Grand Marais, Minnesota, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit cabbage, cranberry, turkish rocket, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Grand Marais, 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 Grand Marais 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 Grand Marais — soil, climate, flood, and parcel records. How we handle your address.
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Grand Marais — the short answer
Grand Marais, Minnesota: USDA zone 4b, about 181 days between hard freezes, across 2K acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 2K 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 4b is Grand Marais's average, not your lot's — a low corner or a tree line moves it. Against Grand Marais's 181-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grand Marais
Each reading below is measured for Grand Marais itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrand Marais runs about 181 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
MeasuredGrand Marais sits in USDA hardiness zone 4b.
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 Grand Marais is in
Grand Marais sits in the Northern Lakes and Forests — EPA Level III, inside the wider Northern Forests. That is read at Grand Marais's own centroid rather than borrowed from Cook County.
What Grows in Grand Marais
Every plant below cleared Grand Marais's own zone 4b and its 181-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Grand Marais?
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 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Grand Marais
Closest first, within ~10 miles of Grand Marais. Listing isn't leaking, and distance isn't exposure.
- Cook County Recycling CenterUnderground Storage Tanks · 1100 ft
- COOK COUNTY NORTH SHORE HOSPITALBrownfields · 1200 ft
- Uscg Station North SuperiorUnderground Storage Tanks · 0.6 mi
- NORTH HOUSE FOLK SCHOOLBrownfields · 0.7 mi
- Qwest Communications/Century LinkUnderground Storage Tanks · 0.7 mi
- School Bus GarageUnderground Storage Tanks · 0.7 mi
- Main Street GiftsUnderground Storage Tanks · 0.7 mi
- Grand Marais Rec Area MarinaUnderground Storage Tanks · 0.7 mi
- NORTH SHORE PHARMACY LTDBrownfields · 0.7 mi
- Buck's HardwareUnderground Storage Tanks · 0.7 mi
- Former Schold & Lovaas Service StationUnderground Storage Tanks · 0.7 mi
- Mike's Holiday Stationstore #516Underground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grand Marais'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 Grand Marais.
Sources Checked
within ~10 miles of Grand Marais
Severity Distribution
within ~10 miles of Grand Marais
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 Grand Marais
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 Grand Marais average
Your land is one point inside Grand Marais
Everything above resolves to Grand Marais as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Grand Marais Average
Grand Marais Average
- ●USDA Zones 4b, averaged across Grand Marais
- ●One soil character for all of Grand Marais
- ●Frost dates read at Grand Marais's scale: Apr 28 to Oct 26
YOUR Parcel
- ✓Your exact zone, not Grand Marais's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grand Marais
Pull a site-specific report for your exact address in Grand Marais, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grand Marais averages can't show:
We read public map data around Grand Marais — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grand Marais average
How we know this about Grand Marais
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 Grand Marais’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 Grand Marais
When does frost risk typically end in Grand Marais?
The last hard freeze (28°F) in Grand Marais typically lands around Apr 28, 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 19.
When is the first frost in Grand Marais?
The first hard freeze (28°F) in Grand Marais typically arrives around Oct 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 12, so the watching starts about Sep 26 — about 181 days after the spring freeze cleared.
How long is the growing season in Grand Marais?
Measured between 28°F hard freezes, Grand Marais sees about 181 frost-free days — roughly Apr 28 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Oct 12, about 146 days.
Is the soil safe to grow vegetables in Grand Marais?
The federal record around Grand Marais is light — 43 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (21), the nearest Underground Storage Tanks record about 0.2 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Grand Marais?
From about Sep 26 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 Oct 26 (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 Oct 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Grand Marais's scale — its 4b band and its 181-day season. Your yard writes its own version of Grand Marais'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 Grand Marais’s own scale
6 of the readings below were taken at Grand Marais's own scale — its own ~181-day season between 28°F freezes, the 1,862 acres it covers and 43 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grand Marais's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Grand Marais's own 28°F hard-freeze dates, about Apr 28 and Oct 26 and the ~181-day span between themNOAA 1991–2020 Climate Normals
- 43 documented contamination sites on the federal record near Grand Marais, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Grand Marais's boundary and the 1,862 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~181-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grand Marais's own centroid, the Northern Lakes and ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Grand Marais's 1,862 acres read through its county's SSURGO summaryfrom Cook County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Cook County
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Cook County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grand Marais's 1,862 acreswhy one lot differs from the next →
- Which side of Grand Marais you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,862 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 Grand Marais-wide figureread your own land →
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