Harlem, Montana, sits in USDA hardiness zone 3b — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, cranberry, turkish rocket, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Harlem, 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 Harlem 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 Harlem — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Harlem — the short answer
Harlem, Montana: USDA zone 3b, about 150 days between hard freezes, across 268 acres of city.
- USDA zone
- 3b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 4
- 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
- ~150
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 268 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 3b is Harlem's average, not your lot's — a low corner or a tree line moves it. Against Harlem's 150-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Harlem
Each reading below is measured for Harlem itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHarlem runs about 150 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
MeasuredHarlem sits in USDA hardiness zone 3b.
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 Harlem is in
Harlem sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Harlem's own centroid rather than borrowed from Blaine County.
What Grows in Harlem
Every plant below cleared Harlem's own zone 3b and its 150-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Harlem?
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 6; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 4 (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. 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 Harlem
Closest first, within ~10 miles of Harlem. Listing isn't leaking, and distance isn't exposure.
- HARLEM AIRPORTUnderground Storage Tanks · 200 ft
- PHS INDIAN HOSPITALUnderground Storage Tanks · 200 ft
- BN HARLEM SECTION TOOL HOUSEUnderground Storage Tanks · 200 ft
- NORTH HARLEM COLONYUnderground Storage Tanks · 200 ft
- BAKERS SERVICE CENTER INCUnderground Storage Tanks · 500 ft
- FRED O DOLVENUnderground Storage Tanks · 750 ft
- EQUITY COOP ASSOCIATION CENTRAL AVE WUnderground Storage Tanks · 800 ft
- HARLEM SHOPUnderground Storage Tanks · 1300 ft
- FORMER GAS STATION HARLEMUnderground Storage Tanks · 1400 ft
- E Z MARTUnderground Storage Tanks · 2000 ft
- BUREAU OF INDIAN AFFAIRS FACILITYBrownfields · 3.7 mi
- FORT BELKNAP KWIKSTOPUnderground Storage Tanks · 3.7 mi
2 more sites are on the record inside the same radius. See them on the map
Measured from Harlem'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 Harlem.
Severity Distribution
within ~10 miles of Harlem
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Harlem
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 Harlem average
Your land is one point inside Harlem
Everything above resolves to Harlem as a whole — one PHZM band and one 28°F frost record, read across 268 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 city 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 Harlem Average
Harlem Average
- ●USDA Zones 3b, averaged across Harlem
- ●One soil character for all of Harlem
- ●Frost dates read at Harlem's scale: May 4 to Oct 1
YOUR Parcel
- ✓Your exact zone, not Harlem's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Harlem
Pull a site-specific report for your exact address in Harlem, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Harlem averages can't show:
We read public map data around Harlem — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Harlem average
How we know this about Harlem
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Harlem’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 city grain anywhere on this page — there is no city-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 Harlem
When does frost risk typically end in Harlem?
The last hard freeze (28°F) in Harlem typically lands around May 4, 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 25.
When is the first frost in Harlem?
The first hard freeze (28°F) in Harlem 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 150 days after the spring freeze cleared.
How long is the growing season in Harlem?
Measured between 28°F hard freezes, Harlem sees about 150 frost-free days — roughly May 4 through Oct 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 25 to Sep 17, about 115 days.
Is the soil safe to grow vegetables in Harlem?
The federal record around Harlem is light — 15 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (12), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Harlem?
From about Sep 1 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 1 (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 1. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Harlem's scale — its 3b band and its 150-day season. Your yard writes its own version of Harlem'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 Harlem’s own scale
6 of the readings below were taken at Harlem's own scale — its own ~150-day season between 28°F freezes, the 268 acres it covers and 15 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Harlem's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Harlem's own 28°F hard-freeze dates, about May 4 and Oct 1 and the ~150-day span between themNOAA 1991–2020 Climate Normals
- 15 documented contamination sites on the federal record near Harlem, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Harlem's boundary and the 268 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~150-day seasonGrowable Ground crop-matching engine
- The ecoregion at Harlem's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Harlem's 268 acres read through its county's SSURGO summaryfrom Blaine County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Blaine 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 Blaine County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Harlem's 268 acreswhy one lot differs from the next →
- Which side of Harlem you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 268 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Harlem-wide figureread your own land →
More in Montana
Growing region
Nearby growing guides