Big Sky Colony, Montana, sits in USDA hardiness zone 4a — a zone band wide enough that plant choice, not possibility, is the interesting question.
These conditions suit cabbage, cranberry, cilantro, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Big Sky Colony, 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 Big Sky Colony 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 Big Sky Colony — soil, climate, flood, and parcel records. How we handle your address.
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Big Sky Colony — the short answer
Big Sky Colony, Montana: USDA zone 4a, about 142 days between hard freezes, across 156 acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~142
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 156 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 4a is Big Sky Colony's average, not your lot's — a low corner or a tree line moves it. Against Big Sky Colony's 142-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Big Sky Colony
Each reading below is measured for Big Sky Colony itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBig Sky Colony runs about 142 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredBig Sky Colony sits in USDA hardiness zone 4a.
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 Big Sky Colony is in
Big Sky Colony sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Big Sky Colony's own centroid rather than borrowed from Glacier County.
What Grows in Big Sky Colony
Every plant below cleared Big Sky Colony's own zone 4a and its 142-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Big Sky Colony?
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 Apr 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 26 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What's on the federal record near Big Sky Colony
Closest first, within ~10 miles of Big Sky Colony. Listing isn't leaking, and distance isn't exposure.
- BIG SKY COLONY CAFO/AFOCAFO · 0.6 mi
- 36N09W12DDBB01Nitrate · 4.1 mi
- DEL BONITA RADAR STATION FORMERUnderground Storage Tanks · 7.2 mi
- TUCSON/HEBREW ACADEMYSuperfund · 7.2 mi
- FRANK & FAY MANLEYUnderground Storage Tanks · 7.8 mi
- 34N09W10CCAB01Nitrate · 8.6 mi
Measured from Big Sky Colony'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 Big Sky Colony.
Total Sites
8
within ~10 miles of Big Sky Colony
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Big Sky Colony
Severity Distribution
within ~10 miles of Big Sky Colony
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Large animal operations push nitrates and bacteria downstream. Below one, test your water.
Check your specific parcel in Big Sky Colony
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 Big Sky Colony average
Your land is one point inside Big Sky Colony
Everything above resolves to Big Sky Colony as a whole — one PHZM band and one 28°F frost record, read across 156 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 Big Sky Colony Average
Big Sky Colony Average
- ●USDA Zones 4a, averaged across Big Sky Colony
- ●One soil character for all of Big Sky Colony
- ●Frost dates read at Big Sky Colony's scale: May 7 to Sep 26
YOUR Parcel
- ✓Your exact zone, not Big Sky Colony's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Big Sky Colony
Pull a site-specific report for your exact address in Big Sky Colony, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Big Sky Colony averages can't show:
We read public map data around Big Sky Colony — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Big Sky Colony average
How we know this about Big Sky Colony
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 Big Sky Colony’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 Big Sky Colony
When does frost risk typically end in Big Sky Colony?
The last hard freeze (28°F) in Big Sky Colony typically lands around May 7, 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 28.
When is the first frost in Big Sky Colony?
The first hard freeze (28°F) in Big Sky Colony typically arrives around Sep 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 12, so the watching starts about Aug 27 — about 142 days after the spring freeze cleared.
How long is the growing season in Big Sky Colony?
Measured between 28°F hard freezes, Big Sky Colony sees about 142 frost-free days — roughly May 7 through Sep 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 12, about 107 days.
Is the soil safe to grow vegetables in Big Sky Colony?
The federal record around Big Sky Colony is a meaningful one — 8 documented sites, mostly Nitrate entries (4), the nearest CAFO record about 0.6 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 gardeners stretch the season in Big Sky Colony?
With about 142 frost-free days between hard freezes, Big Sky Colony rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 170 to 198 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 7 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Big Sky Colony's scale — its 4a band and its 142-day season. Your yard writes its own version of Big Sky Colony'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 Big Sky Colony’s own scale
6 of the readings below were taken at Big Sky Colony's own scale — its own ~142-day season between 28°F freezes, the 156 acres it covers and 8 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Big Sky Colony's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Big Sky Colony's own 28°F hard-freeze dates, about May 7 and Sep 26 and the ~142-day span between themNOAA 1991–2020 Climate Normals
- 8 documented contamination sites on the federal record near Big Sky Colony, the closest CAFO record about 0.6 miles out from the town centreFederal environmental registers
- Big Sky Colony's boundary and the 156 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~142-day seasonGrowable Ground crop-matching engine
- The ecoregion at Big Sky Colony's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Big Sky Colony's 156 acres read through its county's SSURGO summaryfrom Glacier County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Glacier 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 Glacier County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Big Sky Colony's 156 acreswhy one lot differs from the next →
- Which side of Big Sky Colony you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 156 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest CAFO record about 0.6 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 Big Sky Colony-wide figureread your own land →