Malmstrom AFB, Montana, sits in USDA hardiness zone 4b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, cranberry, turkish rocket, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Malmstrom AFB, 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 Malmstrom AFB 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 Malmstrom AFB — soil, climate, flood, and parcel records. How we handle your address.
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Malmstrom AFB — the short answer
Malmstrom AFB, Montana: USDA zone 4b, about 164 days between hard freezes, across 3K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~164
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K 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 4b is Malmstrom AFB's average, not your lot's — a low corner or a tree line moves it. Against Malmstrom AFB's 164-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Malmstrom AFB
Each reading below is measured for Malmstrom AFB itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMalmstrom AFB runs about 164 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
MeasuredMalmstrom AFB sits in USDA hardiness zone 4b.
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 Malmstrom AFB is in
Malmstrom AFB sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Malmstrom AFB's own centroid rather than borrowed from Cascade County.
What Grows in Malmstrom AFB
Every plant below cleared Malmstrom AFB's own zone 4b and its 164-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Malmstrom AFB?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 9 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Malmstrom AFB
Closest first, within ~10 miles of Malmstrom AFB. Listing isn't leaking, and distance isn't exposure.
- MALMSTROM AIR FORCE BASESuperfund · 150 ft
- JR APPLICATIONSSuperfund · 1400 ft
- US MALMSTROM AIR FORCE BASEToxics Release Inventory · 0.8 mi
- MALMSTROM AIR FORCE BASEBrownfields · 1.0 mi
- GREAT FALLS ARMED FORCES RESERVE CENTERBrownfields · 1.0 mi
- MIRACLE MILE REDEVELOPMENTBrownfields · 1.1 mi
- 3 WAY AUTO BODY INCBrownfields · 1.2 mi
- BUNDTROCKS MIRACLE MILE SERVICEUnderground Storage Tanks · 1.2 mi
- KUSTOM CITY FIBERGLASSBrownfields · 1.4 mi
- PHILLIPS 66 CO 016294Underground Storage Tanks · 1.5 mi
- AUTO WORLD INCBrownfields · 1.5 mi
- OWNER NOT DETERMINED AT THIS TIMEUnderground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Malmstrom AFB'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 Malmstrom AFB.
Sources Checked
within ~10 miles of Malmstrom AFB
Severity Distribution
within ~10 miles of Malmstrom AFB
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Malmstrom AFB
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 Malmstrom AFB average
Your land is one point inside Malmstrom AFB
Everything above resolves to Malmstrom AFB as a whole — one PHZM band and one 28°F frost record, read across 3K 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 Malmstrom AFB Average
Malmstrom AFB Average
- ●USDA Zones 4b, averaged across Malmstrom AFB
- ●One soil character for all of Malmstrom AFB
- ●Frost dates read at Malmstrom AFB's scale: Apr 28 to Oct 9
YOUR Parcel
- ✓Your exact zone, not Malmstrom AFB's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Malmstrom AFB
Pull a site-specific report for your exact address in Malmstrom AFB, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Malmstrom AFB averages can't show:
We read public map data around Malmstrom AFB — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Malmstrom AFB average
How we know this about Malmstrom AFB
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 Malmstrom AFB’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 Malmstrom AFB
When does frost risk typically end in Malmstrom AFB?
The last hard freeze (28°F) in Malmstrom AFB typically lands around Apr 28, 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 19.
When is the first frost in Malmstrom AFB?
The first hard freeze (28°F) in Malmstrom AFB typically arrives around Oct 9, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 25, so the watching starts about Sep 9 — about 164 days after the spring freeze cleared.
How long is the growing season in Malmstrom AFB?
Measured between 28°F hard freezes, Malmstrom AFB sees about 164 frost-free days — roughly Apr 28 through Oct 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Sep 25, about 129 days.
Is the soil safe to grow vegetables in Malmstrom AFB?
The federal record around Malmstrom AFB is a meaningful one — 446 documented sites, mostly Underground Storage Tanks entries (271), the nearest Superfund 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 Malmstrom AFB?
From about Sep 9 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 9 (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 9. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Malmstrom AFB's scale — its 4b band and its 164-day season. Your yard writes its own version of Malmstrom AFB'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 Malmstrom AFB’s own scale
6 of the readings below were taken at Malmstrom AFB's own scale — its own ~164-day season between 28°F freezes, the 3,268 acres it covers and 446 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Malmstrom AFB's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Malmstrom AFB's own 28°F hard-freeze dates, about Apr 28 and Oct 9 and the ~164-day span between themNOAA 1991–2020 Climate Normals
- 446 documented contamination sites on the federal record near Malmstrom AFB, the closest Superfund record under a tenth of a mile out from the town centreFederal environmental registers
- Malmstrom AFB's boundary and the 3,268 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~164-day seasonGrowable Ground crop-matching engine
- The ecoregion at Malmstrom AFB's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Malmstrom AFB's 3,268 acres read through its county's SSURGO summaryfrom Cascade County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Cascade 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 Cascade County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Malmstrom AFB's 3,268 acreswhy one lot differs from the next →
- Which side of Malmstrom AFB you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,268 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Superfund 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 Malmstrom AFB-wide figureread your own land →