Chelsea, Wisconsin, sits in USDA hardiness zone 4a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, cranberry, turkish rocket, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Chelsea, 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 Chelsea 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 Chelsea — soil, climate, flood, and parcel records. How we handle your address.
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Chelsea — the short answer
Chelsea, Wisconsin: USDA zone 4a, about 152 days between hard freezes, across 296 acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~152
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 296 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 4a is Chelsea's average, not your lot's — a low corner or a tree line moves it. Against Chelsea's 152-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Chelsea
Each reading below is measured for Chelsea itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredChelsea runs about 152 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
MeasuredChelsea sits in USDA hardiness zone 4a.
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 Chelsea is in
Chelsea sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Chelsea's own centroid rather than borrowed from Taylor County.
What Grows in Chelsea
Every plant below cleared Chelsea's own zone 4a and its 152-day season. Each card opens that plant's Wisconsin profile. How we score.
Is it too late to plant in Chelsea?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Chelsea
Closest first, within ~10 miles of Chelsea. Listing isn't leaking, and distance isn't exposure.
- BRANDNER TRUCKING INCUnderground Storage Tanks · 1000 ft
- WALTER J LEONHARDTUnderground Storage Tanks · 1100 ft
- TA-33/02E/30-0009Nitrate · 2.0 mi
- George HaenelUnderground Storage Tanks · 2.3 mi
- RINEHART REPAIRBrownfields · 2.4 mi
- THUMS CONS INCUnderground Storage Tanks · 2.7 mi
- Donald ZimmermanUnderground Storage Tanks · 3.2 mi
- ZENTNER TRUCKING INCUnderground Storage Tanks · 3.4 mi
- TA-32/01E/24-0226Nitrate · 3.8 mi
- MARK S TLUSTYUnderground Storage Tanks · 4.1 mi
- BRANDNER FOREST PRODUCTS INCUnderground Storage Tanks · 4.2 mi
- TOWN OF WESTBOROUnderground Storage Tanks · 4.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Chelsea'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 Chelsea.
Total Sites
75
within ~10 miles of Chelsea
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Chelsea
Severity Distribution
within ~10 miles of Chelsea
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Chelsea, Underground Storage Tanks runs higher than the national average — 56 sites within ~10 miles of Chelsea. 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 Chelsea
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 Chelsea average
Your land is one point inside Chelsea
Everything above resolves to Chelsea as a whole — one PHZM band and one 28°F frost record, read across 296 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 Chelsea Average
Chelsea Average
- ●USDA Zones 4a, averaged across Chelsea
- ●One soil character for all of Chelsea
- ●Frost dates read at Chelsea's scale: May 7 to Oct 6
YOUR Parcel
- ✓Your exact zone, not Chelsea's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Chelsea
Pull a site-specific report for your exact address in Chelsea, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Chelsea averages can't show:
We read public map data around Chelsea — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Chelsea average
How we know this about Chelsea
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 Chelsea’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 Chelsea
When does frost risk typically end in Chelsea?
The last hard freeze (28°F) in Chelsea typically lands around May 7, 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 28.
When is the first frost in Chelsea?
The first hard freeze (28°F) in Chelsea typically arrives around Oct 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 22, so the watching starts about Sep 6 — about 152 days after the spring freeze cleared.
How long is the growing season in Chelsea?
Measured between 28°F hard freezes, Chelsea sees about 152 frost-free days — roughly May 7 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 22, about 117 days.
Is the soil safe to grow vegetables in Chelsea?
The federal record around Chelsea is a meaningful one — 75 documented sites, mostly Underground Storage Tanks entries (56), the nearest Underground Storage Tanks record about 0.2 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 Chelsea?
From about Sep 6 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Chelsea's scale — its 4a band and its 152-day season. Your yard writes its own version of Chelsea'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 Chelsea’s own scale
6 of the readings below were taken at Chelsea's own scale — its own ~152-day season between 28°F freezes, the 296 acres it covers and 75 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Chelsea's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Chelsea's own 28°F hard-freeze dates, about May 7 and Oct 6 and the ~152-day span between themNOAA 1991–2020 Climate Normals
- 75 documented contamination sites on the federal record near Chelsea, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Chelsea's boundary and the 296 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~152-day seasonGrowable Ground crop-matching engine
- The ecoregion at Chelsea's own centroid, the Northern Lakes and ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Chelsea's 296 acres read through its county's SSURGO summaryfrom Taylor County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Taylor 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 Taylor County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Chelsea's 296 acreswhy one lot differs from the next →
- Which side of Chelsea you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 296 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Chelsea-wide figureread your own land →
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