Washburn County, in Wisconsin, sits in USDA hardiness zone 4a — 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.
Washburn County lies within the Northwoods (Northern Wisconsin) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Washburn County holds more than one microclimate.
Soils and elevations shift across Washburn 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 Washburn County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Washburn County — the short answer
Washburn County, Wisconsin: USDA zone 4a, about 156 days between hard freezes, across 510K acres.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 3
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 6
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~156
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 510K 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 4a is Washburn County's average, not your lot's — a low corner or a tree line moves it. Against Washburn County's 156-day season, see what your own ground reads.
Heat in Washburn County
Across a year, Washburn County accumulates about 1,942 growing degree days above 50°F, about 208 fewer than the middle Wisconsin county — ahead of 19 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 Washburn County
Across Washburn County, the ground is predominantly Entisols, where Menahga, Graycalm, and Grayling are the most extensive named soil series. The soil is generally moderately well drained with a sandy loam surface. Topsoil pH runs about 5.0–5.9, strongly acidic. Rainfall drains through hydrologic group A soils.
Soil order
Entisols
Drainage
Moderately well drained
Prime farmland
8%
Hydric soils
17%
Soil still varies lot by lot — soil types explained.
How the ground varies across Washburn County
The USDA soil survey maps 24% of Washburn County as moderately well drained — but another 70% drains differently: 23% well drained, 16% excessively drained.
Menahga is the most extensive named soil at 12% of mapped acres, then Graycalm (7%) and Grayling (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 Washburn County
Each reading below is measured for Washburn 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 Washburn County are moderately well drained, in hydrologic group A — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Washburn County runs about pH 5.0–5.9, 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 17% of Washburn 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
MeasuredWashburn County runs about 156 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 Washburn County is in
Washburn County spans 2 EPA Level III ecoregions — Northern Lakes and Forests (84%) and North Central Hardwood Forests (16%). 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 Washburn County
We scored all 1,086 plants against Washburn County's own USDA zone 4a and its own 156-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 Washburn County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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 Washburn County
- Japanese beetle1 documented records
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Washburn County
USGS estimates 29,044 lb of Glyphosate on Washburn County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (7,926 lb) and Atrazine (7,725 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 Washburn County — and how to grow with it.
We checked the federal record across Washburn County — 304 documented sites across 6 of the 9 source types we track.
The most significant on record: 2 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Washburn 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 Washburn County
Closest first, across Washburn County. Listing isn't leaking, and distance isn't exposure.
- COONS STOREUnderground Storage Tanks · 0.5 mi
- Mac Taylors StoreUnderground Storage Tanks · 1.2 mi
- NORTHLAND ELECTRONICSBrownfields · 1.3 mi
- BUBBAS MACHINE SHOPBrownfields · 1.4 mi
- B & M SERVICEUnderground Storage Tanks · 1.6 mi
- ICO STORE #156Underground Storage Tanks · 1.7 mi
- Trego Travel CenterUnderground Storage Tanks · 1.7 mi
- Schultzs AirportUnderground Storage Tanks · 1.7 mi
- TREGO GENERAL STOREUnderground Storage Tanks · 1.7 mi
- Lampson TavernUnderground Storage Tanks · 1.7 mi
- GLEN GRIMESUnderground Storage Tanks · 1.7 mi
- KEN LECKELUnderground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Washburn 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 Washburn County.
Total Sites
304
across Washburn County
Risk Level
Elevated
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
across Washburn County
Severity Distribution
across Washburn County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Washburn County, Underground Storage Tanks runs higher than the national average — 190 sites across Washburn County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Washburn 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 Washburn County average
Your land is one point inside Washburn County
Everything above resolves to Washburn County as a whole — one PHZM band and one county frost record, read across 510K 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 Washburn County Average
Washburn County Average
- ●USDA Zones 4a, averaged across Washburn County
- ●One soil character for all of Washburn County
- ●Frost dates read at Washburn County's scale: May 3 to Oct 6
YOUR Parcel
- ✓Your exact zone, not Washburn County's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Washburn County
Pull a site-specific report for your exact address in Washburn County, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Washburn County averages can't show:
We read public map data around Washburn County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Washburn County average
How we know this about Washburn 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 Washburn County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Washburn County
When does frost risk typically end in Washburn County?
The last hard freeze (28°F) in Washburn County typically lands around May 3, 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 24.
How long is the growing season in Washburn County?
Measured between 28°F hard freezes, Washburn County sees about 156 frost-free days — roughly May 3 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 24 to Sep 22, about 121 days.
Is the soil safe to grow vegetables in Washburn County?
The federal record around Washburn County is a meaningful one — 304 documented sites, mostly Underground Storage Tanks entries (190), the nearest Underground Storage Tanks record about 0.5 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 Washburn County's scale — its 4a band and its 156-day season. Your yard writes its own version of Washburn 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 Washburn County’s own scale
9 of the readings below were taken at Washburn County's own scale — its own ~156-day span between 28°F freezes, the 3 most extensive soil series mapped here and 304 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Washburn County's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Washburn County's own 28°F hard-freeze dates and its ~156-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Washburn CountyUSDA NRCS SSURGO
- 304 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.5 miles outFederal environmental registers
- Washburn County's boundary and the 510,153 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~156-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Washburn County spans, Northern Lakes and Forests the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Washburn County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Washburn 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 Washburn County — the ~156 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 Washburn County's 510,153 acreswhy one lot differs from the next →
- Which of those 304 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 Washburn Countyread your own land →