Heron Lake, Minnesota, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Heron Lake, 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 Heron Lake 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 Heron Lake — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Heron Lake — the short answer
Heron Lake, Minnesota: USDA zone 5a, about 177 days between hard freezes, across 795 acres of city.
- USDA zone
- 5a
- 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 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~177
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 795 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 5a is Heron Lake's average, not your lot's — a low corner or a tree line moves it. Against Heron Lake's 177-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Heron Lake
Each reading below is measured for Heron Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHeron Lake runs about 177 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
MeasuredHeron Lake sits in USDA hardiness zone 5a.
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 Heron Lake is in
Heron Lake sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Heron Lake's own centroid rather than borrowed from Jackson County.
What Grows in Heron Lake
Every plant below cleared Heron Lake's own zone 5a and its 177-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Heron Lake?
Usually not — gardeners here simply switch what goes in the ground as the season moves. 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 14 — 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 Heron Lake
Closest first, within ~10 miles of Heron Lake. Listing isn't leaking, and distance isn't exposure.
- Schaffer Mobil ServiceUnderground Storage Tanks · 900 ft
- C AND C EQUIPMENTBrownfields · 1200 ft
- 104N37W19DBD 01 Heron LakeNitrate · 1500 ft
- 104N37W19DDA 01 Jackson CityNitrate · 2100 ft
- P & J's Mini MartUnderground Storage Tanks · 0.6 mi
- HERON LAKE BIOENERGY, LLCToxics Release Inventory · 1.7 mi
- HERON LAKE BIOENERGY, LLCBrownfields · 1.7 mi
- BRIAN & MARK SOLETA FARMCAFO · 2.7 mi
- ITC MIDWEST HERON LAKEBrownfields · 2.8 mi
- 115276Nitrate · 3.1 mi
- JANSMA REPAIR SERVICEBrownfields · 3.9 mi
- SOLETA REPAIRBrownfields · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Heron Lake'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 Heron Lake.
Total Sites
74
within ~10 miles of Heron Lake
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Heron Lake
Severity Distribution
within ~10 miles of Heron Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Heron Lake, two things run higher than the national average within ~10 miles of Heron Lake — CAFO (6 sites) and Nitrate (26 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Heron Lake
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 Heron Lake average
Your land is one point inside Heron Lake
Everything above resolves to Heron Lake as a whole — one PHZM band and one 28°F frost record, read across 795 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 Heron Lake Average
Heron Lake Average
- ●USDA Zones 5a, averaged across Heron Lake
- ●One soil character for all of Heron Lake
- ●Frost dates read at Heron Lake's scale: Apr 20 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Heron Lake's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Heron Lake
Pull a site-specific report for your exact address in Heron Lake, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Heron Lake averages can't show:
We read public map data around Heron Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Heron Lake average
How we know this about Heron Lake
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 Heron Lake’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 Heron Lake
When does frost risk typically end in Heron Lake?
The last hard freeze (28°F) in Heron Lake 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 Heron Lake?
The first hard freeze (28°F) in Heron Lake typically arrives around Oct 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 30, so the watching starts about Sep 14 — about 177 days after the spring freeze cleared.
How long is the growing season in Heron Lake?
Measured between 28°F hard freezes, Heron Lake sees about 177 frost-free days — roughly Apr 20 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Sep 30, about 142 days.
Is the soil safe to grow vegetables in Heron Lake?
The federal record around Heron Lake shows 74 documented sites, mostly Underground Storage Tanks entries (31), the nearest Underground Storage Tanks record about 0.2 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Heron Lake?
From about Sep 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Heron Lake's scale — its 5a band and its 177-day season. Your yard writes its own version of Heron Lake'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 Heron Lake’s own scale
6 of the readings below were taken at Heron Lake's own scale — its own ~177-day season between 28°F freezes, the 795 acres it covers and 74 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Heron Lake's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Heron Lake's own 28°F hard-freeze dates, about Apr 20 and Oct 14 and the ~177-day span between themNOAA 1991–2020 Climate Normals
- 74 documented contamination sites on the federal record near Heron Lake, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Heron Lake's boundary and the 795 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~177-day seasonGrowable Ground crop-matching engine
- The ecoregion at Heron Lake'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 Heron Lake's 795 acres read through its county's SSURGO summaryfrom Jackson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jackson 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 Jackson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Heron Lake's 795 acreswhy one lot differs from the next →
- Which side of Heron Lake you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 795 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Heron Lake-wide figureread your own land →
More in Minnesota
Wider growing context
What grows across MinnesotaHeron Lake sits outside our named growing regions, so Minnesota as a whole is its closest context here.