Oconto County, in Wisconsin, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
A short list that earns its place here — cabbage, cranberry, lavender, 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
Oconto County holds more than one microclimate.
Soils and elevations shift across Oconto 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 Oconto County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Oconto County — the short answer
Oconto County, Wisconsin: USDA zone 5a, about 164 days between hard freezes, across 638K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 2
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 13
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~164
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 638K 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 Oconto County's average, not your lot's — a low corner or a tree line moves it. Against Oconto County's 164-day season, see what your own ground reads.
Heat in Oconto County
Across a year, Oconto County accumulates about 1,983 growing degree days above 50°F, about 167 fewer than the middle Wisconsin county — ahead of 22 of Wisconsin’s 72 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 Oconto County
Across Oconto County, the ground is predominantly Spodosols, where Onaway, Menahga, and Padus are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 5.5–6.5, moderately acidic. Rainfall drains through hydrologic group A soils.
Soil order
Spodosols
Drainage
Well drained
Prime farmland
6%
Hydric soils
23%
Soil still varies lot by lot — soil types explained.
How the ground varies across Oconto County
The USDA soil survey maps 31% of Oconto County as well drained — but another 67% drains differently: 21% somewhat poorly drained, 14% very poorly drained.
Onaway is the most extensive named soil at 9% of mapped acres, then Menahga (7%) and Padus (7%).
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 Oconto County
Each reading below is measured for Oconto 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 Oconto County are well drained, in hydrologic group A — 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 Oconto County runs about pH 5.5–6.5, 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
Wet ground
MeasuredAbout 23% of Oconto 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
MeasuredOconto County runs about 164 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 Oconto County is in
Oconto County spans 2 EPA Level III ecoregions — North Central Hardwood Forests (56%) and Northern Lakes and Forests (44%). 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 Oconto County
We scored all 1,086 plants against Oconto County's own USDA zone 5a and its own 164-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 Wisconsin profile.
Is it too late to plant in Oconto 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 Apr 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 13 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Oconto County
- monarch butterfly3 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Oconto County
USGS estimates 34,408 lb of Glyphosate on Oconto County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (19,348 lb) and Acetochlor (13,797 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 Oconto County — and how to grow with it.
We checked the federal record across Oconto County — 535 documented sites across 7 of the 9 source types we track.
The most significant on record: 6 Superfund sites (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 Oconto 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 Oconto County
Closest first, across Oconto County. Listing isn't leaking, and distance isn't exposure.
- Kelly Lake Kwik StopUnderground Storage Tanks · 1.8 mi
- ED & LILS KELLY LAKE GROCERYUnderground Storage Tanks · 2.0 mi
- RITA L IMMELUnderground Storage Tanks · 2.3 mi
- EDWARD J STODOLAUnderground Storage Tanks · 2.6 mi
- LEE LAKE TAVERNUnderground Storage Tanks · 3.1 mi
- WEBERUnderground Storage Tanks · 3.7 mi
- CYNTHIA & ALLAN TALBOTUnderground Storage Tanks · 3.7 mi
- MEADOW VALLEY DIVUnderground Storage Tanks · 3.7 mi
- DAVE BAYEUnderground Storage Tanks · 3.9 mi
- CARL PORIORUnderground Storage Tanks · 4.2 mi
- MARVIN NASGOVITZUnderground Storage Tanks · 4.5 mi
- THOMAS M CLARKUnderground Storage Tanks · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Oconto 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 Oconto County.
Total Sites
535
across Oconto County
Risk Level
Elevated
Highest-severity
6 Superfund sites (none NPL-listed)
Sources Checked
across Oconto County
Severity Distribution
across Oconto County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oconto County, two things run higher than the national average across Oconto County — Underground Storage Tanks (378 sites) and CAFO (5 sites). That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Oconto 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 Oconto County average
Your land is one point inside Oconto County
Everything above resolves to Oconto County as a whole — one PHZM band and one county frost record, read across 638K 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 Oconto County Average
Oconto County Average
- ●USDA Zones 5a, averaged across Oconto County
- ●One soil character for all of Oconto County
- ●Frost dates read at Oconto County's scale: May 2 to Oct 13
YOUR Parcel
- ✓Your exact zone, not Oconto County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Oconto County
Pull a site-specific report for your exact address in Oconto County, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Oconto County averages can't show:
We read public map data around Oconto County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oconto County average
How we know this about Oconto 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 Oconto County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Oconto County
When does frost risk typically end in Oconto County?
The last hard freeze (28°F) in Oconto County typically lands around May 2, 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 23.
How long is the growing season in Oconto County?
Measured between 28°F hard freezes, Oconto County sees about 164 frost-free days — roughly May 2 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 23 to Sep 29, about 129 days.
Is the soil safe to grow vegetables in Oconto County?
The federal record around Oconto County is a meaningful one — 535 documented sites, mostly Underground Storage Tanks entries (378), the nearest Underground Storage Tanks record about 1.8 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 Oconto County's scale — its 5a band and its 164-day season. Your yard writes its own version of Oconto 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 Wisconsin's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Oconto County’s own scale
9 of the readings below were taken at Oconto County's own scale — its own ~164-day span between 28°F freezes, the 3 most extensive soil series mapped here and 535 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Oconto County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Oconto County's own 28°F hard-freeze dates and its ~164-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Oconto CountyUSDA NRCS SSURGO
- 535 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.8 miles outFederal environmental registers
- Oconto County's boundary and the 638,386 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~164-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Oconto County spans, North Central Hardwood Forests the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Oconto County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Oconto County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Wisconsin grower plans around — written at state scale, so they stay on the state guidefrom Wisconsin
What this page can’t tell you
- How the season shifts across Oconto County — the ~164 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 Oconto County's 638,386 acreswhy one lot differs from the next →
- Which of those 535 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 Oconto Countyread your own land →