Marshall County, in Minnesota, sits in USDA hardiness zone 3b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, cranberry, turkish rocket, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Marshall County lies within the Red River Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Marshall County holds more than one microclimate.
Soils and elevations shift across Marshall 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 Marshall County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Marshall County — the short answer
Marshall County, Minnesota: USDA zone 3b, about 156 days between hard freezes, across 1.1M acres.
- USDA zone
- 3b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 3
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 6
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~156
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.1M 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 3b is Marshall County's average, not your lot's — a low corner or a tree line moves it. Against Marshall County's 156-day season, see what your own ground reads.
Heat in Marshall County
Across a year, Marshall County accumulates about 1,745 growing degree days above 50°F, about 520 fewer than the middle Minnesota county — ahead of 12 of Minnesota’s 87 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 Marshall County
Across Marshall County, the ground is predominantly Mollisols, where Fargo, Smiley, and Roliss are the most extensive named soil series. The soil is generally poorly drained with a loam surface. Topsoil pH runs about 7.2–7.9, slightly alkaline. Rainfall drains through hydrologic group B/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
12%
Hydric soils
74%
Soil still varies lot by lot — soil types explained.
How the ground varies across Marshall County
The USDA soil survey maps 56% of Marshall County as poorly drained — but another 43% drains differently: 15% very poorly drained, 14% somewhat poorly drained.
Fargo is the most extensive named soil at 10% of mapped acres, then Smiley (7%) and Roliss (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 Marshall County
Each reading below is measured for Marshall 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 Marshall County are poorly drained, in hydrologic group B/D — 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 Marshall County runs about pH 7.2–7.9, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredMarshall County runs about 156 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
MeasuredMarshall County sits in USDA hardiness zone 3b.
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 Marshall County is in
Marshall County sits in the Lake Agassiz Plain — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Marshall County
We scored all 1,086 plants against Marshall County's own USDA zone 3b and its own 156-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 Minnesota profile.
Is it too late to plant in Marshall 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 Apr 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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 Marshall County
- monarch butterfly3 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Marshall County
USGS estimates 367,040 lb of Glyphosate on Marshall County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (77,011 lb) and Metolachlor-s (68,369 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 Marshall County — and how to grow with it.
We checked the federal record across Marshall County — 216 documented sites across 5 of the 9 source types we track.
The most significant on record: 1 Toxics Release Inventory facility. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Marshall 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 Marshall County
Closest first, across Marshall County. Listing isn't leaking, and distance isn't exposure.
- New Bus GarageUnderground Storage Tanks · 1.2 mi
- ISD 441 NEWFOLDEN SCHOOL BUS GARAGEBrownfields · 1.2 mi
- ISD 441 MARSHALL COUNTY CENTRAL SCHOOLSBrownfields · 1.2 mi
- ISD 441 NEWFOLDEN ELEMENTARY SCHOOLBrownfields · 1.2 mi
- Old Bus GarageUnderground Storage Tanks · 1.3 mi
- NEWFOLDEN MACHINING COBrownfields · 1.4 mi
- SWAN OIL COBrownfields · 1.4 mi
- 156N44W05DDC 02 NewfoldenNitrate · 1.4 mi
- 156N44W08AAB 01 R ElsethNitrate · 1.4 mi
- NEWFOLDEN CITY OFBrownfields · 1.4 mi
- DAHL'S SERVICE & REPAIRBrownfields · 1.8 mi
- 156N45W09ABA 01 A OrdahlNitrate · 3.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Marshall 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 Marshall County.
Total Sites
216
across Marshall County
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
across Marshall County
Severity Distribution
across Marshall County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Marshall County, Nitrate runs higher than the national average — 116 sites across Marshall County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Marshall 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 Marshall County average
Your land is one point inside Marshall County
Everything above resolves to Marshall County as a whole — one PHZM band and one county frost record, read across 1.1M 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 Marshall County Average
Marshall County Average
- ●USDA Zones 3b, averaged across Marshall County
- ●One soil character for all of Marshall County
- ●Frost dates read at Marshall County's scale: May 3 to Oct 6
YOUR Parcel
- ✓Your exact zone, not Marshall County's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Marshall County
Pull a site-specific report for your exact address in Marshall County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Marshall County averages can't show:
We read public map data around Marshall County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Marshall County average
How we know this about Marshall 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 Marshall County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Marshall County
When does frost risk typically end in Marshall County?
The last hard freeze (28°F) in Marshall County typically lands around May 3, 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 24.
How long is the growing season in Marshall County?
Measured between 28°F hard freezes, Marshall County sees about 156 frost-free days — roughly May 3 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 24 to Sep 22, about 121 days.
Is the soil safe to grow vegetables in Marshall County?
The federal record around Marshall County is a meaningful one — 216 documented sites, mostly Nitrate entries (116), the nearest Underground Storage Tanks record about 1.2 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 Marshall County's scale — its 3b band and its 156-day season. Your yard writes its own version of Marshall 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 Minnesota's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Marshall County’s own scale
9 of the readings below were taken at Marshall County's own scale — its own ~156-day span between 28°F freezes, the 3 most extensive soil series mapped here and 216 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Marshall County's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Marshall County's own 28°F hard-freeze dates and its ~156-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Marshall CountyUSDA NRCS SSURGO
- 216 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.2 miles outFederal environmental registers
- Marshall County's boundary and the 1,136,037 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~156-day seasonGrowable Ground crop-matching engine
- Marshall County sitting wholly inside the Lake Agassiz PlainUS EPA Level III Ecoregions
- Open occurrence records documented in Marshall County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Marshall County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
What this page can’t tell you
- How the season shifts across Marshall County — the ~156 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 Marshall County's 1,136,037 acreswhy one lot differs from the next →
- Which of those 216 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 Marshall Countyread your own land →