Butte-Silver Bow, Montana, sits in USDA hardiness zone 4a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include okra, cranberry, cilantro, and zucchini — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Butte-Silver Bow, 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 Butte-Silver Bow 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 Butte-Silver Bow — soil, climate, flood, and parcel records. How we handle your address.
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Butte-Silver Bow — the short answer
Butte-Silver Bow, Montana: USDA zone 4a, about 119 days between hard freezes, across 458K acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~119
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 458K 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 Butte-Silver Bow's average, not your lot's — a low corner or a tree line moves it. Against Butte-Silver Bow's 119-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Butte-Silver Bow
Each reading below is measured for Butte-Silver Bow itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredButte-Silver Bow runs about 119 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
MeasuredButte-Silver Bow 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 Butte-Silver Bow is in
Butte-Silver Bow sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Butte-Silver Bow's own centroid rather than borrowed from Silver Bow County.
What Grows in Butte-Silver Bow
Every plant below cleared Butte-Silver Bow's own zone 4a and its 119-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Butte-Silver Bow?
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 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 17 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.
What's on the federal record near Butte-Silver Bow
Closest first, within ~10 miles of Butte-Silver Bow. Listing isn't leaking, and distance isn't exposure.
- FEDERAL AVIATION ADMIN VORTACUnderground Storage Tanks · 2400 ft
- Gold Chief LodeMining · 1.0 mi
- BN BUTTE HOMESTAKE PASSUnderground Storage Tanks · 3.1 mi
- UNION PACIFIC RAILROAD SILVERBOWUnderground Storage Tanks · 3.1 mi
- ROBERT E CHAMBERLINUnderground Storage Tanks · 3.3 mi
- SOLVAY - SILVER BOW PLANTBrownfields · 3.6 mi
- SOLVAY - SILVER BOW PLANTToxics Release Inventory · 3.6 mi
- D J MINERAL KIT CO JOHNSONUnderground Storage Tanks · 4.3 mi
- 02N08W35ACDD01Nitrate · 5.2 mi
- Best Hope MineMining · 5.5 mi
- REC ADVANCED SILICON MATERIALS LLCBrownfields · 5.6 mi
- REC ADVANCED SILICON MATERIALS LLCToxics Release Inventory · 5.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Butte-Silver Bow'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 Butte-Silver Bow.
Sources Checked
within ~10 miles of Butte-Silver Bow
Severity Distribution
within ~10 miles of Butte-Silver Bow
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Butte-Silver Bow, two things run higher than the national average within ~10 miles of Butte-Silver Bow — Mining (57 sites) and Superfund (5 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Butte-Silver Bow
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 Butte-Silver Bow average
Your land is one point inside Butte-Silver Bow
Everything above resolves to Butte-Silver Bow as a whole — one PHZM band and one 28°F frost record, read across 458K 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 Butte-Silver Bow Average
Butte-Silver Bow Average
- ●USDA Zones 4a, averaged across Butte-Silver Bow
- ●One soil character for all of Butte-Silver Bow
- ●Frost dates read at Butte-Silver Bow's scale: May 21 to Sep 17
YOUR Parcel
- ✓Your exact zone, not Butte-Silver Bow's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Butte-Silver Bow
Pull a site-specific report for your exact address in Butte-Silver Bow, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Butte-Silver Bow averages can't show:
We read public map data around Butte-Silver Bow — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Butte-Silver Bow average
How we know this about Butte-Silver Bow
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 Butte-Silver Bow’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 Butte-Silver Bow
When does frost risk typically end in Butte-Silver Bow?
The last hard freeze (28°F) in Butte-Silver Bow typically lands around May 21, 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 Jun 11.
When is the first frost in Butte-Silver Bow?
The first hard freeze (28°F) in Butte-Silver Bow typically arrives around Sep 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 3, so the watching starts about Aug 18 — about 119 days after the spring freeze cleared.
How long is the growing season in Butte-Silver Bow?
Measured between 28°F hard freezes, Butte-Silver Bow sees about 119 frost-free days — roughly May 21 through Sep 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 11 to Sep 3, about 84 days.
Is the soil safe to grow vegetables in Butte-Silver Bow?
The federal record around Butte-Silver Bow runs heavier than most — 263 documented sites, mostly Underground Storage Tanks entries (136), the nearest Underground Storage Tanks record about 0.5 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do gardeners stretch the season in Butte-Silver Bow?
With about 119 frost-free days between hard freezes, Butte-Silver Bow 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 147 to 175 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 21 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Butte-Silver Bow's scale — its 4a band and its 119-day season. Your yard writes its own version of Butte-Silver Bow'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 Butte-Silver Bow’s own scale
6 of the readings below were taken at Butte-Silver Bow's own scale — its own ~119-day season between 28°F freezes, the 458,088 acres it covers and 263 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Butte-Silver Bow's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Butte-Silver Bow's own 28°F hard-freeze dates, about May 21 and Sep 17 and the ~119-day span between themNOAA 1991–2020 Climate Normals
- 263 documented contamination sites on the federal record near Butte-Silver Bow, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- Butte-Silver Bow's boundary and the 458,088 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~119-day seasonGrowable Ground crop-matching engine
- The ecoregion at Butte-Silver Bow's own centroid, the Middle RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Butte-Silver Bow's 458,088 acres read through its county's SSURGO summaryfrom Silver Bow County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Silver Bow 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 Silver Bow County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Butte-Silver Bow's 458,088 acreswhy one lot differs from the next →
- Which side of Butte-Silver Bow you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 458,088 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 Butte-Silver Bow-wide figureread your own land →
More in Montana
Wider growing context
What grows across MontanaButte-Silver Bow sits outside our named growing regions, so Montana as a whole is its closest context here.
Nearby growing guides