Blue Earth County, in Minnesota, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, cranberry, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Blue Earth County holds more than one microclimate.
Soils and elevations shift across Blue Earth County, so your frost dates and drainage aren't the county average. 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 Blue Earth County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Blue Earth County — the short answer
Blue Earth County, Minnesota: USDA zone 5a, about 184 days between hard freezes, across 479K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~184
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 479K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Blue Earth County's average, not your lot's — a low corner or a tree line moves it. Against Blue Earth County's 184-day season, see what your own ground reads.
Heat in Blue Earth County
Across a year, Blue Earth County accumulates about 2,467 growing degree days above 50°F, about 202 more than the middle Minnesota county — ahead of 79 of Minnesota’s 87 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Blue Earth County
Across Blue Earth County, the ground is predominantly Mollisols, where Marna, Beauford, and Minnetonka are the most extensive named soil series. The soil is generally poorly drained with a silty clay loam surface. Topsoil pH runs about 6.2–6.8, slightly acidic. Rainfall drains through hydrologic group C/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
29%
Hydric soils
58%
Soil still varies lot by lot — soil types explained.
How the ground varies across Blue Earth County
The USDA soil survey maps 44% of Blue Earth County as poorly drained — but another 53% drains differently: 14% somewhat poorly drained, 13% moderately well drained.
Marna is the most extensive named soil at 8% of mapped acres, then Beauford (7%) and Minnetonka (6%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Blue Earth County
Each reading below is measured for Blue Earth County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Blue Earth County are poorly drained, in hydrologic group C/D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Blue Earth County runs about pH 6.2–6.8, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredBlue Earth County runs about 184 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
MeasuredBlue Earth County 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 Blue Earth County is in
Blue Earth County spans 2 EPA Level III ecoregions — Western Corn Belt Plains (93%) and North Central Hardwood Forests (7%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Blue Earth County
We scored all 1,086 plants against Blue Earth County's own USDA zone 5a and its own 184-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Minnesota profile.
Is it too late to plant in Blue Earth County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (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. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Blue Earth County
- Japanese beetle1 documented records
- monarch butterfly133 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Blue Earth County
USGS estimates 280,329 lb of Glyphosate on Blue Earth County farmland in 2019, its largest by weight, ahead of Acetochlor (153,554 lb) and Metolachlor & Metolachlor-s (102,708 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Blue Earth County — and how to grow with it.
We checked the federal record across Blue Earth County — 1,111 documented sites across 7 of the 9 source types we track.
The most significant on record: 1 Superfund site. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Blue Earth County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Blue Earth County
Closest first, across Blue Earth County. Listing isn't leaking, and distance isn't exposure.
- Holiday Stationstore #11Underground Storage Tanks · 650 ft
- K Mart #3510Underground Storage Tanks · 650 ft
- Kwik Trip 449Underground Storage Tanks · 650 ft
- Mankato Ford IncUnderground Storage Tanks · 650 ft
- TOM RAHN NURSERY FINISHCAFO · 0.9 mi
- MULTI-SITE - KEVIN & LARRY RACAFO · 1.0 mi
- 516891Nitrate · 1.8 mi
- 463613Nitrate · 1.9 mi
- Knewtson AcresUnderground Storage Tanks · 1.9 mi
- MUNDT S AUTOBrownfields · 2.0 mi
- 106N27W09AADDCB01 GoodThunder 0000409640Nitrate · 2.1 mi
- BLUE EARTH COUNTY HIGHWAY DEPT - GOOD THUNDERBrownfields · 2.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Blue Earth County'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 Blue Earth County.
Sources Checked
across Blue Earth County
Severity Distribution
across Blue Earth County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Blue Earth County, two things run higher than the national average across Blue Earth County — CAFO (43 sites) and Nitrate (438 sites). That's not a problem with your land — it's information about 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 Blue Earth County
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 Blue Earth County average
Your land is one point inside Blue Earth County
Everything above resolves to Blue Earth County as a whole — one PHZM band and one county frost record, read across 479K 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 county 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 county average.
Your Lot vs the Blue Earth County Average
Blue Earth County Average
- ●USDA Zones 5a, averaged across Blue Earth County
- ●One soil character for all of Blue Earth County
- ●Frost dates read at Blue Earth County's scale: Apr 17 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Blue Earth County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Blue Earth County
Pull a site-specific report for your exact address in Blue Earth County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Blue Earth County averages can't show:
We read public map data around Blue Earth County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Blue Earth County average
How we know this about Blue Earth County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Blue Earth County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Blue Earth County
When does frost risk typically end in Blue Earth County?
The last hard freeze (28°F) in Blue Earth County typically lands around Apr 17, 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 8.
How long is the growing season in Blue Earth County?
Measured between 28°F hard freezes, Blue Earth County sees about 184 frost-free days — roughly Apr 17 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 4, about 149 days.
Is the soil safe to grow vegetables in Blue Earth County?
The federal record around Blue Earth County is a meaningful one — 1,111 documented sites, mostly Nitrate entries (438), the nearest Underground Storage Tanks 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.
Everything above is measured at Blue Earth County's scale — its 5a band and its 184-day season. Your yard writes its own version of Blue Earth County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Minnesota's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Blue Earth County’s own scale
9 of the readings below were taken at Blue Earth County's own scale — its own ~184-day span between 28°F freezes, the 3 most extensive soil series mapped here and 1,111 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Blue Earth County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Blue Earth County's own 28°F hard-freeze dates and its ~184-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Blue Earth CountyUSDA NRCS SSURGO
- 1,111 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.1 miles outFederal environmental registers
- Blue Earth County's boundary and the 478,615 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~184-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Blue Earth County spans, Western Corn Belt Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Blue Earth County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Blue Earth County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
What this page can’t tell you
- How the season shifts across Blue Earth County — the ~184 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Blue Earth County's 478,615 acreswhy one lot differs from the next →
- Which of those 1,111 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Blue Earth Countyread your own land →