Marathon County, in Wisconsin, sits in USDA hardiness zone 4b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, cranberry, turkish rocket, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Marathon County holds more than one microclimate.
Soils and elevations shift across Marathon 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 Marathon County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Marathon County — the short answer
Marathon County, Wisconsin: USDA zone 4b, about 176 days between hard freezes, across 989K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 23
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 16
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~176
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 989K 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 Marathon County's average, not your lot's — a low corner or a tree line moves it. Against Marathon County's 176-day season, see what your own ground reads.
Heat in Marathon County
Across a year, Marathon County accumulates about 1,972 growing degree days above 50°F, about 178 fewer than the middle Wisconsin county — ahead of 21 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 Marathon County
Across Marathon County, the ground is predominantly Alfisols, where Withee, Loyal, and Rietbrock are the most extensive named soil series. The soil is generally somewhat poorly drained with a silt loam surface. Topsoil pH runs about 5.5–5.9, moderately acidic. Rainfall drains through hydrologic group C/D soils.
Soil order
Alfisols
Drainage
Somewhat poorly drained
Prime farmland
30%
Hydric soils
19%
Soil still varies lot by lot — soil types explained.
How the ground varies across Marathon County
The USDA soil survey maps 34% of Marathon County as somewhat poorly drained — but another 64% drains differently: 25% well drained, 15% moderately well drained.
Withee is the most extensive named soil at 11% of mapped acres, then Loyal (9%) and Rietbrock (8%).
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 Marathon County
Each reading below is measured for Marathon 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 Marathon County are somewhat 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 Marathon County runs about pH 5.5–5.9, 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
Season length
MeasuredMarathon County runs about 176 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
MeasuredMarathon 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 Marathon County is in
Marathon County sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Marathon County
We scored all 1,086 plants against Marathon County's own USDA zone 4b and its own 176-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 Marathon County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 16 — 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 Marathon County
- monarch butterfly2 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Marathon County
USGS estimates 78,993 lb of Glyphosate on Marathon County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (64,182 lb) and Acetochlor (60,532 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 Marathon County — and how to grow with it.
We checked the federal record across Marathon County — 1,507 documented sites across 7 of the 9 source types we track.
The most significant on record: 9 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Marathon County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Marathon County
Closest first, across Marathon County. Listing isn't leaking, and distance isn't exposure.
- Beckett FarmUnderground Storage Tanks · 350 ft
- VILAS BODY & CUSTOMBrownfields · 0.6 mi
- HURTIS OIL COUnderground Storage Tanks · 2.0 mi
- MARATHON BUS CO INCUnderground Storage Tanks · 2.0 mi
- HENRY BURMEISTERUnderground Storage Tanks · 2.0 mi
- MARCO CO OP HALDER MILLUnderground Storage Tanks · 2.0 mi
- BUETCH IMPLEMENT INCUnderground Storage Tanks · 2.0 mi
- JAMES BLUMEUnderground Storage Tanks · 2.0 mi
- DEW DROP INNUnderground Storage Tanks · 2.0 mi
- Ronald WadzinskiUnderground Storage Tanks · 2.3 mi
- TOWN OF MARATHONUnderground Storage Tanks · 2.5 mi
- MR-28/06E/03-0509Nitrate · 2.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Marathon 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 Marathon County.
Sources Checked
across Marathon County
Severity Distribution
across Marathon County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Marathon County, Underground Storage Tanks runs higher than the national average — 1,002 sites across Marathon County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Marathon 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 Marathon County average
Your land is one point inside Marathon County
Everything above resolves to Marathon County as a whole — one PHZM band and one county frost record, read across 989K 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 Marathon County Average
Marathon County Average
- ●USDA Zones 4b, averaged across Marathon County
- ●One soil character for all of Marathon County
- ●Frost dates read at Marathon County's scale: Apr 23 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Marathon County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Marathon County
Pull a site-specific report for your exact address in Marathon County, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Marathon County averages can't show:
We read public map data around Marathon County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Marathon County average
How we know this about Marathon 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 Marathon County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Marathon County
When does frost risk typically end in Marathon County?
The last hard freeze (28°F) in Marathon County typically lands around Apr 23, 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 14.
How long is the growing season in Marathon County?
Measured between 28°F hard freezes, Marathon County sees about 176 frost-free days — roughly Apr 23 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 14 to Oct 2, about 141 days.
Is the soil safe to grow vegetables in Marathon County?
The federal record around Marathon County runs heavier than most — 1,507 documented sites, mostly Underground Storage Tanks entries (1,002), the nearest Underground Storage Tanks record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Marathon County's scale — its 4b band and its 176-day season. Your yard writes its own version of Marathon 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 Marathon County’s own scale
9 of the readings below were taken at Marathon County's own scale — its own ~176-day span between 28°F freezes, the 3 most extensive soil series mapped here and 1,507 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Marathon County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Marathon County's own 28°F hard-freeze dates and its ~176-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Marathon CountyUSDA NRCS SSURGO
- 1,507 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
- Marathon County's boundary and the 988,958 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~176-day seasonGrowable Ground crop-matching engine
- Marathon County sitting wholly inside the North Central Hardwood ForestsUS EPA Level III Ecoregions
- Open occurrence records documented in Marathon County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Marathon 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 Marathon County — the ~176 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 Marathon County's 988,958 acreswhy one lot differs from the next →
- Which of those 1,507 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 Marathon Countyread your own land →