Willmar, Minnesota, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include cabbage, cranberry, turkish rocket, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Willmar, 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 Willmar 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 Willmar — soil, climate, flood, and parcel records. How we handle your address.
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Willmar — the short answer
Willmar, Minnesota: USDA zone 4b, about 179 days between hard freezes, across 9K 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 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~179
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 9K 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 Willmar's average, not your lot's — a low corner or a tree line moves it. Against Willmar's 179-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Willmar
Each reading below is measured for Willmar itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWillmar runs about 179 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
MeasuredWillmar 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 Willmar is in
Willmar sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Willmar's own centroid rather than borrowed from Kandiyohi County.
What Grows in Willmar
Every plant below cleared Willmar's own zone 4b and its 179-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Willmar?
Almost never — the real question is what to plant next. 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 16 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Willmar
Closest first, within ~10 miles of Willmar. Listing isn't leaking, and distance isn't exposure.
- JENNIE-O FOODS INCBrownfields · 150 ft
- JENNIE-O FOODS INCToxics Release Inventory · 150 ft
- Bills StandardUnderground Storage Tanks · 600 ft
- PERKINS LUMBER CO INCBrownfields · 700 ft
- WILLMAR MUNICIPAL UTILITIESBrownfields · 750 ft
- CATCO PARTS& SERVICE INCORPORATEDBrownfields · 900 ft
- ED'S SERVICE CENTERBrownfields · 1000 ft
- Holiday Stationstore #18Underground Storage Tanks · 1200 ft
- WILLMAR MUNICIPAL UTILITIES COMMISSIONToxics Release Inventory · 1500 ft
- Central Lakes Cooperative - WillmarUnderground Storage Tanks · 1600 ft
- WILLMAR MUNICIPAL UTILITIES - POWER PLANTToxics Release Inventory · 1600 ft
- WILLMAR MUNICIPAL UTILITIES - POWER PLANTBrownfields · 1600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Willmar'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 Willmar.
Total Sites
339
within ~10 miles of Willmar
Risk Level
Elevated
Highest-severity
13 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Willmar
Severity Distribution
within ~10 miles of Willmar
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Willmar, two things run higher than the national average within ~10 miles of Willmar — CAFO (7 sites) and Brownfields (167 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 Willmar
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 Willmar average
Your land is one point inside Willmar
Everything above resolves to Willmar as a whole — one PHZM band and one 28°F frost record, read across 9K 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 Willmar Average
Willmar Average
- ●USDA Zones 4b, averaged across Willmar
- ●One soil character for all of Willmar
- ●Frost dates read at Willmar's scale: Apr 20 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Willmar's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Willmar
Pull a site-specific report for your exact address in Willmar, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Willmar averages can't show:
We read public map data around Willmar — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Willmar average
How we know this about Willmar
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 Willmar’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 Willmar
When does frost risk typically end in Willmar?
The last hard freeze (28°F) in Willmar 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 Willmar?
The first hard freeze (28°F) in Willmar typically arrives around Oct 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 2, so the watching starts about Sep 16 — about 179 days after the spring freeze cleared.
How long is the growing season in Willmar?
Measured between 28°F hard freezes, Willmar sees about 179 frost-free days — roughly Apr 20 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 2, about 144 days.
Is the soil safe to grow vegetables in Willmar?
The federal record around Willmar is a meaningful one — 339 documented sites, mostly Brownfields entries (167), the nearest Brownfields record under a tenth of a mile 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 Willmar?
From about Sep 16 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Willmar's scale — its 4b band and its 179-day season. Your yard writes its own version of Willmar'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 Willmar’s own scale
6 of the readings below were taken at Willmar's own scale — its own ~179-day season between 28°F freezes, the 9,107 acres it covers and 339 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Willmar's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Willmar's own 28°F hard-freeze dates, about Apr 20 and Oct 16 and the ~179-day span between themNOAA 1991–2020 Climate Normals
- 339 documented contamination sites on the federal record near Willmar, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Willmar's boundary and the 9,107 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~179-day seasonGrowable Ground crop-matching engine
- The ecoregion at Willmar's own centroid, the Western Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Willmar's 9,107 acres read through its county's SSURGO summaryfrom Kandiyohi County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kandiyohi 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 Kandiyohi County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Willmar's 9,107 acreswhy one lot differs from the next →
- Which side of Willmar you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 9,107 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Willmar-wide figureread your own land →
More in Minnesota
Wider growing context
What grows across MinnesotaWillmar sits outside our named growing regions, so Minnesota as a whole is its closest context here.