Grant County, in Wisconsin, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
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.
Grant 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
Grant County holds more than one microclimate.
Soils and elevations shift across Grant 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 Grant County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Grant County — the short answer
Grant County, Wisconsin: USDA zone 5a, about 189 days between hard freezes, across 734K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 734K 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 Grant County's average, not your lot's — a low corner or a tree line moves it. Against Grant County's 189-day season, see what your own ground reads.
Heat in Grant County
Across a year, Grant County accumulates about 2,423 growing degree days above 50°F, about 273 more than the middle Wisconsin county — ahead of 62 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 Grant County
Across Grant County, the ground is predominantly Alfisols, where Fayette, Newglarus, and Palsgrove are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
18%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Grant County
The USDA soil survey maps 83% of Grant County as well drained — but another 15% drains differently: 8% moderately well drained, 3% somewhat poorly drained.
Fayette is the most extensive named soil at 22% of mapped acres, then Newglarus (14%) and Palsgrove (11%).
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 Grant County
Each reading below is measured for Grant 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 Grant 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 Grant County runs about pH 6.2–6.7, 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
MeasuredGrant County runs about 189 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
MeasuredGrant County sits in USDA hardiness zone 5a.
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 Grant County is in
Grant County sits in the Driftless Area — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Grant County
We scored all 1,086 plants against Grant County's own USDA zone 5a and its own 189-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 Grant 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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (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. 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 Grant County
- Japanese beetle50 documented records
- monarch butterfly80 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Grant County
USGS estimates 232,748 lb of Glyphosate on Grant County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (91,583 lb) and Acetochlor (87,765 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 Grant County — and how to grow with it.
We checked the federal record across Grant County — 926 documented sites across 7 of the 9 source types we track.
The most significant on record: 27 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
Grant 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 Grant County
Closest first, across Grant County. Listing isn't leaking, and distance isn't exposure.
- CENEX LAND O LAKES INCUnderground Storage Tanks · 2100 ft
- PHILIPPS AG CHEMICAL CO INCUnderground Storage Tanks · 2100 ft
- MAJESTIC VIEW DAIRY LLCCAFO · 2100 ft
- Allegiant Oil LLCUnderground Storage Tanks · 2400 ft
- SANITARY CREAMERY CO INCUnderground Storage Tanks · 2400 ft
- ALTERNATIVE RECYCLINGToxics Release Inventory · 2500 ft
- ALTERNATIVE RECYCLINGBrownfields · 2500 ft
- Premier CoopUnderground Storage Tanks · 2500 ft
- WEST END SALVAGEToxics Release Inventory · 0.5 mi
- BRYHANS BODY & PAINT SPECBrownfields · 0.6 mi
- MILPRINT INCBrownfields · 0.6 mi
- MILPRINT INCToxics Release Inventory · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grant 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 Grant County.
Total Sites
926
across Grant County
Risk Level
High
Highest-severity
27 Toxics Release Inventory facilities
Severity Distribution
across Grant County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grant County, two things run higher than the national average across Grant County — Mining (158 sites) and CAFO (9 sites). That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Grant 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 Grant County average
Your land is one point inside Grant County
Everything above resolves to Grant County as a whole — one PHZM band and one county frost record, read across 734K 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 Grant County Average
Grant County Average
- ●USDA Zones 5a, averaged across Grant County
- ●One soil character for all of Grant County
- ●Frost dates read at Grant County's scale: Apr 15 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Grant County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Grant County
Pull a site-specific report for your exact address in Grant County, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grant County averages can't show:
We read public map data around Grant County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grant County average
How we know this about Grant 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 Grant County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Grant County
When does frost risk typically end in Grant County?
The last hard freeze (28°F) in Grant County typically lands around Apr 15, 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 6.
How long is the growing season in Grant County?
Measured between 28°F hard freezes, Grant County sees about 189 frost-free days — roughly Apr 15 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 7, about 154 days.
Is the soil safe to grow vegetables in Grant County?
The federal record around Grant County runs heavier than most — 926 documented sites, mostly Underground Storage Tanks entries (557), the nearest Underground Storage Tanks record about 0.4 miles 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 Grant County's scale — its 5a band and its 189-day season. Your yard writes its own version of Grant 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 Grant County’s own scale
9 of the readings below were taken at Grant County's own scale — its own ~189-day span between 28°F freezes, the 3 most extensive soil series mapped here and 926 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Grant County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Grant County's own 28°F hard-freeze dates and its ~189-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Grant CountyUSDA NRCS SSURGO
- 926 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.4 miles outFederal environmental registers
- Grant County's boundary and the 734,466 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~189-day seasonGrowable Ground crop-matching engine
- Grant County sitting wholly inside the Driftless AreaUS EPA Level III Ecoregions
- Open occurrence records documented in Grant County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Grant 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 Grant County — the ~189 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 Grant County's 734,466 acreswhy one lot differs from the next →
- Which of those 926 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 Grant Countyread your own land →