Caspian, Michigan, sits in USDA hardiness zone 4a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Growers here do well with cabbage, cranberry, cilantro, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Caspian, 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 Caspian 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 Caspian — soil, climate, flood, and parcel records. How we handle your address.
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Caspian — the short answer
Caspian, Michigan: USDA zone 4a, about 124 days between hard freezes, across 913 acres of city.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~124
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 913 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 Caspian's average, not your lot's — a low corner or a tree line moves it. Against Caspian's 124-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Caspian
Each reading below is measured for Caspian itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCaspian runs about 124 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredCaspian 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 Caspian is in
Caspian sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Caspian's own centroid rather than borrowed from Iron County.
What Grows in Caspian
Every plant below cleared Caspian's own zone 4a and its 124-day season. Each card opens that plant's Michigan profile. How we score.
Is it too late to plant in Caspian?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 24 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 25 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What's on the federal record near Caspian
Closest first, within ~10 miles of Caspian. Listing isn't leaking, and distance isn't exposure.
- CITY OF CASPIANBrownfields · 450 ft
- City Of CaspianUnderground Storage Tanks · 450 ft
- Northland Super Service IncUnderground Storage Tanks · 1100 ft
- RODGERS/NELSON INCBrownfields · 1200 ft
- Krist Food Mart # 28Underground Storage Tanks · 1300 ft
- Carlsons ServiceUnderground Storage Tanks · 2500 ft
- Dober ShopUnderground Storage Tanks · 0.6 mi
- WE ENERGIESBrownfields · 1.0 mi
- Krist Oil CoUnderground Storage Tanks · 1.0 mi
- CITY OF GAASTRABrownfields · 1.1 mi
- Krist Oil Co Aircraft HangerUnderground Storage Tanks · 1.1 mi
- Stambaugh AirportUnderground Storage Tanks · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Caspian'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 Caspian.
Total Sites
76
within ~10 miles of Caspian
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Caspian
Severity Distribution
within ~10 miles of Caspian
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Caspian
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 Caspian average
Your land is one point inside Caspian
Everything above resolves to Caspian as a whole — one PHZM band and one 28°F frost record, read across 913 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 Caspian Average
Caspian Average
- ●USDA Zones 4a, averaged across Caspian
- ●One soil character for all of Caspian
- ●Frost dates read at Caspian's scale: May 24 to Sep 25
YOUR Parcel
- ✓Your exact zone, not Caspian's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Caspian
Pull a site-specific report for your exact address in Caspian, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Caspian averages can't show:
We read public map data around Caspian — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Caspian average
How we know this about Caspian
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 Caspian’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 Caspian
When does frost risk typically end in Caspian?
The last hard freeze (28°F) in Caspian typically lands around May 24, 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 14.
When is the first frost in Caspian?
The first hard freeze (28°F) in Caspian typically arrives around Sep 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 11, so the watching starts about Aug 26 — about 124 days after the spring freeze cleared.
How long is the growing season in Caspian?
Measured between 28°F hard freezes, Caspian sees about 124 frost-free days — roughly May 24 through Sep 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 14 to Sep 11, about 89 days.
Is the soil safe to grow vegetables in Caspian?
The federal record around Caspian shows 76 documented sites, mostly Underground Storage Tanks entries (42), the nearest Brownfields record under a tenth of a mile 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 gardeners stretch the season in Caspian?
With about 124 frost-free days between hard freezes, Caspian rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 152 to 180 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 24 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Caspian's scale — its 4a band and its 124-day season. Your yard writes its own version of Caspian'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 Caspian’s own scale
6 of the readings below were taken at Caspian's own scale — its own ~124-day season between 28°F freezes, the 913 acres it covers and 76 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Caspian's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Caspian's own 28°F hard-freeze dates, about May 24 and Sep 25 and the ~124-day span between themNOAA 1991–2020 Climate Normals
- 76 documented contamination sites on the federal record near Caspian, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Caspian's boundary and the 913 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~124-day seasonGrowable Ground crop-matching engine
- The ecoregion at Caspian'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 Caspian's 913 acres read through its county's SSURGO summaryfrom Iron County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Iron 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 Iron County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Caspian's 913 acreswhy one lot differs from the next →
- Which side of Caspian you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 913 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Caspian-wide figureread your own land →
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