Heidelberg, Minnesota, 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 Heidelberg, 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 Heidelberg 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 Heidelberg — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Heidelberg — the short answer
Heidelberg, Minnesota: USDA zone 4b, about 181 days between hard freezes, across 335 acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 335 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 Heidelberg's average, not your lot's — a low corner or a tree line moves it. Against Heidelberg's 181-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Heidelberg
Each reading below is measured for Heidelberg itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHeidelberg runs about 181 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
MeasuredHeidelberg 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 Heidelberg is in
Heidelberg sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Heidelberg's own centroid rather than borrowed from Le Sueur County.
What Grows in Heidelberg
Every plant below cleared Heidelberg's own zone 4b and its 181-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Heidelberg?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 18 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Heidelberg
Closest first, within ~10 miles of Heidelberg. Listing isn't leaking, and distance isn't exposure.
- STARS & STRIPES GARAGEBrownfields · 800 ft
- ANDERSON ENGINEERING OF NEW PRAGUE INCBrownfields · 2.7 mi
- 432895Nitrate · 3.1 mi
- ITC MIDWEST - NEW PRAGUEBrownfields · 3.2 mi
- CITY'S EDGE COLLISION & GLASS INC - NEW PRAGUEBrownfields · 3.3 mi
- BRAUN PUMP & CONTROLS INC - 3Brownfields · 3.3 mi
- MAYLON'S REPAIRBrownfields · 3.5 mi
- UNLIMITED MOTORSPORTSBrownfields · 3.6 mi
- WELCOME AUTOBrownfields · 3.7 mi
- New PraguePFAS · 3.7 mi
- Formerly Gas Station (russell Gontarek)Underground Storage Tanks · 3.7 mi
- Mahowald Motors IncUnderground Storage Tanks · 3.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Heidelberg'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 Heidelberg.
Total Sites
210
within ~10 miles of Heidelberg
Risk Level
Elevated
Highest-severity
8 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Heidelberg
Severity Distribution
within ~10 miles of Heidelberg
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Heidelberg, two things run higher than the national average within ~10 miles of Heidelberg — CAFO (4 sites) and Brownfields (116 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Heidelberg
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 Heidelberg average
Your land is one point inside Heidelberg
Everything above resolves to Heidelberg as a whole — one PHZM band and one 28°F frost record, read across 335 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 Heidelberg Average
Heidelberg Average
- ●USDA Zones 4b, averaged across Heidelberg
- ●One soil character for all of Heidelberg
- ●Frost dates read at Heidelberg's scale: Apr 20 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Heidelberg's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Heidelberg
Pull a site-specific report for your exact address in Heidelberg, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Heidelberg averages can't show:
We read public map data around Heidelberg — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Heidelberg average
How we know this about Heidelberg
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 Heidelberg’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 Heidelberg
When does frost risk typically end in Heidelberg?
The last hard freeze (28°F) in Heidelberg typically lands around Apr 20, 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 11.
When is the first frost in Heidelberg?
The first hard freeze (28°F) in Heidelberg typically arrives around Oct 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 4, so the watching starts about Sep 18 — about 181 days after the spring freeze cleared.
How long is the growing season in Heidelberg?
Measured between 28°F hard freezes, Heidelberg sees about 181 frost-free days — roughly Apr 20 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 4, about 146 days.
Is the soil safe to grow vegetables in Heidelberg?
The federal record around Heidelberg is a meaningful one — 210 documented sites, mostly Brownfields entries (116), the nearest Brownfields record about 0.1 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 I protect my plants from frost in Heidelberg?
From about Sep 18 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 18 (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 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Heidelberg's scale — its 4b band and its 181-day season. Your yard writes its own version of Heidelberg'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 Heidelberg’s own scale
6 of the readings below were taken at Heidelberg's own scale — its own ~181-day season between 28°F freezes, the 335 acres it covers and 210 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Heidelberg's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Heidelberg's own 28°F hard-freeze dates, about Apr 20 and Oct 18 and the ~181-day span between themNOAA 1991–2020 Climate Normals
- 210 documented contamination sites on the federal record near Heidelberg, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Heidelberg's boundary and the 335 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~181-day seasonGrowable Ground crop-matching engine
- The ecoregion at Heidelberg's own centroid, the North Central Hardwood ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Heidelberg's 335 acres read through its county's SSURGO summaryfrom Le Sueur County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Le Sueur 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 Le Sueur County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Heidelberg's 335 acreswhy one lot differs from the next →
- Which side of Heidelberg you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 335 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Heidelberg-wide figureread your own land →
More in Minnesota
Wider growing context
What grows across MinnesotaHeidelberg sits outside our named growing regions, so Minnesota as a whole is its closest context here.
Nearby growing guides