Markesan, Wisconsin, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
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 Markesan, 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 Markesan 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 Markesan — soil, climate, flood, and parcel records. How we handle your address.
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Markesan — the short answer
Markesan, Wisconsin: USDA zone 5a, about 182 days between hard freezes, across 1K acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~182
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City 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 5a is Markesan's average, not your lot's — a low corner or a tree line moves it. Against Markesan's 182-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Markesan
Each reading below is measured for Markesan itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredMarkesan runs about 182 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
MeasuredMarkesan 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 Markesan is in
Markesan sits in the Southeastern Wisconsin Till Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Markesan's own centroid rather than borrowed from Green Lake County.
What Grows in Markesan
Every plant below cleared Markesan's own zone 5a and its 182-day season. Each card opens that plant's Wisconsin profile. How we score.






























Is it too late to plant in Markesan?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — 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 Markesan
Spotted lanternfly documented 8 miles from Markesan, first recorded 2023. What to watch for.
What's on the federal record near Markesan
Closest first, within ~10 miles of Markesan. Listing isn't leaking, and distance isn't exposure.
- Markesan Middle SchoolUnderground Storage Tanks · 200 ft
- DENNIS BREIDENBACHUnderground Storage Tanks · 400 ft
- DOLLAR GENERAL STORE #30631Brownfields · 650 ft
- BALLWEG IMPL CO INCUnderground Storage Tanks · 750 ft
- Landmark Services CoopUnderground Storage Tanks · 750 ft
- CONDON OILBrownfields · 1300 ft
- Nowatzski FieldUnderground Storage Tanks · 1400 ft
- RONALD M POWLESSUnderground Storage Tanks · 1400 ft
- RUSSELL SCHWANDTUnderground Storage Tanks · 1400 ft
- WALTER NOWATZSKIUnderground Storage Tanks · 1400 ft
- KENNETH L BATESUnderground Storage Tanks · 1400 ft
- SEVERSON BUILDERS INCUnderground Storage Tanks · 1400 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Markesan'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 Markesan.
Total Sites
234
within ~10 miles of Markesan
Risk Level
Elevated
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Markesan
Severity Distribution
within ~10 miles of Markesan
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Markesan, two things run higher than the national average within ~10 miles of Markesan — CAFO (4 sites) and Underground Storage Tanks (169 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Markesan
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 Markesan average
Your land is one point inside Markesan
Everything above resolves to Markesan 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 city 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 Markesan Average
Markesan Average
- ●USDA Zones 5a, averaged across Markesan
- ●One soil character for all of Markesan
- ●Frost dates read at Markesan's scale: Apr 18 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Markesan's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Markesan
Pull a site-specific report for your exact address in Markesan, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Markesan averages can't show:
We read public map data around Markesan — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Markesan average
How we know this about Markesan
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Markesan’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 city grain anywhere on this page — there is no city-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 Markesan
When does frost risk typically end in Markesan?
The last hard freeze (28°F) in Markesan typically lands around Apr 18, 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 9.
When is the first frost in Markesan?
The first hard freeze (28°F) in Markesan typically arrives around Oct 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 3, so the watching starts about Sep 17 — about 182 days after the spring freeze cleared.
How long is the growing season in Markesan?
Measured between 28°F hard freezes, Markesan sees about 182 frost-free days — roughly Apr 18 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 9 to Oct 3, about 147 days.
Is the soil safe to grow vegetables in Markesan?
The federal record around Markesan is a meaningful one — 234 documented sites, mostly Underground Storage Tanks entries (169), the nearest Underground Storage Tanks record under a tenth of a mile 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 Markesan?
From about Sep 17 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Markesan's scale — its 5a band and its 182-day season. Your yard writes its own version of Markesan'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 Markesan’s own scale
7 of the readings below were taken at Markesan's own scale — its own ~182-day season between 28°F freezes, the 1,487 acres it covers and 234 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Markesan's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Markesan's own 28°F hard-freeze dates, about Apr 18 and Oct 17 and the ~182-day span between themNOAA 1991–2020 Climate Normals
- 234 documented contamination sites on the federal record near Markesan, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Markesan's boundary and the 1,487 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~182-day seasonGrowable Ground crop-matching engine
- The ecoregion at Markesan's own centroid, the Southeastern Wisconsin Till PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Markesanlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Markesan's 1,487 acres read through its county's SSURGO summaryfrom Green Lake County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Green Lake 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 Green Lake County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Markesan's 1,487 acreswhy one lot differs from the next →
- Which side of Markesan you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,487 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 Markesan-wide figureread your own land →
More in Wisconsin
Wider growing context
What grows across WisconsinMarkesan sits outside our named growing regions, so Wisconsin as a whole is its closest context here.
Nearby growing guides
