Gratiot County, in 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.
Crops well matched to these conditions include cabbage, blackberry, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Gratiot County holds more than one microclimate.
Soils and elevations shift across Gratiot County, so your frost dates and drainage aren't the county average. 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 Gratiot County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Gratiot County — the short answer
Gratiot County, Michigan: USDA zone 6a, about 179 days between hard freezes, across 364K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 25
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~179
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 364K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Gratiot County's average, not your lot's — a low corner or a tree line moves it. Against Gratiot County's 179-day season, see what your own ground reads.
Heat in Gratiot County
Across a year, Gratiot County accumulates about 2,301 growing degree days above 50°F, about 201 more than the middle Michigan county — ahead of 52 of Michigan’s 83 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Gratiot County
Across Gratiot County, the ground is predominantly Alfisols, where Parkhill, Capac, and Selfridge are the most extensive named soil series. The soil is generally poorly drained with a loam surface. Topsoil pH runs about 6.5–7.0, neutral. Rainfall drains through hydrologic group C/D soils.
Soil order
Alfisols
Drainage
Poorly drained
Prime farmland
13%
Hydric soils
48%
Soil still varies lot by lot — soil types explained.
How the ground varies across Gratiot County
The USDA soil survey maps 44% of Gratiot County as poorly drained — but another 56% drains differently: 38% somewhat poorly drained, 6% moderately well drained.
Parkhill is the most extensive named soil at 17% of mapped acres, then Capac (10%) and Selfridge (7%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Gratiot County
Each reading below is measured for Gratiot County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Gratiot County are poorly drained, in hydrologic group C/D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Gratiot County runs about pH 6.5–7.0, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredGratiot County runs about 179 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
MeasuredGratiot County 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 Gratiot County is in
Gratiot County spans 2 EPA Level III ecoregions — Southern Michigan/Northern Indiana Drift Plains (81%) and Huron/Erie Lake Plains (19%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Gratiot County
We scored all 1,086 plants against Gratiot County's own USDA zone 6a and its own 179-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Michigan profile.
Is it too late to plant in Gratiot County?
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 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 21 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Gratiot County
Survey cells within 31 miles of Gratiot County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 81 miles off. What to watch for.
- monarch butterfly2 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Gratiot County
USGS estimates 127,721 lb of Glyphosate on Gratiot County farmland in 2019, its largest by weight, ahead of Atrazine (27,772 lb) and Metolachlor & Metolachlor-s (27,498 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Gratiot County — and how to grow with it.
We checked the federal record across Gratiot County — 359 documented sites across 6 of the 9 source types we track.
The most significant on record: 7 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Gratiot County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Gratiot County
Closest first, across Gratiot County. Listing isn't leaking, and distance isn't exposure.
- E & S GraphicsUnderground Storage Tanks · 250 ft
- Claggs Super ServiceUnderground Storage Tanks · 250 ft
- GRATIOT COUNTY COURT HOUSEBrownfields · 250 ft
- Beacon & Bridge Market #17Underground Storage Tanks · 300 ft
- Macdonald Dance StudioUnderground Storage Tanks · 300 ft
- Hub Oil Property 93-2Underground Storage Tanks · 400 ft
- Gerald Zeilinger Property 91-24Underground Storage Tanks · 400 ft
- Clares TotalUnderground Storage Tanks · 400 ft
- SHAW'S BODY SHOP LLCBrownfields · 400 ft
- APC STORES INCBrownfields · 900 ft
- SCHRADER ENVIRONMENTAL SERVICES INCBrownfields · 1000 ft
- Package Building SupplyUnderground Storage Tanks · 1300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Gratiot County'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 Gratiot County.
Sources Checked
across Gratiot County
Severity Distribution
across Gratiot County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Gratiot County, two things run higher than the national average across Gratiot County — 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 Gratiot County
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 Gratiot County average
Your land is one point inside Gratiot County
Everything above resolves to Gratiot County as a whole — one PHZM band and one county frost record, read across 364K 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 county 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 county average.
Your Lot vs the Gratiot County Average
Gratiot County Average
- ●USDA Zones 6a, averaged across Gratiot County
- ●One soil character for all of Gratiot County
- ●Frost dates read at Gratiot County's scale: Apr 25 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Gratiot County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Gratiot County
Pull a site-specific report for your exact address in Gratiot County, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Gratiot County averages can't show:
We read public map data around Gratiot County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Gratiot County average
How we know this about Gratiot County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Gratiot County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Gratiot County
When does frost risk typically end in Gratiot County?
The last hard freeze (28°F) in Gratiot County typically lands around Apr 25, 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 16.
How long is the growing season in Gratiot County?
Measured between 28°F hard freezes, Gratiot County sees about 179 frost-free days — roughly Apr 25 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 16 to Oct 7, about 144 days.
Is the soil safe to grow vegetables in Gratiot County?
The federal record around Gratiot County runs heavier than most — 359 documented sites, mostly Underground Storage Tanks entries (216), the nearest Underground Storage Tanks record under a tenth of a mile 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.
Everything above is measured at Gratiot County's scale — its 6a band and its 179-day season. Your yard writes its own version of Gratiot County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Michigan's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Gratiot County’s own scale
9 of the readings below were taken at Gratiot County's own scale — its own ~179-day span between 28°F freezes, the 3 most extensive soil series mapped here and 359 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Gratiot County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Gratiot County's own 28°F hard-freeze dates and its ~179-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Gratiot CountyUSDA NRCS SSURGO
- 359 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record under a tenth of a mile outFederal environmental registers
- Gratiot County's boundary and the 363,764 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~179-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Gratiot County spans, Southern Michigan/Northern Indiana Drift Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Gratiot County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Gratiot County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Michigan grower plans around — written at state scale, so they stay on the state guidefrom Michigan
What this page can’t tell you
- How the season shifts across Gratiot County — the ~179 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Gratiot County's 363,764 acreswhy one lot differs from the next →
- Which of those 359 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Gratiot Countyread your own land →