Winneshiek County, in Iowa, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cabbage, cranberry, turkish rocket, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Winneshiek County lies within the Driftless Area — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Winneshiek County holds more than one microclimate.
Soils and elevations shift across Winneshiek 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 Winneshiek County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Winneshiek County — the short answer
Winneshiek County, Iowa: USDA zone 4b, about 188 days between hard freezes, across 442K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 16
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~188
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 442K 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 Winneshiek County's average, not your lot's — a low corner or a tree line moves it. Against Winneshiek County's 188-day season, see what your own ground reads.
Heat in Winneshiek County
Across a year, Winneshiek County accumulates about 2,396 growing degree days above 50°F, about 348 fewer than the middle Iowa county — ahead of 3 of Iowa’s 99 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 Winneshiek County
Across Winneshiek County, the ground is predominantly Alfisols, where Fayette, Downs, and Kasson are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.2–6.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
28%
Hydric soils
6%
Soil still varies lot by lot — soil types explained.
How the ground varies across Winneshiek County
The USDA soil survey maps 76% of Winneshiek County as well drained — but another 24% drains differently: 8% moderately well drained, 7% somewhat poorly drained.
Fayette is the most extensive named soil at 26% of mapped acres, then Downs (20%) and Kasson (4%).
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 Winneshiek County
Each reading below is measured for Winneshiek 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 Winneshiek 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 Winneshiek County runs about pH 6.2–6.5, 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
MeasuredWinneshiek County runs about 188 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
MeasuredWinneshiek County 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 Winneshiek County is in
Winneshiek County spans 2 EPA Level III ecoregions — Driftless Area (78%) and Western Corn Belt Plains (22%). 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 Winneshiek County
We scored all 1,086 plants against Winneshiek County's own USDA zone 4b and its own 188-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 Iowa profile.
Is it too late to plant in Winneshiek County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 21 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
Documented around Winneshiek County
- Japanese beetle4 documented records
- monarch butterfly1,656 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Winneshiek County
USGS estimates 215,075 lb of Glyphosate on Winneshiek County farmland in 2019, its largest by weight, ahead of Acetochlor (127,126 lb) and Atrazine (79,128 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 Winneshiek County — and how to grow with it.
We checked the federal record across Winneshiek County — 199 documented sites across 6 of the 9 source types we track.
The most significant on record: 8 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Winneshiek 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 Winneshiek County
Closest first, across Winneshiek County. Listing isn't leaking, and distance isn't exposure.
- IOWA DEPARTMENT OF TRANSPORTATIONBrownfields · 1.8 mi
- WINDRIDGE IMPLEMENTS L.L.C.Brownfields · 2.2 mi
- WINDRIDGE IMPLEMENTUnderground Storage Tanks · 2.3 mi
- HOLLAND BROS CONSTRUCTION CO INCUnderground Storage Tanks · 2.3 mi
- JUVE INCUnderground Storage Tanks · 2.3 mi
- NEW CONCEPTS PRE-MIXUnderground Storage Tanks · 2.3 mi
- DECORAH MOBILE GLASS INCUnderground Storage Tanks · 2.3 mi
- J B HOLLAND CONSTRUCTIONBrownfields · 2.3 mi
- DAVES MACHINEBrownfields · 2.5 mi
- FORMER NORTHEAST FARM SERVICEUnderground Storage Tanks · 2.5 mi
- AASE HAUGEN HOMES INCUnderground Storage Tanks · 2.6 mi
- DECORAH OPERATIONS ACUMENT GLOBAL TECHNOLOGIES CAMCAR LLCToxics Release Inventory · 2.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Winneshiek 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 Winneshiek County.
Total Sites
199
across Winneshiek County
Risk Level
Moderate
Highest-severity
8 Toxics Release Inventory facilities
Sources Checked
across Winneshiek County
Severity Distribution
across Winneshiek 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 Winneshiek 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 Winneshiek County average
Your land is one point inside Winneshiek County
Everything above resolves to Winneshiek County as a whole — one PHZM band and one county frost record, read across 442K 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 Winneshiek County Average
Winneshiek County Average
- ●USDA Zones 4b, averaged across Winneshiek County
- ●One soil character for all of Winneshiek County
- ●Frost dates read at Winneshiek County's scale: Apr 16 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Winneshiek County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Winneshiek County
Pull a site-specific report for your exact address in Winneshiek County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Winneshiek County averages can't show:
We read public map data around Winneshiek County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Winneshiek County average
How we know this about Winneshiek 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 Winneshiek County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Winneshiek County
When does frost risk typically end in Winneshiek County?
The last hard freeze (28°F) in Winneshiek County typically lands around Apr 16, 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 7.
How long is the growing season in Winneshiek County?
Measured between 28°F hard freezes, Winneshiek County sees about 188 frost-free days — roughly Apr 16 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 7 to Oct 7, about 153 days.
Is the soil safe to grow vegetables in Winneshiek County?
The federal record around Winneshiek County shows 199 documented sites, mostly Underground Storage Tanks entries (122), the nearest Brownfields record about 1.8 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 Winneshiek County's scale — its 4b band and its 188-day season. Your yard writes its own version of Winneshiek 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 Iowa's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Winneshiek County’s own scale
9 of the readings below were taken at Winneshiek County's own scale — its own ~188-day span between 28°F freezes, the 3 most extensive soil series mapped here and 199 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Winneshiek County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Winneshiek County's own 28°F hard-freeze dates and its ~188-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Winneshiek CountyUSDA NRCS SSURGO
- 199 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 1.8 miles outFederal environmental registers
- Winneshiek County's boundary and the 441,500 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~188-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Winneshiek County spans, Driftless Area the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Winneshiek County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Winneshiek County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
What this page can’t tell you
- How the season shifts across Winneshiek County — the ~188 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 Winneshiek County's 441,500 acreswhy one lot differs from the next →
- Which of those 199 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 Winneshiek Countyread your own land →