Posen, Michigan, sits in USDA hardiness zone 5b — 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, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Posen, 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 Posen 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 Posen — soil, climate, flood, and parcel records. How we handle your address.
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Posen — the short answer
Posen, Michigan: USDA zone 5b, about 159 days between hard freezes, across 639 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~159
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 639 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 5b is Posen's average, not your lot's — a low corner or a tree line moves it. Against Posen's 159-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Posen
Each reading below is measured for Posen itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPosen runs about 159 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
MeasuredPosen sits in USDA hardiness zone 5b.
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 Posen is in
Posen sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Posen's own centroid rather than borrowed from Presque Isle County.
What Grows in Posen
Every plant below cleared Posen's own zone 5b and its 159-day season. Each card opens that plant's Michigan profile. How we score.
Is it too late to plant in Posen?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 16 — 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 Posen
Closest first, within ~10 miles of Posen. Listing isn't leaking, and distance isn't exposure.
- Vinces SunocoUnderground Storage Tanks · 100 ft
- Huron Oil Co LLCUnderground Storage Tanks · 250 ft
- Greg B. SmithUnderground Storage Tanks · 500 ft
- E & Ts Party StoreUnderground Storage Tanks · 500 ft
- Card Reader LLCUnderground Storage Tanks · 650 ft
- FAMILY DOLLAR STORESBrownfields · 700 ft
- Presque Isle Cnty Road CommissionUnderground Storage Tanks · 1000 ft
- Posen EZ MartUnderground Storage Tanks · 1600 ft
- Posen Consolidate School Dist #9Underground Storage Tanks · 2000 ft
- COUNTY OF PRESQUE ISLE ROAD COMMISSIONBrownfields · 2400 ft
- Mels SunocoUnderground Storage Tanks · 2600 ft
- Wilks FarmUnderground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Posen'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 Posen.
Severity Distribution
within ~10 miles of Posen
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Posen, Underground Storage Tanks runs higher than the national average — 26 sites within ~10 miles of Posen. 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 Posen
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 Posen average
Your land is one point inside Posen
Everything above resolves to Posen as a whole — one PHZM band and one 28°F frost record, read across 639 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 Posen Average
Posen Average
- ●USDA Zones 5b, averaged across Posen
- ●One soil character for all of Posen
- ●Frost dates read at Posen's scale: May 10 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Posen's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Posen
Pull a site-specific report for your exact address in Posen, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Posen averages can't show:
We read public map data around Posen — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Posen average
How we know this about Posen
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 Posen’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 Posen
When does frost risk typically end in Posen?
The last hard freeze (28°F) in Posen typically lands around May 10, 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 31.
When is the first frost in Posen?
The first hard freeze (28°F) in Posen typically arrives around Oct 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 2, so the watching starts about Sep 16 — about 159 days after the spring freeze cleared.
How long is the growing season in Posen?
Measured between 28°F hard freezes, Posen sees about 159 frost-free days — roughly May 10 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 31 to Oct 2, about 124 days.
Is the soil safe to grow vegetables in Posen?
The federal record around Posen is light — 39 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (26), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Posen?
From about Sep 16 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Posen's scale — its 5b band and its 159-day season. Your yard writes its own version of Posen'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 Posen’s own scale
6 of the readings below were taken at Posen's own scale — its own ~159-day season between 28°F freezes, the 639 acres it covers and 39 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Posen's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Posen's own 28°F hard-freeze dates, about May 10 and Oct 16 and the ~159-day span between themNOAA 1991–2020 Climate Normals
- 39 documented contamination sites on the federal record near Posen, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Posen's boundary and the 639 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~159-day seasonGrowable Ground crop-matching engine
- The ecoregion at Posen'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 Posen's 639 acres read through its county's SSURGO summaryfrom Presque Isle County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Presque Isle 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 Presque Isle County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Posen's 639 acreswhy one lot differs from the next →
- Which side of Posen you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 639 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 Posen-wide figureread your own land →
More in Michigan
Wider growing context
What grows across MichiganPosen sits outside our named growing regions, so Michigan as a whole is its closest context here.
Nearby growing guides