Koochiching County, in Minnesota, sits in USDA hardiness zone 3b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cabbage, cranberry, epazote, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Koochiching County holds more than one microclimate.
Soils and elevations shift across Koochiching 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 Koochiching County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Koochiching County — the short answer
Koochiching County, Minnesota: USDA zone 3b, about 143 days between hard freezes, across 2.0M acres.
- USDA zone
- 3b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 9
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Sep 29
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~143
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 2.0M 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 3b is Koochiching County's average, not your lot's — a low corner or a tree line moves it. Against Koochiching County's 143-day season, see what your own ground reads.
Heat in Koochiching County
Across a year, Koochiching County accumulates about 1,526 growing degree days above 50°F, about 739 fewer than the middle Minnesota county — ahead of 3 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 Koochiching County
Across Koochiching County, the ground is predominantly Histosols, where Greenwood, Effie, and Cathro are the most extensive named soil series. The soil is generally very poorly drained with a loam surface. Topsoil pH runs about 5.8–6.3, moderately acidic. Rainfall drains through hydrologic group C/D soils.
Soil order
Histosols
Drainage
Very poorly drained
Prime farmland
4%
Hydric soils
76%
Soil still varies lot by lot — soil types explained.
How the ground varies across Koochiching County
The USDA soil survey maps 52% of Koochiching County as very poorly drained — but another 43% drains differently: 16% poorly drained, 14% somewhat poorly drained.
Greenwood is the most extensive named soil at 18% of mapped acres, then Effie (7%) and Cathro (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 Koochiching County
Each reading below is measured for Koochiching 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 Koochiching County are very 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 Koochiching County runs about pH 5.8–6.3, 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
MeasuredKoochiching County runs about 143 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
MeasuredKoochiching County sits in USDA hardiness zone 3b.
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 Koochiching County is in
Koochiching County spans 2 EPA Level III ecoregions — Northern Minnesota Wetlands (90%) and Northern Lakes and Forests (10%). 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 Koochiching County
We scored all 1,086 plants against Koochiching County's own USDA zone 3b and its own 143-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 Koochiching County?
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 Sep 29 — 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.
Documented around Koochiching County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Koochiching County
USGS estimates 8,803 lb of Glyphosate on Koochiching County farmland in 2019, its largest by weight, ahead of Acetochlor (1,923 lb) and 2,4-d (1,646 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 Koochiching County — and how to grow with it.
We checked the federal record across Koochiching County — 174 documented sites across 6 of the 9 source types we track.
The most significant on record: 1 Superfund site (none NPL-listed). 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 Koochiching 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 Koochiching County
Closest first, across Koochiching County. Listing isn't leaking, and distance isn't exposure.
- Bureau Of Indian AffairsUnderground Storage Tanks · 500 ft
- Erics PlaceUnderground Storage Tanks · 500 ft
- PAGE & HILL FOREST PRODUCTS INCToxics Release Inventory · 3.3 mi
- KOOCHICHING COUNTY HIGHWAY DEBrownfields · 3.8 mi
- Promersberger's CornerUnderground Storage Tanks · 3.8 mi
- Forestry Dist Headquarters (dnr)Underground Storage Tanks · 8.8 mi
- Roches AmocoUnderground Storage Tanks · 8.8 mi
- Big Falls AirportUnderground Storage Tanks · 8.8 mi
- County Highway Garage - Big FallsUnderground Storage Tanks · 8.8 mi
- 464052Nitrate · 10.5 mi
- 189460Nitrate · 11.4 mi
- STANS WOOD CHIPSBrownfields · 12.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Koochiching 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 Koochiching County.
Total Sites
174
across Koochiching County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Koochiching County
Severity Distribution
across Koochiching County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Koochiching 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 Koochiching County average
Your land is one point inside Koochiching County
Everything above resolves to Koochiching County as a whole — one PHZM band and one county frost record, read across 2.0M 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 Koochiching County Average
Koochiching County Average
- ●USDA Zones 3b, averaged across Koochiching County
- ●One soil character for all of Koochiching County
- ●Frost dates read at Koochiching County's scale: May 9 to Sep 29
YOUR Parcel
- ✓Your exact zone, not Koochiching County's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Koochiching County
Pull a site-specific report for your exact address in Koochiching County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Koochiching County averages can't show:
We read public map data around Koochiching County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Koochiching County average
How we know this about Koochiching 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 Koochiching County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Koochiching County
When does frost risk typically end in Koochiching County?
The last hard freeze (28°F) in Koochiching County 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.
How long is the growing season in Koochiching County?
Measured between 28°F hard freezes, Koochiching County sees about 143 frost-free days — roughly May 9 through Sep 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 30 to Sep 15, about 108 days.
Is the soil safe to grow vegetables in Koochiching County?
The federal record around Koochiching County is a meaningful one — 174 documented sites, mostly Underground Storage Tanks entries (91), the nearest Underground Storage Tanks 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 gardeners stretch the season in Koochiching County?
With about 143 frost-free days between hard freezes, Koochiching County 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 171 to 199 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 Koochiching County's scale — its 3b band and its 143-day season. Your yard writes its own version of Koochiching 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 Koochiching County’s own scale
9 of the readings below were taken at Koochiching County's own scale — its own ~143-day span between 28°F freezes, the 3 most extensive soil series mapped here and 174 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Koochiching County's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Koochiching County's own 28°F hard-freeze dates and its ~143-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Koochiching CountyUSDA NRCS SSURGO
- 174 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record under a tenth of a mile outFederal environmental registers
- Koochiching County's boundary and the 1,987,010 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~143-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Koochiching County spans, Northern Minnesota Wetlands the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Koochiching County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Koochiching 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 Koochiching County — the ~143 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 Koochiching County's 1,987,010 acreswhy one lot differs from the next →
- Which of those 174 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 Koochiching Countyread your own land →