Grand Marsh, Wisconsin, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
The conditions favor cabbage, cranberry, turkish rocket, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Grand Marsh, 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 Grand Marsh 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 Grand Marsh — soil, climate, flood, and parcel records. How we handle your address.
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Grand Marsh — the short answer
Grand Marsh, Wisconsin: USDA zone 4b, about 170 days between hard freezes, across 773 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~170
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 773 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 Grand Marsh's average, not your lot's — a low corner or a tree line moves it. Against Grand Marsh's 170-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grand Marsh
Each reading below is measured for Grand Marsh itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrand Marsh 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
MeasuredGrand Marsh 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 Grand Marsh is in
Grand Marsh sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Grand Marsh's own centroid rather than borrowed from Adams County.
What Grows in Grand Marsh
Every plant below cleared Grand Marsh'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 Grand Marsh?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 15 — 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 Grand Marsh
Closest first, within ~10 miles of Grand Marsh. Listing isn't leaking, and distance isn't exposure.
- AD-16/07E/07-0110Nitrate · 550 ft
- M JANSSENUnderground Storage Tanks · 650 ft
- SHASKIE WELDINGUnderground Storage Tanks · 650 ft
- KOPSTEINS GARAGEUnderground Storage Tanks · 750 ft
- NEW CHESTER FIRE DEPTUnderground Storage Tanks · 800 ft
- GRAND MARSH TRANS ENTERPRIZESUnderground Storage Tanks · 2600 ft
- JOSEPH EMSUnderground Storage Tanks · 1.0 mi
- ARTHUR OVERGAARDUnderground Storage Tanks · 1.9 mi
- NEW CHESTER DAIRY LLCCAFO · 1.9 mi
- Gary Bula Farms IncUnderground Storage Tanks · 2.0 mi
- Wallendal Supply IncUnderground Storage Tanks · 2.1 mi
- Wisconsin River Power CoUnderground Storage Tanks · 2.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grand Marsh'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 Grand Marsh.
Total Sites
154
within ~10 miles of Grand Marsh
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Grand Marsh
Severity Distribution
within ~10 miles of Grand Marsh
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grand Marsh, two things run higher than the national average within ~10 miles of Grand Marsh — CAFO (3 sites) and Underground Storage Tanks (113 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Grand Marsh
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 Grand Marsh average
Your land is one point inside Grand Marsh
Everything above resolves to Grand Marsh as a whole — one PHZM band and one 28°F frost record, read across 773 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 Grand Marsh Average
Grand Marsh Average
- ●USDA Zones 4b, averaged across Grand Marsh
- ●One soil character for all of Grand Marsh
- ●Frost dates read at Grand Marsh's scale: Apr 28 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Grand Marsh's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grand Marsh
Pull a site-specific report for your exact address in Grand Marsh, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grand Marsh averages can't show:
We read public map data around Grand Marsh — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grand Marsh average
How we know this about Grand Marsh
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 Grand Marsh’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 Grand Marsh
When does frost risk typically end in Grand Marsh?
The last hard freeze (28°F) in Grand Marsh typically lands around Apr 28, 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 19.
When is the first frost in Grand Marsh?
The first hard freeze (28°F) in Grand Marsh typically arrives around Oct 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 1, so the watching starts about Sep 15 — about 170 days after the spring freeze cleared.
How long is the growing season in Grand Marsh?
Measured between 28°F hard freezes, Grand Marsh sees about 170 frost-free days — roughly Apr 28 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Oct 1, about 135 days.
Is the soil safe to grow vegetables in Grand Marsh?
The federal record around Grand Marsh shows 154 documented sites, mostly Underground Storage Tanks entries (113), the nearest Nitrate record about 0.1 miles 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 Grand Marsh?
From about Sep 15 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 15 (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 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Grand Marsh's scale — its 4b band and its 170-day season. Your yard writes its own version of Grand Marsh'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 Grand Marsh’s own scale
6 of the readings below were taken at Grand Marsh's own scale — its own ~170-day season between 28°F freezes, the 773 acres it covers and 154 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grand Marsh's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Grand Marsh's own 28°F hard-freeze dates, about Apr 28 and Oct 15 and the ~170-day span between themNOAA 1991–2020 Climate Normals
- 154 documented contamination sites on the federal record near Grand Marsh, the closest Nitrate record about 0.1 miles out from the town centreFederal environmental registers
- Grand Marsh's boundary and the 773 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~170-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grand Marsh'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 Grand Marsh's 773 acres read through its county's SSURGO summaryfrom Adams County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Adams 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 Adams County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grand Marsh's 773 acreswhy one lot differs from the next →
- Which side of Grand Marsh you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 773 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Grand Marsh-wide figureread your own land →
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