Star Prairie, Wisconsin, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include cabbage, cranberry, turkish rocket, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Star Prairie, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Star Prairie lot. 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 Star Prairie — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Star Prairie — the short answer
Star Prairie, Wisconsin: USDA zone 4b, about 180 days between hard freezes, across 1K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~180
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 Star Prairie's average, not your lot's — a low corner or a tree line moves it. Against Star Prairie's 180-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Star Prairie
Each reading below is measured for Star Prairie itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredStar Prairie runs about 180 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
MeasuredStar Prairie 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 Star Prairie is in
Star Prairie sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Star Prairie's own centroid, and it is not what its county reads: St. Croix County is mostly Western Corn Belt Plains. The wider page above you is answering a different question about different ground.
What Grows in Star Prairie
Every plant below cleared Star Prairie's own zone 4b and its 180-day season. Each card opens that plant's Wisconsin profile. How we score.






























Is it too late to plant in Star Prairie?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 18 — 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.
What's on the federal record near Star Prairie
Closest first, within ~10 miles of Star Prairie. Listing isn't leaking, and distance isn't exposure.
- ST CROIX COUNTY HWY DEPTUnderground Storage Tanks · 650 ft
- SKOGLUND OIL CO INCUnderground Storage Tanks · 750 ft
- DAVES SERVICE CENTERUnderground Storage Tanks · 800 ft
- DAVES SERVICE CENTERBrownfields · 800 ft
- TOM THUMB FOOD MARKETSUnderground Storage Tanks · 950 ft
- HILLSIDE SMALL ENGINE REPAIRBrownfields · 1000 ft
- APPLE RIVER FARMSUnderground Storage Tanks · 0.5 mi
- Star Prairie Convenience IncUnderground Storage Tanks · 0.7 mi
- NUTZMANN CHUCKBrownfields · 1.1 mi
- SC-31/17W/07-0697Nitrate · 1.1 mi
- SC-29/18W/03-0318Nitrate · 2.1 mi
- PRECISION AG SERVICES LLCBrownfields · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Star Prairie'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 Star Prairie.
Total Sites
315
within ~10 miles of Star Prairie
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Star Prairie
Severity Distribution
within ~10 miles of Star Prairie
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 Star Prairie
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 Star Prairie average
Your land is one point inside Star Prairie
Everything above resolves to Star Prairie as a whole — one PHZM band and one 28°F frost record, read across 1K 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 town 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 local average.
Your Lot vs the Star Prairie Average
Star Prairie Average
- ●USDA Zones 4b, averaged across Star Prairie
- ●One soil character for all of Star Prairie
- ●Frost dates read at Star Prairie's scale: Apr 21 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Star Prairie's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Star Prairie
Pull a site-specific report for your exact address in Star Prairie, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Star Prairie averages can't show:
We read public map data around Star Prairie — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Star Prairie average
How we know this about Star Prairie
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Star Prairie’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Star Prairie
When does frost risk typically end in Star Prairie?
The last hard freeze (28°F) in Star Prairie typically lands around Apr 21, 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 12.
When is the first frost in Star Prairie?
The first hard freeze (28°F) in Star Prairie typically arrives around Oct 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 4, so the watching starts about Sep 18 — about 180 days after the spring freeze cleared.
How long is the growing season in Star Prairie?
Measured between 28°F hard freezes, Star Prairie sees about 180 frost-free days — roughly Apr 21 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Oct 4, about 145 days.
Is the soil safe to grow vegetables in Star Prairie?
The federal record around Star Prairie is a meaningful one — 315 documented sites, mostly Underground Storage Tanks entries (131), the nearest Underground Storage Tanks record about 0.1 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.
How do I protect my plants from frost in Star Prairie?
From about Sep 18 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 18 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Star Prairie's scale — its 4b band and its 180-day season. Your yard writes its own version of Star Prairie's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Star Prairie’s own scale
6 of the readings below were taken at Star Prairie's own scale — its own ~180-day season between 28°F freezes, the 1,372 acres it covers and 315 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Star Prairie's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Star Prairie's own 28°F hard-freeze dates, about Apr 21 and Oct 18 and the ~180-day span between themNOAA 1991–2020 Climate Normals
- 315 documented contamination sites on the federal record near Star Prairie, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Star Prairie's boundary and the 1,372 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~180-day seasonGrowable Ground crop-matching engine
- Star Prairie sits in the North Central Hardwood Forests — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Star Prairie's 1,372 acres read through its county's SSURGO summaryfrom St. Croix County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom St. Croix County
- The growing challenges every Wisconsin grower plans around — written at state scale, so they stay on the state guidefrom Wisconsin
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom St. Croix County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Star Prairie's 1,372 acreswhy one lot differs from the next →
- Which side of Star Prairie you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,372 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Star Prairie-wide figureread your own land →
More in Wisconsin
Wider growing context
What grows across WisconsinStar Prairie sits outside our named growing regions, so Wisconsin as a whole is its closest context here.
Nearby growing guides
