Allegan County, in Michigan, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, hazelnut, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Allegan County lies within the Southwest Michigan Wine Coast — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Allegan County holds more than one microclimate.
Soils and elevations shift across Allegan 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 Allegan County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Allegan County — the short answer
Allegan County, Michigan: USDA zone 7a, about 217 days between hard freezes, across 528K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 12
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 15
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~217
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 528K 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 7a is Allegan County's average, not your lot's — a low corner or a tree line moves it. Against Allegan County's 217-day season, see what your own ground reads.
Heat in Allegan County
Across a year, Allegan County accumulates about 2,523 growing degree days above 50°F, about 423 more than the middle Michigan county — ahead of 74 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 Allegan County
Across Allegan County, the ground is predominantly Alfisols, where Chelsea, Capac, and Blount are the most extensive named soil series. The soil is generally somewhat poorly drained with a sand surface. Topsoil pH runs about 5.5–6.5, moderately acidic. Rainfall drains through hydrologic group A soils.
Soil order
Alfisols
Drainage
Somewhat poorly drained
Prime farmland
8%
Hydric soils
21%
Soil still varies lot by lot — soil types explained.
How the ground varies across Allegan County
The USDA soil survey maps 29% of Allegan County as somewhat poorly drained — but another 68% drains differently: 27% excessively drained, 18% well drained.
Chelsea is the most extensive named soil at 10% of mapped acres, then Capac (8%) and Blount (5%).
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 Allegan County
Each reading below is measured for Allegan 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 Allegan County are somewhat poorly drained, in hydrologic group A — 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 Allegan County runs about pH 5.5–6.5, 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
MeasuredAllegan County runs about 217 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredAllegan County sits in USDA hardiness zone 7a.
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 Allegan County is in
Allegan 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 Allegan County
We scored all 1,086 plants against Allegan County's own USDA zone 7a and its own 217-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 Allegan County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 15 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Allegan County
Survey cells within 31 miles of Allegan County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 44 miles off. What to watch for.
- Japanese beetle9 documented records
- monarch butterfly31 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Allegan County
USGS estimates 107,683 lb of Glyphosate on Allegan County farmland in 2019, its largest by weight, ahead of Acetochlor (36,756 lb) and Atrazine (29,014 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 Allegan County — and how to grow with it.
We checked the federal record across Allegan County — 735 documented sites across 7 of the 9 source types we track.
The most significant on record: 10 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 Allegan 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 Allegan County
Closest first, across Allegan County. Listing isn't leaking, and distance isn't exposure.
- MI DEPT/TRANSPORTATIONBrownfields · 0.5 mi
- SAUGATUCK GAP FILLERBrownfields · 3.0 mi
- Casco Township HallUnderground Storage Tanks · 3.5 mi
- South Haven Conference CenterUnderground Storage Tanks · 4.4 mi
- MI DEPT/TRANSPORTATION BRIDGE (S03-03033)Brownfields · 4.6 mi
- Adkin Blue Ribbon Packing CoUnderground Storage Tanks · 4.7 mi
- 109th Avenue WarehouseUnderground Storage Tanks · 4.8 mi
- Leon Brush FarmUnderground Storage Tanks · 5.7 mi
- WOLVERINE PIPELINE COMPANYBrownfields · 6.8 mi
- CONSUMERS ENERGY COBrownfields · 7.0 mi
- Hartmanns Plantation IncUnderground Storage Tanks · 7.0 mi
- Glenn Mobil ServiceUnderground Storage Tanks · 7.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Allegan 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 Allegan County.
Sources Checked
across Allegan County
Severity Distribution
across Allegan County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Allegan County, two things run higher than the national average across Allegan County — Toxics Release Inventory (54 sites) and Superfund (10 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Allegan 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 Allegan County average
Your land is one point inside Allegan County
Everything above resolves to Allegan County as a whole — one PHZM band and one county frost record, read across 528K 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 Allegan County Average
Allegan County Average
- ●USDA Zones 7a, averaged across Allegan County
- ●One soil character for all of Allegan County
- ●Frost dates read at Allegan County's scale: Apr 12 to Nov 15
YOUR Parcel
- ✓Your exact zone, not Allegan County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Allegan County
Pull a site-specific report for your exact address in Allegan County, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Allegan County averages can't show:
We read public map data around Allegan County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Allegan County average
How we know this about Allegan 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 Allegan County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Allegan County
When does frost risk typically end in Allegan County?
The last hard freeze (28°F) in Allegan County typically lands around Apr 12, 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 3.
How long is the growing season in Allegan County?
Measured between 28°F hard freezes, Allegan County sees about 217 frost-free days — roughly Apr 12 through Nov 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 3 to Nov 1, about 182 days.
Is the soil safe to grow vegetables in Allegan County?
The federal record around Allegan County is a meaningful one — 735 documented sites, mostly Underground Storage Tanks entries (378), the nearest Brownfields 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 Allegan County's scale — its 7a band and its 217-day season. Your yard writes its own version of Allegan 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 Allegan County’s own scale
9 of the readings below were taken at Allegan County's own scale — its own ~217-day span between 28°F freezes, the 3 most extensive soil series mapped here and 735 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Allegan County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Allegan County's own 28°F hard-freeze dates and its ~217-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Allegan CountyUSDA NRCS SSURGO
- 735 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.5 miles outFederal environmental registers
- Allegan County's boundary and the 528,275 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~217-day seasonGrowable Ground crop-matching engine
- Allegan County sitting wholly inside the Southern Michigan/Northern Indiana Drift PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Allegan County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Allegan 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 Allegan County — the ~217 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 Allegan County's 528,275 acreswhy one lot differs from the next →
- Which of those 735 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 Allegan Countyread your own land →