Algonac, Michigan, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Algonac, 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 Algonac 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 Algonac — soil, climate, flood, and parcel records. How we handle your address.
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Algonac — the short answer
Algonac, Michigan: USDA zone 6b, about 206 days between hard freezes, across 908 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 908 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 6b is Algonac's average, not your lot's — a low corner or a tree line moves it. Against Algonac's 206-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Algonac
Each reading below is measured for Algonac itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAlgonac runs about 206 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
MeasuredAlgonac sits in USDA hardiness zone 6b.
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 Algonac is in
Algonac sits in the Huron/Erie Lake Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Algonac's own centroid rather than borrowed from St. Clair County.
What Grows in Algonac
Every plant below cleared Algonac's own zone 6b and its 206-day season. Each card opens that plant's Michigan profile. How we score.
Is it too late to plant in Algonac?
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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 7 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Algonac
Survey cells within 31 miles of Algonac checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 39 miles off. What to watch for.
What's on the federal record near Algonac
Closest first, within ~10 miles of Algonac. Listing isn't leaking, and distance isn't exposure.
- Gilbert Funeral Home IncUnderground Storage Tanks · 1000 ft
- El Algonanin PlaceUnderground Storage Tanks · 1200 ft
- SunocoUnderground Storage Tanks · 1200 ft
- Former Gas StationUnderground Storage Tanks · 1400 ft
- City Of AlgonacUnderground Storage Tanks · 1400 ft
- (former) Kilets Gasoline StationUnderground Storage Tanks · 1400 ft
- Former Gasoline StationUnderground Storage Tanks · 2000 ft
- (former) Hemengers Gas StationUnderground Storage Tanks · 2100 ft
- Archie W BedellUnderground Storage Tanks · 2600 ft
- AUTO CRAFTBrownfields · 2600 ft
- WEST MARINE PRODUCTS INCBrownfields · 0.5 mi
- FAMILY DOLLAR STORESBrownfields · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Algonac'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 Algonac.
Total Sites
164
within ~10 miles of Algonac
Risk Level
Moderate
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Algonac
Severity Distribution
within ~10 miles of Algonac
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Algonac, two things run higher than the national average within ~10 miles of Algonac — PFAS (4 sites) and Underground Storage Tanks (110 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Algonac
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 Algonac average
Your land is one point inside Algonac
Everything above resolves to Algonac as a whole — one PHZM band and one 28°F frost record, read across 908 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 Algonac Average
Algonac Average
- ●USDA Zones 6b, averaged across Algonac
- ●One soil character for all of Algonac
- ●Frost dates read at Algonac's scale: Apr 15 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Algonac's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Algonac
Pull a site-specific report for your exact address in Algonac, Michigan — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Algonac averages can't show:
We read public map data around Algonac — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Algonac average
How we know this about Algonac
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 Algonac’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 Algonac
When does frost risk typically end in Algonac?
The last hard freeze (28°F) in Algonac typically lands around Apr 15, 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 6.
When is the first frost in Algonac?
The first hard freeze (28°F) in Algonac typically arrives around Nov 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 24, so the watching starts about Oct 8 — about 206 days after the spring freeze cleared.
How long is the growing season in Algonac?
Measured between 28°F hard freezes, Algonac sees about 206 frost-free days — roughly Apr 15 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 24, about 171 days.
Is the soil safe to grow vegetables in Algonac?
The federal record around Algonac shows 164 documented sites, mostly Underground Storage Tanks entries (110), the nearest Underground Storage Tanks record about 0.2 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Algonac?
From about Oct 8 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 Nov 7 (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 Nov 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Algonac's scale — its 6b band and its 206-day season. Your yard writes its own version of Algonac'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 Algonac’s own scale
7 of the readings below were taken at Algonac's own scale — its own ~206-day season between 28°F freezes, the 908 acres it covers and 164 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Algonac's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Algonac's own 28°F hard-freeze dates, about Apr 15 and Nov 7 and the ~206-day span between themNOAA 1991–2020 Climate Normals
- 164 documented contamination sites on the federal record near Algonac, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Algonac's boundary and the 908 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~206-day seasonGrowable Ground crop-matching engine
- The ecoregion at Algonac's own centroid, the Huron/Erie Lake PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Algonac 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 Algonac's 908 acres read through its county's SSURGO summaryfrom St. Clair County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom St. Clair 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 St. Clair County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Algonac's 908 acreswhy one lot differs from the next →
- Which side of Algonac you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 908 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Algonac-wide figureread your own land →
More in Michigan
Wider growing context
What grows across MichiganAlgonac sits outside our named growing regions, so Michigan as a whole is its closest context here.
Nearby growing guides