Zortman, Montana, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, cranberry, cilantro, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Zortman, 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 Zortman 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 Zortman — soil, climate, flood, and parcel records. How we handle your address.
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Zortman — the short answer
Zortman, Montana: USDA zone 4b, about 147 days between hard freezes, across 3K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~147
- 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 Zortman's average, not your lot's — a low corner or a tree line moves it. Against Zortman's 147-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Zortman
Each reading below is measured for Zortman itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredZortman runs about 147 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
MeasuredZortman 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 Zortman is in
Zortman sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Zortman's own centroid, and it is not what its county reads: Phillips County is mostly Northwestern Glaciated Plains. The wider page above you is answering a different question about different ground.
What Grows in Zortman
Every plant below cleared Zortman's own zone 4b and its 147-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Zortman?
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 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 Oct 1 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
What's on the federal record near Zortman
Closest first, within ~10 miles of Zortman. Listing isn't leaking, and distance isn't exposure.
- Frank MineMining · 1700 ft
- Bailey GroupMining · 1700 ft
- Camp ProspectMining · 1700 ft
- PETE CLAUSEN & SONS INCUnderground Storage Tanks · 0.7 mi
- ZORTMAN LANDUSKY MINING COUnderground Storage Tanks · 0.7 mi
- Lucky MaudMining · 2.3 mi
- Antone PeakMining · 3.4 mi
- Jack DeuceMining · 4.6 mi
- ZORTMAN MINING INCBrownfields · 4.7 mi
- BUCKHORN STOREUnderground Storage Tanks · 5.1 mi
- ZORTMAN GARAGE & MOTELUnderground Storage Tanks · 5.1 mi
- ZORTMAN WORK CENTERUnderground Storage Tanks · 5.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Zortman'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 Zortman.
Total Sites
100
within ~10 miles of Zortman
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Zortman
Severity Distribution
within ~10 miles of Zortman
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Zortman, two things run higher than the national average within ~10 miles of Zortman — Nitrate (80 sites) and Mining (7 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Zortman
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 Zortman average
Your land is one point inside Zortman
Everything above resolves to Zortman 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 Zortman Average
Zortman Average
- ●USDA Zones 4b, averaged across Zortman
- ●One soil character for all of Zortman
- ●Frost dates read at Zortman's scale: May 7 to Oct 1
YOUR Parcel
- ✓Your exact zone, not Zortman's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Zortman
Pull a site-specific report for your exact address in Zortman, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Zortman averages can't show:
We read public map data around Zortman — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Zortman average
How we know this about Zortman
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 Zortman’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 Zortman
When does frost risk typically end in Zortman?
The last hard freeze (28°F) in Zortman 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 Zortman?
The first hard freeze (28°F) in Zortman typically arrives around Oct 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 17, so the watching starts about Sep 1 — about 147 days after the spring freeze cleared.
How long is the growing season in Zortman?
Measured between 28°F hard freezes, Zortman sees about 147 frost-free days — roughly May 7 through Oct 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 17, about 112 days.
Is the soil safe to grow vegetables in Zortman?
The federal record around Zortman is a meaningful one — 100 documented sites, mostly Nitrate entries (80), the nearest Mining record about 0.3 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 Zortman?
With about 147 frost-free days between hard freezes, Zortman 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 175 to 203 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 Zortman's scale — its 4b band and its 147-day season. Your yard writes its own version of Zortman'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 Zortman’s own scale
6 of the readings below were taken at Zortman's own scale — its own ~147-day season between 28°F freezes, the 2,530 acres it covers and 100 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Zortman's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Zortman's own 28°F hard-freeze dates, about May 7 and Oct 1 and the ~147-day span between themNOAA 1991–2020 Climate Normals
- 100 documented contamination sites on the federal record near Zortman, the closest Mining record about 0.3 miles out from the town centreFederal environmental registers
- Zortman's boundary and the 2,530 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~147-day seasonGrowable Ground crop-matching engine
- Zortman sits in the Middle 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 Zortman's 2,530 acres read through its county's SSURGO summaryfrom Phillips County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Phillips 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 Phillips County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Zortman's 2,530 acreswhy one lot differs from the next →
- Which side of Zortman you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,530 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.3 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 Zortman-wide figureread your own land →
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