Columbia Falls, Montana, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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 Columbia Falls, 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 Columbia Falls 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 Columbia Falls — soil, climate, flood, and parcel records. How we handle your address.
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Columbia Falls — the short answer
Columbia Falls, Montana: USDA zone 5a, about 150 days between hard freezes, across 1K acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~150
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 1K 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 5a is Columbia Falls's average, not your lot's — a low corner or a tree line moves it. Against Columbia Falls's 150-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Columbia Falls
Each reading below is measured for Columbia Falls itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredColumbia Falls runs about 150 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
MeasuredColumbia Falls sits in USDA hardiness zone 5a.
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 Columbia Falls is in
Columbia Falls sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Columbia Falls'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 Columbia Falls
Every plant below cleared Columbia Falls's own zone 5a and its 150-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Columbia Falls?
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 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 2 — 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 Columbia Falls
Closest first, within ~10 miles of Columbia Falls. Listing isn't leaking, and distance isn't exposure.
- COLUMBIA FALLS COIN OPUnderground Storage Tanks · 300 ft
- CITY SHOP SITEUnderground Storage Tanks · 450 ft
- DALENS DIESEL SERVICE INCBrownfields · 500 ft
- SPECIAL EFFECTS AUTO PAINTINGBrownfields · 500 ft
- RONS CORNER STOPUnderground Storage Tanks · 550 ft
- MDOT COLUMBIA FALLSUnderground Storage Tanks · 550 ft
- BN MICROWAVE SITEUnderground Storage Tanks · 550 ft
- TOWN PUMP INC COLUMBIA FALLS 1Underground Storage Tanks · 700 ft
- COLUMBIA FALLS HIGH SCHOOLBrownfields · 950 ft
- CLEAN KARSUnderground Storage Tanks · 1200 ft
- F & C AUTOUnderground Storage Tanks · 1200 ft
- WEYERHAEUSER NR- COLUMBIA FALLSBrownfields · 1500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Columbia Falls'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 Columbia Falls.
Sources Checked
within ~10 miles of Columbia Falls
Severity Distribution
within ~10 miles of Columbia Falls
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Columbia Falls, two things run higher than the national average within ~10 miles of Columbia Falls — Superfund (3 sites) and Nitrate (52 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Columbia Falls
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 Columbia Falls average
Your land is one point inside Columbia Falls
Everything above resolves to Columbia Falls as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Columbia Falls Average
Columbia Falls Average
- ●USDA Zones 5a, averaged across Columbia Falls
- ●One soil character for all of Columbia Falls
- ●Frost dates read at Columbia Falls's scale: May 5 to Oct 2
YOUR Parcel
- ✓Your exact zone, not Columbia Falls's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Columbia Falls
Pull a site-specific report for your exact address in Columbia Falls, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Columbia Falls averages can't show:
We read public map data around Columbia Falls — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Columbia Falls average
How we know this about Columbia Falls
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 Columbia Falls’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 Columbia Falls
When does frost risk typically end in Columbia Falls?
The last hard freeze (28°F) in Columbia Falls typically lands around May 5, 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 26.
When is the first frost in Columbia Falls?
The first hard freeze (28°F) in Columbia Falls typically arrives around Oct 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 18, so the watching starts about Sep 2 — about 150 days after the spring freeze cleared.
How long is the growing season in Columbia Falls?
Measured between 28°F hard freezes, Columbia Falls sees about 150 frost-free days — roughly May 5 through Oct 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Sep 18, about 115 days.
Is the soil safe to grow vegetables in Columbia Falls?
The federal record around Columbia Falls is a meaningful one — 196 documented sites, mostly Underground Storage Tanks entries (97), 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 Columbia Falls?
From about Sep 2 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 2 (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 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Columbia Falls's scale — its 5a band and its 150-day season. Your yard writes its own version of Columbia Falls'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 Columbia Falls’s own scale
6 of the readings below were taken at Columbia Falls's own scale — its own ~150-day season between 28°F freezes, the 1,460 acres it covers and 196 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Columbia Falls's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Columbia Falls's own 28°F hard-freeze dates, about May 5 and Oct 2 and the ~150-day span between themNOAA 1991–2020 Climate Normals
- 196 documented contamination sites on the federal record near Columbia Falls, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Columbia Falls's boundary and the 1,460 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~150-day seasonGrowable Ground crop-matching engine
- Columbia Falls 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 Columbia Falls's 1,460 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 Columbia Falls's 1,460 acreswhy one lot differs from the next →
- Which side of Columbia Falls you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,460 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 Columbia Falls-wide figureread your own land →
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