St. Joseph County, in Michigan, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
St. Joseph County holds more than one microclimate.
Soils and elevations shift across St. Joseph 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 St. Joseph County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
St. Joseph County — the short answer
St. Joseph County, Michigan: USDA zone 6a, about 194 days between hard freezes, across 320K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~194
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 320K 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 St. Joseph County's average, not your lot's — a low corner or a tree line moves it. Against St. Joseph County's 194-day season, see what your own ground reads.
Heat in St. Joseph County
Across a year, St. Joseph County accumulates about 2,587 growing degree days above 50°F, about 487 more than the middle Michigan county — ahead of 77 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 St. Joseph County
Across St. Joseph County, the ground is predominantly Alfisols, where Oshtemo, Spinks, and Hillsdale are the most extensive named soil series. The soil is generally well drained with a sandy loam surface. Topsoil pH runs about 6.0–6.2, slightly acidic. Rainfall drains through hydrologic group A soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
46%
Hydric soils
16%
Soil still varies lot by lot — soil types explained.
How the ground varies across St. Joseph County
The USDA soil survey maps 69% of St. Joseph County as well drained — but another 25% drains differently: 9% very poorly drained, 6% poorly drained.
Oshtemo is the most extensive named soil at 33% of mapped acres, then Spinks (18%) and Hillsdale (13%).
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 St. Joseph County
Each reading below is measured for St. Joseph 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 St. Joseph County are well drained, in hydrologic group A — 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 St. Joseph County runs about pH 6.0–6.2, 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 16% of St. Joseph 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
MeasuredSt. Joseph County runs about 194 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 St. Joseph County is in
St. Joseph 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 St. Joseph County
We scored all 1,086 plants against St. Joseph County's own USDA zone 6a and its own 194-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 St. Joseph County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 28 — 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 St. Joseph County
Spotted lanternfly documented 8 miles from St. Joseph County, first recorded 2023. What to watch for.
- Japanese beetle1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in St. Joseph County
USGS estimates 175,271 lb of Glyphosate on St. Joseph County farmland in 2019, its largest by weight, ahead of Atrazine (75,264 lb) and Metolachlor & Metolachlor-s (61,176 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 St. Joseph County — and how to grow with it.
We checked the federal record across St. Joseph County — 481 documented sites across 5 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.
There's a meaningful federal record across St. Joseph County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near St. Joseph County
Closest first, across St. Joseph County. Listing isn't leaking, and distance isn't exposure.
- Centreville Public SchoolsUnderground Storage Tanks · 0.5 mi
- Centerville ShellUnderground Storage Tanks · 0.8 mi
- The Filling StationUnderground Storage Tanks · 0.8 mi
- Village Dpw GarageUnderground Storage Tanks · 0.9 mi
- Mill Race Dist Co IncUnderground Storage Tanks · 0.9 mi
- St. Joseph Co Sheriff DepartmenUnderground Storage Tanks · 0.9 mi
- Ross Sand & GravelUnderground Storage Tanks · 0.9 mi
- MEYER HYDRAULICSBrownfields · 1.1 mi
- VIKING RECREATIONAL VEHICLESBrownfields · 1.1 mi
- Viking Recreational Vehicles IncUnderground Storage Tanks · 1.1 mi
- FINNERMANS FARM AND GARDEN SVCBrownfields · 1.4 mi
- CFS IncUnderground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Joseph 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 St. Joseph County.
Sources Checked
across St. Joseph County
Severity Distribution
across St. Joseph County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Joseph County, Toxics Release Inventory runs higher than the national average — 33 sites across St. Joseph County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in St. Joseph 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 St. Joseph County average
Your land is one point inside St. Joseph County
Everything above resolves to St. Joseph County as a whole — one PHZM band and one county frost record, read across 320K 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 St. Joseph County Average
St. Joseph County Average
- ●USDA Zones 6a, averaged across St. Joseph County
- ●One soil character for all of St. Joseph County
- ●Frost dates read at St. Joseph County's scale: Apr 17 to Oct 28
YOUR Parcel
- ✓Your exact zone, not St. Joseph County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in St. Joseph County
Pull a site-specific report for your exact address in St. Joseph County, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Joseph County averages can't show:
We read public map data around St. Joseph County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Joseph County average
How we know this about St. Joseph 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 St. Joseph County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about St. Joseph County
When does frost risk typically end in St. Joseph County?
The last hard freeze (28°F) in St. Joseph County typically lands around Apr 17, 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 8.
How long is the growing season in St. Joseph County?
Measured between 28°F hard freezes, St. Joseph County sees about 194 frost-free days — roughly Apr 17 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 14, about 159 days.
Is the soil safe to grow vegetables in St. Joseph County?
The federal record around St. Joseph County is a meaningful one — 481 documented sites, mostly Underground Storage Tanks entries (271), the nearest Underground Storage Tanks record about 0.5 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
Everything above is measured at St. Joseph County's scale — its 6a band and its 194-day season. Your yard writes its own version of St. Joseph 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 St. Joseph County’s own scale
9 of the readings below were taken at St. Joseph County's own scale — its own ~194-day span between 28°F freezes, the 3 most extensive soil series mapped here and 481 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- St. Joseph County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- St. Joseph County's own 28°F hard-freeze dates and its ~194-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in St. Joseph CountyUSDA NRCS SSURGO
- 481 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.5 miles outFederal environmental registers
- St. Joseph County's boundary and the 320,409 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~194-day seasonGrowable Ground crop-matching engine
- St. Joseph County sitting wholly inside the Southern Michigan/Northern Indiana Drift PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in St. Joseph County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto St. Joseph 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 St. Joseph County — the ~194 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 St. Joseph County's 320,409 acreswhy one lot differs from the next →
- Which of those 481 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 St. Joseph Countyread your own land →