Alma, Michigan, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Alma, 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 Alma 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 Alma — soil, climate, flood, and parcel records. How we handle your address.
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Alma — the short answer
Alma, Michigan: USDA zone 6a, about 182 days between hard freezes, across 4K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~182
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 4K 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 6a is Alma's average, not your lot's — a low corner or a tree line moves it. Against Alma's 182-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Alma
Each reading below is measured for Alma itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAlma 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
MeasuredAlma sits in USDA hardiness zone 6a.
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 Alma is in
Alma sits in the Southern Michigan/Northern Indiana Drift Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Alma's own centroid rather than borrowed from Gratiot County.
What Grows in Alma
Every plant below cleared Alma's own zone 6a and its 182-day season. Each card opens that plant's Michigan profile. How we score.
Is it too late to plant in Alma?
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 Mar 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 24 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 23 — 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.
Documented around Alma
Survey cells within 31 miles of Alma checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 87 miles off. What to watch for.
What's on the federal record near Alma
Closest first, within ~10 miles of Alma. Listing isn't leaking, and distance isn't exposure.
- Beacon & Bridge Market #31Underground Storage Tanks · 750 ft
- Gratiot Investments IncUnderground Storage Tanks · 850 ft
- GTE NORTH ALMA COBrownfields · 900 ft
- QUALITY PRINTINGBrownfields · 1000 ft
- CONSUMERS ENERGY COBrownfields · 1200 ft
- Admiral Petroleum Co #18Underground Storage Tanks · 1200 ft
- D & S Auto TrimUnderground Storage Tanks · 1300 ft
- D.w. Brice Construction Co IncUnderground Storage Tanks · 1500 ft
- ALMA PRODUCTS I INCORPORATEDBrownfields · 1600 ft
- Court Street PlantUnderground Storage Tanks · 1600 ft
- ASAP SALES & SERVICEBrownfields · 1700 ft
- Playbouy Pontoon ManufacturingUnderground Storage Tanks · 1800 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Alma'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 Alma.
Sources Checked
within ~10 miles of Alma
Severity Distribution
within ~10 miles of Alma
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Alma, two things run higher than the national average within ~10 miles of Alma — Superfund (7 sites) and PFAS (3 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Alma
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 Alma average
Your land is one point inside Alma
Everything above resolves to Alma as a whole — one PHZM band and one 28°F frost record, read across 4K 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 Alma Average
Alma Average
- ●USDA Zones 6a, averaged across Alma
- ●One soil character for all of Alma
- ●Frost dates read at Alma's scale: Apr 24 to Oct 23
YOUR Parcel
- ✓Your exact zone, not Alma's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Alma
Pull a site-specific report for your exact address in Alma, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Alma averages can't show:
We read public map data around Alma — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alma average
How we know this about Alma
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 Alma’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 Alma
When does frost risk typically end in Alma?
The last hard freeze (28°F) in Alma typically lands around Apr 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 May 15.
When is the first frost in Alma?
The first hard freeze (28°F) in Alma typically arrives around Oct 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 9, so the watching starts about Sep 23 — about 182 days after the spring freeze cleared.
How long is the growing season in Alma?
Measured between 28°F hard freezes, Alma sees about 182 frost-free days — roughly Apr 24 through Oct 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 15 to Oct 9, about 147 days.
Is the soil safe to grow vegetables in Alma?
The federal record around Alma runs heavier than most — 310 documented sites, mostly Underground Storage Tanks entries (177), the nearest Underground Storage Tanks record about 0.1 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Alma?
From about Sep 23 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 23 (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 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Alma's scale — its 6a band and its 182-day season. Your yard writes its own version of Alma'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 Alma’s own scale
7 of the readings below were taken at Alma's own scale — its own ~182-day season between 28°F freezes, the 3,826 acres it covers and 310 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Alma's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Alma's own 28°F hard-freeze dates, about Apr 24 and Oct 23 and the ~182-day span between themNOAA 1991–2020 Climate Normals
- 310 documented contamination sites on the federal record near Alma, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Alma's boundary and the 3,826 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~182-day seasonGrowable Ground crop-matching engine
- The ecoregion at Alma's own centroid, the Southern Michigan/Northern Indiana Drift PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Alma checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Alma's 3,826 acres read through its county's SSURGO summaryfrom Gratiot County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Gratiot 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 Gratiot County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Alma's 3,826 acreswhy one lot differs from the next →
- Which side of Alma you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,826 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Alma-wide figureread your own land →
More in Michigan
Wider growing context
What grows across MichiganAlma sits outside our named growing regions, so Michigan as a whole is its closest context here.
Nearby growing guides