Iron Junction, Minnesota, sits in USDA hardiness zone 4a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Crops well matched to these conditions include cabbage, cranberry, cilantro, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Iron Junction, 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 Iron Junction 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 Iron Junction — soil, climate, flood, and parcel records. How we handle your address.
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Iron Junction — the short answer
Iron Junction, Minnesota: USDA zone 4a, about 146 days between hard freezes, across 520 acres of city.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~146
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 520 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 Iron Junction's average, not your lot's — a low corner or a tree line moves it. Against Iron Junction's 146-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Iron Junction
Each reading below is measured for Iron Junction itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredIron Junction runs about 146 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
MeasuredIron Junction 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 Iron Junction is in
Iron Junction sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Iron Junction's own centroid rather than borrowed from St. Louis County.
What Grows in Iron Junction
Every plant below cleared Iron Junction's own zone 4a and its 146-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Iron Junction?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 2 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What's on the federal record near Iron Junction
Closest first, within ~10 miles of Iron Junction. Listing isn't leaking, and distance isn't exposure.
- EVELETH POLE YARDBrownfields · 1.0 mi
- CROSSROADS GAS & CONVENIENCEBrownfields · 1.2 mi
- Crossroads Convenience & GasUnderground Storage Tanks · 1.2 mi
- HOLMES RECYCLING SERVICES INC - IRON FACILITYBrownfields · 1.3 mi
- Holmes Recycling Services Inc - IronUnderground Storage Tanks · 1.3 mi
- ELLEFSON OFF HIGHWAY INCBrownfields · 1.4 mi
- NORTHERN NATURAL GAS - IRON JUNCTION VALVE SITEBrownfields · 2.0 mi
- DMIR RAILWAY - KEENAN YARDBrownfields · 2.1 mi
- Iron Juction YardUnderground Storage Tanks · 2.3 mi
- Keenan YardUnderground Storage Tanks · 2.3 mi
- TONY BERNARD FIELD TBWWToxics Release Inventory · 2.3 mi
- A 1 OIL SERVICES INCBrownfields · 3.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Iron Junction'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 Iron Junction.
Total Sites
318
within ~10 miles of Iron Junction
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Iron Junction
Severity Distribution
within ~10 miles of Iron Junction
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Iron Junction, Brownfields runs higher than the national average — 186 sites within ~10 miles of Iron Junction. That's not a problem with your land — it's information about it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Iron Junction
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 Iron Junction average
Your land is one point inside Iron Junction
Everything above resolves to Iron Junction as a whole — one PHZM band and one 28°F frost record, read across 520 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 Iron Junction Average
Iron Junction Average
- ●USDA Zones 4a, averaged across Iron Junction
- ●One soil character for all of Iron Junction
- ●Frost dates read at Iron Junction's scale: May 9 to Oct 2
YOUR Parcel
- ✓Your exact zone, not Iron Junction's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Iron Junction
Pull a site-specific report for your exact address in Iron Junction, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Iron Junction averages can't show:
We read public map data around Iron Junction — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Iron Junction average
How we know this about Iron Junction
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 Iron Junction’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 Iron Junction
When does frost risk typically end in Iron Junction?
The last hard freeze (28°F) in Iron Junction typically lands around May 9, 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 30.
When is the first frost in Iron Junction?
The first hard freeze (28°F) in Iron Junction typically arrives around Oct 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 18, so the watching starts about Sep 2 — about 146 days after the spring freeze cleared.
How long is the growing season in Iron Junction?
Measured between 28°F hard freezes, Iron Junction sees about 146 frost-free days — roughly May 9 through Oct 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 30 to Sep 18, about 111 days.
Is the soil safe to grow vegetables in Iron Junction?
The federal record around Iron Junction is a meaningful one — 318 documented sites, mostly Brownfields entries (186), the nearest Brownfields record about 1.0 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 Iron Junction?
With about 146 frost-free days between hard freezes, Iron Junction 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 174 to 202 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 9 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Iron Junction's scale — its 4a band and its 146-day season. Your yard writes its own version of Iron Junction'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 Iron Junction’s own scale
6 of the readings below were taken at Iron Junction's own scale — its own ~146-day season between 28°F freezes, the 520 acres it covers and 318 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Iron Junction's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Iron Junction's own 28°F hard-freeze dates, about May 9 and Oct 2 and the ~146-day span between themNOAA 1991–2020 Climate Normals
- 318 documented contamination sites on the federal record near Iron Junction, the closest Brownfields record about 1.0 miles out from the town centreFederal environmental registers
- Iron Junction's boundary and the 520 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~146-day seasonGrowable Ground crop-matching engine
- The ecoregion at Iron Junction's own centroid, the Northern Lakes and ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Iron Junction's 520 acres read through its county's SSURGO summaryfrom St. Louis County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom St. Louis County
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom St. Louis County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Iron Junction's 520 acreswhy one lot differs from the next →
- Which side of Iron Junction you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 520 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 1.0 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 Iron Junction-wide figureread your own land →
More in Minnesota
Wider growing context
What grows across MinnesotaIron Junction sits outside our named growing regions, so Minnesota as a whole is its closest context here.
Nearby growing guides