The Silos, Montana, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
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 The Silos, 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 The Silos 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 The Silos — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
The Silos — the short answer
The Silos, 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 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 10
- 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 The Silos's average, not your lot's — a low corner or a tree line moves it. Against The Silos's 164-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in The Silos
Each reading below is measured for The Silos itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredThe Silos 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
MeasuredThe Silos 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 The Silos is in
The Silos sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at The Silos's own centroid rather than borrowed from Broadwater County.
What Grows in The Silos
Every plant below cleared The Silos'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 The Silos?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 10 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near The Silos
Closest first, within ~10 miles of The Silos. Listing isn't leaking, and distance isn't exposure.
- White Gulch MineMining · 3.4 mi
- 7N1E23ACBA01Nitrate · 3.4 mi
- Kelly MineMining · 3.9 mi
- Valley View MineMining · 4.0 mi
- 08N02E32DB 02Nitrate · 4.1 mi
- 08N02E29DC 02Nitrate · 4.2 mi
- MidasMining · 4.7 mi
- Little BonanzaMining · 4.7 mi
- Iron Age GroupMining · 4.8 mi
- Stolen Sweets MineMining · 4.8 mi
- North Star MineMining · 4.8 mi
- 7N1E28CCBANitrate · 5.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from The Silos'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 The Silos.
Total Sites
204
within ~10 miles of The Silos
Risk Level
High
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of The Silos
Severity Distribution
within ~10 miles of The Silos
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around The Silos, two things run higher than the national average within ~10 miles of The Silos — Mining (105 sites) and Nitrate (54 sites). That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in The Silos
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 Silos average
Your land is one point inside The Silos
Everything above resolves to The Silos 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 The Silos Average
The Silos Average
- ●USDA Zones 4b, averaged across The Silos
- ●One soil character for all of The Silos
- ●Frost dates read at The Silos's scale: Apr 29 to Oct 10
YOUR Parcel
- ✓Your exact zone, not The Silos's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in The Silos
Pull a site-specific report for your exact address in The Silos, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Silos averages can't show:
We read public map data around The Silos — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Silos average
How we know this about The Silos
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 The Silos’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 The Silos
When does frost risk typically end in The Silos?
The last hard freeze (28°F) in The Silos 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 The Silos?
The first hard freeze (28°F) in The Silos typically arrives around Oct 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 26, so the watching starts about Sep 10 — about 164 days after the spring freeze cleared.
How long is the growing season in The Silos?
Measured between 28°F hard freezes, The Silos sees about 164 frost-free days — roughly Apr 29 through Oct 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 20 to Sep 26, about 129 days.
Is the soil safe to grow vegetables in The Silos?
The federal record around The Silos runs heavier than most — 204 documented sites, mostly Mining entries (105), the nearest Mining record about 3.4 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 I protect my plants from frost in The Silos?
From about Sep 10 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at The Silos's scale — its 4b band and its 164-day season. Your yard writes its own version of The Silos'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 The Silos’s own scale
6 of the readings below were taken at The Silos's own scale — its own ~164-day season between 28°F freezes, the 3,283 acres it covers and 204 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- The Silos's own USDA hardiness band, zones 4bUSDA PHZM 2023
- The Silos's own 28°F hard-freeze dates, about Apr 29 and Oct 10 and the ~164-day span between themNOAA 1991–2020 Climate Normals
- 204 documented contamination sites on the federal record near The Silos, the closest Mining record about 3.4 miles out from the town centreFederal environmental registers
- The Silos's boundary and the 3,283 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 The Silos's own centroid, the Middle RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so The Silos's 3,283 acres read through its county's SSURGO summaryfrom Broadwater County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Broadwater 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 Broadwater County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among The Silos's 3,283 acreswhy one lot differs from the next →
- Which side of The Silos you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,283 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 3.4 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 The Silos-wide figureread your own land →
More in Montana
Wider growing context
What grows across MontanaThe Silos sits outside our named growing regions, so Montana as a whole is its closest context here.
Nearby growing guides