Gwinn, Michigan, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Gwinn, 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 Gwinn 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 Gwinn — soil, climate, flood, and parcel records. How we handle your address.
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Gwinn — the short answer
Gwinn, Michigan: USDA zone 5a, about 151 days between hard freezes, across 2K acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~151
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 Gwinn's average, not your lot's — a low corner or a tree line moves it. Against Gwinn's 151-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Gwinn
Each reading below is measured for Gwinn itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGwinn runs about 151 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
MeasuredGwinn 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 Gwinn is in
Gwinn sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Gwinn's own centroid rather than borrowed from Marquette County.
What Grows in Gwinn
Every plant below cleared Gwinn's own zone 5a and its 151-day season. Each card opens that plant's Michigan profile. How we score.
Is it too late to plant in Gwinn?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 10 — 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 Gwinn
Closest first, within ~10 miles of Gwinn. Listing isn't leaking, and distance isn't exposure.
- Norms Service CenterUnderground Storage Tanks · 850 ft
- Vacant LotUnderground Storage Tanks · 1000 ft
- Elliott Sheet Metal, IncUnderground Storage Tanks · 1000 ft
- NORM'S SERVICE CENTER INCBrownfields · 1200 ft
- Gwinn Schools Bus GarageUnderground Storage Tanks · 2200 ft
- Modeltown ExpressUnderground Storage Tanks · 2300 ft
- Gwinn District GarageUnderground Storage Tanks · 2400 ft
- JOE & SONS SERVICE CENTER LLCBrownfields · 0.5 mi
- Joe & Son ServiceUnderground Storage Tanks · 0.5 mi
- Forsyth TwpUnderground Storage Tanks · 0.5 mi
- LYNNS KORNER KAFE/GWINN RECYCLING INCBrownfields · 0.6 mi
- FORSYTH TOWNSHIP GARAGEBrownfields · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Gwinn'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 Gwinn.
Total Sites
107
within ~10 miles of Gwinn
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Gwinn
Severity Distribution
within ~10 miles of Gwinn
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Gwinn, Nitrate runs higher than the national average — 56 sites within ~10 miles of Gwinn. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Gwinn
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 Gwinn average
Your land is one point inside Gwinn
Everything above resolves to Gwinn as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Gwinn Average
Gwinn Average
- ●USDA Zones 5a, averaged across Gwinn
- ●One soil character for all of Gwinn
- ●Frost dates read at Gwinn's scale: May 12 to Oct 10
YOUR Parcel
- ✓Your exact zone, not Gwinn's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Gwinn
Pull a site-specific report for your exact address in Gwinn, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Gwinn averages can't show:
We read public map data around Gwinn — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Gwinn average
How we know this about Gwinn
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 Gwinn’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 Gwinn
When does frost risk typically end in Gwinn?
The last hard freeze (28°F) in Gwinn typically lands around May 12, 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 Jun 2.
When is the first frost in Gwinn?
The first hard freeze (28°F) in Gwinn typically arrives around Oct 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 26, so the watching starts about Sep 10 — about 151 days after the spring freeze cleared.
How long is the growing season in Gwinn?
Measured between 28°F hard freezes, Gwinn sees about 151 frost-free days — roughly May 12 through Oct 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 2 to Sep 26, about 116 days.
Is the soil safe to grow vegetables in Gwinn?
The federal record around Gwinn is a meaningful one — 107 documented sites, mostly Nitrate 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 Gwinn?
From about Sep 10 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Gwinn's scale — its 5a band and its 151-day season. Your yard writes its own version of Gwinn'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 Gwinn’s own scale
6 of the readings below were taken at Gwinn's own scale — its own ~151-day season between 28°F freezes, the 1,800 acres it covers and 107 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Gwinn's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Gwinn's own 28°F hard-freeze dates, about May 12 and Oct 10 and the ~151-day span between themNOAA 1991–2020 Climate Normals
- 107 documented contamination sites on the federal record near Gwinn, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Gwinn's boundary and the 1,800 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~151-day seasonGrowable Ground crop-matching engine
- The ecoregion at Gwinn'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 Gwinn's 1,800 acres read through its county's SSURGO summaryfrom Marquette County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Marquette County
- The growing challenges every Michigan grower plans around — written at state scale, so they stay on the state guidefrom Michigan
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Marquette County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Gwinn's 1,800 acreswhy one lot differs from the next →
- Which side of Gwinn you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,800 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 Gwinn-wide figureread your own land →
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