Ionia County, in Michigan, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Reliable performers under these conditions include cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Ionia County holds more than one microclimate.
Soils and elevations shift across Ionia 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 Ionia County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Ionia County — the short answer
Ionia County, Michigan: USDA zone 6a, about 186 days between hard freezes, across 366K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 22
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~186
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 366K 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 Ionia County's average, not your lot's — a low corner or a tree line moves it. Against Ionia County's 186-day season, see what your own ground reads.
Heat in Ionia County
Across a year, Ionia County accumulates about 2,415 growing degree days above 50°F, about 315 more than the middle Michigan county — ahead of 61 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 Ionia County
Across Ionia County, the ground is predominantly Alfisols, where Capac, Celina, and Marlette are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.2–6.6, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
32%
Hydric soils
22%
Soil still varies lot by lot — soil types explained.
How the ground varies across Ionia County
The USDA soil survey maps 51% of Ionia County as well drained — but another 47% drains differently: 18% somewhat poorly drained, 16% poorly drained.
Capac is the most extensive named soil at 9% of mapped acres, then Celina (7%) and Marlette (6%).
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 Ionia County
Each reading below is measured for Ionia 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 Ionia County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Ionia County runs about pH 6.2–6.6, 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
Wet ground
MeasuredAbout 22% of Ionia County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredIonia County runs about 186 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
The kind of country Ionia County is in
Ionia County sits in the Southern Michigan/Northern Indiana Drift Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Ionia County
We scored all 1,086 plants against Ionia County's own USDA zone 6a and its own 186-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 Ionia County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — 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 Ionia County
Survey cells within 31 miles of Ionia County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 73 miles off. What to watch for.
- monarch butterfly65 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Ionia County
USGS estimates 140,758 lb of Glyphosate on Ionia County farmland in 2019, its largest by weight, ahead of Atrazine (51,554 lb) and Metolachlor & Metolachlor-s (31,223 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 Ionia County — and how to grow with it.
We checked the federal record across Ionia County — 415 documented sites across 7 of the 9 source types we track.
The most significant on record: 3 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Ionia 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 Ionia County
Closest first, across Ionia County. Listing isn't leaking, and distance isn't exposure.
- KMART CORPORATIONBrownfields · 350 ft
- SPECTRUM HEALTHBrownfields · 650 ft
- WALMART SUPERCENTERBrownfields · 700 ft
- MEIJER INCBrownfields · 700 ft
- Meijer #303Underground Storage Tanks · 850 ft
- PETCO #5839Brownfields · 1200 ft
- Former Ionia State Police PostUnderground Storage Tanks · 1200 ft
- LOWES HOME CENTERS INCBrownfields · 1200 ft
- Ionia County AirportUnderground Storage Tanks · 1300 ft
- IONIA DIALYSISBrownfields · 1400 ft
- TRACTOR SUPPLY COMPANYBrownfields · 1800 ft
- Ionia PlantUnderground Storage Tanks · 2300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Ionia 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 Ionia County.
Severity Distribution
across Ionia County
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 Ionia 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 Ionia County average
Your land is one point inside Ionia County
Everything above resolves to Ionia County as a whole — one PHZM band and one county frost record, read across 366K 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 Ionia County Average
Ionia County Average
- ●USDA Zones 6a, averaged across Ionia County
- ●One soil character for all of Ionia County
- ●Frost dates read at Ionia County's scale: Apr 22 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Ionia County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Ionia County
Pull a site-specific report for your exact address in Ionia County, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Ionia County averages can't show:
We read public map data around Ionia County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ionia County average
How we know this about Ionia 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 Ionia County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Ionia County
When does frost risk typically end in Ionia County?
The last hard freeze (28°F) in Ionia County typically lands around Apr 22, 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 13.
How long is the growing season in Ionia County?
Measured between 28°F hard freezes, Ionia County sees about 186 frost-free days — roughly Apr 22 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 13 to Oct 11, about 151 days.
Is the soil safe to grow vegetables in Ionia County?
The federal record around Ionia County runs heavier than most — 415 documented sites, mostly Underground Storage Tanks entries (232), the nearest Brownfields 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 Ionia County's scale — its 6a band and its 186-day season. Your yard writes its own version of Ionia 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 Ionia County’s own scale
9 of the readings below were taken at Ionia County's own scale — its own ~186-day span between 28°F freezes, the 3 most extensive soil series mapped here and 415 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Ionia County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Ionia County's own 28°F hard-freeze dates and its ~186-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Ionia CountyUSDA NRCS SSURGO
- 415 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record under a tenth of a mile outFederal environmental registers
- Ionia County's boundary and the 365,644 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~186-day seasonGrowable Ground crop-matching engine
- Ionia County sitting wholly inside the Southern Michigan/Northern Indiana Drift PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Ionia County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Ionia 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 Ionia County — the ~186 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 Ionia County's 365,644 acreswhy one lot differs from the next →
- Which of those 415 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 Ionia Countyread your own land →