for all of Bigfork
- ●Frost dates read at Bigfork's scale: Apr 29 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Bigfork's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bigfork
Pull a site-specific report for your exact address in Bigfork, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bigfork averages can't show:
We read public map data around Bigfork — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bigfork average
How we know this about Bigfork
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Bigfork’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 town grain anywhere on this page — there is no town-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 Bigfork
When does frost risk typically end in Bigfork?
The last hard freeze (28°F) in Bigfork typically lands around Apr 29, 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 20.
When is the first frost in Bigfork?
The first hard freeze (28°F) in Bigfork typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 161 days after the spring freeze cleared.
How long is the growing season in Bigfork?
Measured between 28°F hard freezes, Bigfork sees about 161 frost-free days — roughly Apr 29 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 20 to Sep 23, about 126 days.
Is the soil safe to grow vegetables in Bigfork?
The federal record around Bigfork is a meaningful one — 83 documented sites, mostly Underground Storage Tanks entries (42), the nearest Underground Storage Tanks record about 1.3 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 Bigfork?
From about Sep 7 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 7 (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 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Bigfork's scale — its 5b band and its 161-day season. Your yard writes its own version of Bigfork'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 Bigfork’s own scale
6 of the readings below were taken at Bigfork's own scale — its own ~161-day season between 28°F freezes, the 20,003 acres it covers and 83 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Bigfork's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Bigfork's own 28°F hard-freeze dates, about Apr 29 and Oct 7 and the ~161-day span between themNOAA 1991–2020 Climate Normals
- 83 documented contamination sites on the federal record near Bigfork, the closest Underground Storage Tanks record about 1.3 miles out from the town centreFederal environmental registers
- Bigfork's boundary and the 20,003 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~161-day seasonGrowable Ground crop-matching engine
- Bigfork sits in the Northern Rockies — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Bigfork's 20,003 acres read through its county's SSURGO summaryfrom Flathead County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Flathead County
- The growing challenges every Montana grower plans around — written at state scale, so they stay on the state guidefrom Montana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Flathead County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bigfork's 20,003 acreswhy one lot differs from the next →
- Which side of Bigfork you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 20,003 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.3 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 Bigfork-wide figureread your own land →
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