Union Center, Wisconsin, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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 Union Center, 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 Union Center 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 Union Center — soil, climate, flood, and parcel records. How we handle your address.
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Union Center — the short answer
Union Center, Wisconsin: USDA zone 4b, about 170 days between hard freezes, across 527 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~170
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 527 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 Union Center's average, not your lot's — a low corner or a tree line moves it. Against Union Center's 170-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Union Center
Each reading below is measured for Union Center itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredUnion Center runs about 170 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
MeasuredUnion Center 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 Union Center is in
Union Center sits in the Driftless Area — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Union Center's own centroid, and it is not what its county reads: Juneau County is mostly North Central Hardwood Forests. The wider page above you is answering a different question about different ground.
What Grows in Union Center
Every plant below cleared Union Center's own zone 4b and its 170-day season. Each card opens that plant's Wisconsin profile. How we score.
Is it too late to plant in Union Center?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 14 — 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 Union Center
Closest first, within ~10 miles of Union Center. Listing isn't leaking, and distance isn't exposure.
- Heding Trucking ServiceUnderground Storage Tanks · 450 ft
- STEVE HELLPAPUnderground Storage Tanks · 550 ft
- Kwik Trip #847Underground Storage Tanks · 850 ft
- LAND O LAKES- ANIMAL MILK SOLUTIONSToxics Release Inventory · 950 ft
- PRESTON SALES & SERVICES INCUnderground Storage Tanks · 1100 ft
- JAMES SULLIVANUnderground Storage Tanks · 1300 ft
- BRIAN SCHOENLEBERUnderground Storage Tanks · 1300 ft
- TOWN OF WONEWOC GARAGEUnderground Storage Tanks · 1600 ft
- WIS DAIRIES PROPERTYUnderground Storage Tanks · 1600 ft
- TOWN OF WONEWOCUnderground Storage Tanks · 1600 ft
- W CARSON METTELUnderground Storage Tanks · 1700 ft
- D & D Farm SupplyUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Union Center'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 Union Center.
Total Sites
162
within ~10 miles of Union Center
Risk Level
Moderate
Highest-severity
8 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Union Center
Severity Distribution
within ~10 miles of Union Center
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Union Center, Underground Storage Tanks runs higher than the national average — 119 sites within ~10 miles of Union Center. 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 Union Center
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 Union Center average
Your land is one point inside Union Center
Everything above resolves to Union Center as a whole — one PHZM band and one 28°F frost record, read across 527 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 Union Center Average
Union Center Average
- ●USDA Zones 4b, averaged across Union Center
- ●One soil character for all of Union Center
- ●Frost dates read at Union Center's scale: Apr 27 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Union Center's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Union Center
Pull a site-specific report for your exact address in Union Center, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Union Center averages can't show:
We read public map data around Union Center — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Union Center average
How we know this about Union Center
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 Union Center’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 Union Center
When does frost risk typically end in Union Center?
The last hard freeze (28°F) in Union Center typically lands around Apr 27, 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 18.
When is the first frost in Union Center?
The first hard freeze (28°F) in Union Center typically arrives around Oct 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 30, so the watching starts about Sep 14 — about 170 days after the spring freeze cleared.
How long is the growing season in Union Center?
Measured between 28°F hard freezes, Union Center sees about 170 frost-free days — roughly Apr 27 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Sep 30, about 135 days.
Is the soil safe to grow vegetables in Union Center?
The federal record around Union Center shows 162 documented sites, mostly Underground Storage Tanks entries (119), the nearest Underground Storage Tanks record under a tenth of a mile out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Union Center?
From about Sep 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Union Center's scale — its 4b band and its 170-day season. Your yard writes its own version of Union Center'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 Union Center’s own scale
6 of the readings below were taken at Union Center's own scale — its own ~170-day season between 28°F freezes, the 527 acres it covers and 162 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Union Center's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Union Center's own 28°F hard-freeze dates, about Apr 27 and Oct 14 and the ~170-day span between themNOAA 1991–2020 Climate Normals
- 162 documented contamination sites on the federal record near Union Center, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Union Center's boundary and the 527 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~170-day seasonGrowable Ground crop-matching engine
- Union Center sits in the Driftless Area — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Union Center's 527 acres read through its county's SSURGO summaryfrom Juneau County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Juneau 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 Juneau County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Union Center's 527 acreswhy one lot differs from the next →
- Which side of Union Center you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 527 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Union Center-wide figureread your own land →
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