Cook County, in Minnesota, sits in USDA hardiness zone 4b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — cabbage, cranberry, turkish rocket, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Cook County holds more than one microclimate.
Soils and elevations shift across Cook 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 Cook County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Cook County — the short answer
Cook County, Minnesota: USDA zone 4b, about 181 days between hard freezes, across 930K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 930K 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 4b is Cook County's average, not your lot's — a low corner or a tree line moves it. Against Cook County's 181-day season, see what your own ground reads.
Heat in Cook County
Across a year, Cook County accumulates about 1,062 growing degree days above 50°F, about 1,203 fewer than the middle Minnesota county — no other Minnesota county banks fewer. 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 Cook County
Across Cook County, the ground is predominantly Inceptisols, where Eveleth, Conic, and Rifle are the most extensive named soil series. The soil is generally well drained with a stony loam surface. Topsoil pH runs about 4.9–5.5, strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Inceptisols
Drainage
Well drained
Hydric soils
32%
Soil still varies lot by lot — soil types explained.
How the ground varies across Cook County
The USDA soil survey maps 49% of Cook County as well drained — but another 37% drains differently: 16% very poorly drained, 13% moderately well drained.
Eveleth is the most extensive named soil at 18% of mapped acres, then Conic (13%) and Rifle (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 Cook County
Each reading below is measured for Cook 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 Cook County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Cook County runs about pH 4.9–5.5, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Wet ground
MeasuredAbout 32% of Cook County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredCook County 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
The kind of country Cook County is in
Cook County sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. One consistent ecological setting across the whole county.
What Grows in Cook County
We scored all 1,086 plants against Cook County's own USDA zone 4b and its own 181-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 Cook County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — 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 Cook County
- monarch butterfly17 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Cook County
USGS estimates 34 lb of Glyphosate on Cook County farmland in 2019, its largest by weight, ahead of 2,4-d (21 lb) and Metolachlor & Metolachlor-s (11 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 Cook County — and how to grow with it.
We checked the federal record across Cook County — 145 documented sites across 5 of the 9 source types we track.
The most significant on record: 1 Toxics Release Inventory facility. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Cook County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Cook County
Closest first, across Cook County. Listing isn't leaking, and distance isn't exposure.
- Cook County Recycling CenterUnderground Storage Tanks · 1100 ft
- COOK COUNTY NORTH SHORE HOSPITALBrownfields · 1200 ft
- Uscg Station North SuperiorUnderground Storage Tanks · 0.6 mi
- NORTH HOUSE FOLK SCHOOLBrownfields · 0.7 mi
- Qwest Communications/Century LinkUnderground Storage Tanks · 0.7 mi
- School Bus GarageUnderground Storage Tanks · 0.7 mi
- Main Street GiftsUnderground Storage Tanks · 0.7 mi
- Grand Marais Rec Area MarinaUnderground Storage Tanks · 0.7 mi
- NORTH SHORE PHARMACY LTDBrownfields · 0.7 mi
- Buck's HardwareUnderground Storage Tanks · 0.7 mi
- Former Schold & Lovaas Service StationUnderground Storage Tanks · 0.7 mi
- Mike's Holiday Stationstore #516Underground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Cook 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 Cook County.
Total Sites
145
across Cook County
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
across Cook County
Severity Distribution
across Cook County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Cook County, Nitrate runs higher than the national average — 46 sites across Cook County. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Cook 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 Cook County average
Your land is one point inside Cook County
Everything above resolves to Cook County as a whole — one PHZM band and one county frost record, read across 930K 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 Cook County Average
Cook County Average
- ●USDA Zones 4b, averaged across Cook County
- ●One soil character for all of Cook County
- ●Frost dates read at Cook County's scale: Apr 28 to Oct 26
YOUR Parcel
- ✓Your exact zone, not Cook County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Cook County
Pull a site-specific report for your exact address in Cook County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Cook County averages can't show:
We read public map data around Cook County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Cook County average
How we know this about Cook 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 Cook County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Cook County
When does frost risk typically end in Cook County?
The last hard freeze (28°F) in Cook County typically lands around Apr 28, 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 19.
How long is the growing season in Cook County?
Measured between 28°F hard freezes, Cook County sees about 181 frost-free days — roughly Apr 28 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Oct 12, about 146 days.
Is the soil safe to grow vegetables in Cook County?
The federal record around Cook County shows 145 documented sites, mostly Underground Storage Tanks entries (59), 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.
Everything above is measured at Cook County's scale — its 4b band and its 181-day season. Your yard writes its own version of Cook 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 Cook County’s own scale
9 of the readings below were taken at Cook County's own scale — its own ~181-day span between 28°F freezes, the 3 most extensive soil series mapped here and 145 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Cook County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Cook County's own 28°F hard-freeze dates and its ~181-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Cook CountyUSDA NRCS SSURGO
- 145 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.2 miles outFederal environmental registers
- Cook County's boundary and the 929,666 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~181-day seasonGrowable Ground crop-matching engine
- Cook County sitting wholly inside the Northern Lakes and ForestsUS EPA Level III Ecoregions
- Open occurrence records documented in Cook County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Cook 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 Cook County — the ~181 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 Cook County's 929,666 acreswhy one lot differs from the next →
- Which of those 145 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 Cook Countyread your own land →