Thornton, Wisconsin, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cabbage, cranberry, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Thornton, 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 Thornton 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 Thornton — soil, climate, flood, and parcel records. How we handle your address.
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Thornton — the short answer
Thornton, Wisconsin: USDA zone 5a, about 165 days between hard freezes, across 166 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~165
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 166 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 5a is Thornton's average, not your lot's — a low corner or a tree line moves it. Against Thornton's 165-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Thornton
Each reading below is measured for Thornton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredThornton runs about 165 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
MeasuredThornton 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 Thornton is in
Thornton sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Thornton's own centroid rather than borrowed from Shawano County.
What Grows in Thornton
Every plant below cleared Thornton's own zone 5a and its 165-day season. Each card opens that plant's Wisconsin profile. How we score.
Is it too late to plant in Thornton?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — 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.
What's on the federal record near Thornton
Closest first, within ~10 miles of Thornton. Listing isn't leaking, and distance isn't exposure.
- RICHMOND MACHINE SHOPUnderground Storage Tanks · 550 ft
- KRUEGER DAIRY LLCCAFO · 1.4 mi
- CALIBER COLLISION CENTER - SHAWANO 3375Brownfields · 2.2 mi
- Betty KortUnderground Storage Tanks · 3.1 mi
- SHAWANO WATERWORKSPFAS · 3.1 mi
- SHAWANO LK SAN DIST 1PFAS · 3.1 mi
- COOPERATIVE RESOURCES INTERNATIONALBrownfields · 3.2 mi
- Isabelle BlackUnderground Storage Tanks · 3.7 mi
- LITTLE RAPIDS CORP - SHAWANO PAPER MILLBrownfields · 3.7 mi
- LITTLE RAPIDS CORP - SHAWANO PAPER MILLToxics Release Inventory · 3.7 mi
- SHAWANO HYDROBrownfields · 3.8 mi
- Shawano Medical CtrUnderground Storage Tanks · 3.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Thornton'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 Thornton.
Total Sites
381
within ~10 miles of Thornton
Risk Level
Elevated
Highest-severity
11 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Thornton
Severity Distribution
within ~10 miles of Thornton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Thornton, Nitrate runs higher than the national average — 108 sites within ~10 miles of Thornton. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Thornton
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 Thornton average
Your land is one point inside Thornton
Everything above resolves to Thornton as a whole — one PHZM band and one 28°F frost record, read across 166 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 Thornton Average
Thornton Average
- ●USDA Zones 5a, averaged across Thornton
- ●One soil character for all of Thornton
- ●Frost dates read at Thornton's scale: Apr 30 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Thornton's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Thornton
Pull a site-specific report for your exact address in Thornton, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Thornton averages can't show:
We read public map data around Thornton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Thornton average
How we know this about Thornton
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 Thornton’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 Thornton
When does frost risk typically end in Thornton?
The last hard freeze (28°F) in Thornton typically lands around Apr 30, 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 21.
When is the first frost in Thornton?
The first hard freeze (28°F) in Thornton typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 165 days after the spring freeze cleared.
How long is the growing season in Thornton?
Measured between 28°F hard freezes, Thornton sees about 165 frost-free days — roughly Apr 30 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 21 to Sep 28, about 130 days.
Is the soil safe to grow vegetables in Thornton?
The federal record around Thornton is a meaningful one — 381 documented sites, mostly Underground Storage Tanks entries (211), 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 Thornton?
From about Sep 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Thornton's scale — its 5a band and its 165-day season. Your yard writes its own version of Thornton'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 Thornton’s own scale
6 of the readings below were taken at Thornton's own scale — its own ~165-day season between 28°F freezes, the 166 acres it covers and 381 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Thornton's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Thornton's own 28°F hard-freeze dates, about Apr 30 and Oct 12 and the ~165-day span between themNOAA 1991–2020 Climate Normals
- 381 documented contamination sites on the federal record near Thornton, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Thornton's boundary and the 166 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~165-day seasonGrowable Ground crop-matching engine
- The ecoregion at Thornton's own centroid, the North Central Hardwood ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Thornton's 166 acres read through its county's SSURGO summaryfrom Shawano County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Shawano 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 Shawano County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Thornton's 166 acreswhy one lot differs from the next →
- Which side of Thornton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 166 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 Thornton-wide figureread your own land →
More in Wisconsin
Wider growing context
What grows across WisconsinThornton sits outside our named growing regions, so Wisconsin as a whole is its closest context here.