Roseau County, in Minnesota, sits in USDA hardiness zone 3b — a zone band wide enough that plant choice, not possibility, is the interesting question.
These conditions suit cabbage, cranberry, epazote, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Roseau 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
Roseau County holds more than one microclimate.
Soils and elevations shift across Roseau 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 Roseau County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Roseau County — the short answer
Roseau County, Minnesota: USDA zone 3b, about 149 days between hard freezes, across 1.1M acres.
- USDA zone
- 3b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 8
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~149
- 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 Roseau County's average, not your lot's — a low corner or a tree line moves it. Against Roseau County's 149-day season, see what your own ground reads.
Heat in Roseau County
Across a year, Roseau County accumulates about 1,596 growing degree days above 50°F, about 669 fewer than the middle Minnesota county — ahead of 6 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 Roseau County
Across Roseau County, the ground is predominantly Mollisols, where Percy, Seelyeville, and Redby are the most extensive named soil series. The soil is generally poorly drained with a loam surface. Topsoil pH runs about 6.7–7.5, neutral. Rainfall drains through hydrologic group C/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
3%
Hydric soils
78%
Soil still varies lot by lot — soil types explained.
How the ground varies across Roseau County
The USDA soil survey maps 50% of Roseau County as poorly drained — but another 50% drains differently: 29% very poorly drained, 14% moderately well drained.
Percy is the most extensive named soil at 21% of mapped acres, then Seelyeville (4%) and Redby (4%).
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 Roseau County
Each reading below is measured for Roseau 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 Roseau County are poorly drained, in hydrologic group C/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 Roseau County runs about pH 6.7–7.5, 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
MeasuredRoseau County runs about 149 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRoseau 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 Roseau County is in
Roseau County spans 2 EPA Level III ecoregions — Northern Minnesota Wetlands (58%) and Lake Agassiz Plain (42%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Roseau County
We scored all 1,086 plants against Roseau County's own USDA zone 3b and its own 149-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 Roseau County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 4 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
Documented around Roseau County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Roseau County
USGS estimates 163,917 lb of Glyphosate on Roseau County farmland in 2019, its largest by weight, ahead of Bromoxynil (20,151 lb) and Dicamba (18,829 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 Roseau County — and how to grow with it.
We checked the federal record across Roseau County — 242 documented sites across 5 of the 9 source types we track.
The most significant on record: 5 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Roseau 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 Roseau County
Closest first, across Roseau County. Listing isn't leaking, and distance isn't exposure.
- 161N40W12CAA 01 A EricksonNitrate · 3.3 mi
- 161N41W36BCC 01 A MonsrudNitrate · 4.2 mi
- 160N40W09AAB 02Nitrate · 4.3 mi
- 438024Nitrate · 5.2 mi
- Johnson Oil Bulk Plant IIUnderground Storage Tanks · 5.7 mi
- Progressive Tool & EngineeringUnderground Storage Tanks · 5.9 mi
- Roseau River Wma HeadquartersUnderground Storage Tanks · 5.9 mi
- Former Roseau County Extension OfficeUnderground Storage Tanks · 5.9 mi
- Polaris Industries Inc - RoseauUnderground Storage Tanks · 5.9 mi
- Roseau Diesel Service IncUnderground Storage Tanks · 5.9 mi
- Land O Lakes - RoseauUnderground Storage Tanks · 5.9 mi
- D & E SportsUnderground Storage Tanks · 5.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Roseau 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 Roseau County.
Total Sites
242
across Roseau County
Risk Level
Elevated
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
across Roseau County
Severity Distribution
across Roseau County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Roseau County, Nitrate runs higher than the national average — 104 sites across Roseau 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 Roseau 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 Roseau County average
Your land is one point inside Roseau County
Everything above resolves to Roseau 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 Roseau County Average
Roseau County Average
- ●USDA Zones 3b, averaged across Roseau County
- ●One soil character for all of Roseau County
- ●Frost dates read at Roseau County's scale: May 8 to Oct 4
YOUR Parcel
- ✓Your exact zone, not Roseau County's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Roseau County
Pull a site-specific report for your exact address in Roseau County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Roseau County averages can't show:
We read public map data around Roseau County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Roseau County average
How we know this about Roseau 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 Roseau County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Roseau County
When does frost risk typically end in Roseau County?
The last hard freeze (28°F) in Roseau County typically lands around May 8, 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 29.
How long is the growing season in Roseau County?
Measured between 28°F hard freezes, Roseau County sees about 149 frost-free days — roughly May 8 through Oct 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 29 to Sep 20, about 114 days.
Is the soil safe to grow vegetables in Roseau County?
The federal record around Roseau County is a meaningful one — 242 documented sites, mostly Nitrate entries (104), the nearest Nitrate record about 3.3 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.
How do gardeners stretch the season in Roseau County?
With about 149 frost-free days between hard freezes, Roseau County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 177 to 205 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 8 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Roseau County's scale — its 3b band and its 149-day season. Your yard writes its own version of Roseau 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 Roseau County’s own scale
9 of the readings below were taken at Roseau County's own scale — its own ~149-day span between 28°F freezes, the 3 most extensive soil series mapped here and 242 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Roseau County's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Roseau County's own 28°F hard-freeze dates and its ~149-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Roseau CountyUSDA NRCS SSURGO
- 242 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 3.3 miles outFederal environmental registers
- Roseau County's boundary and the 1,069,912 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~149-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Roseau County spans, Northern Minnesota Wetlands the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Roseau County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Roseau 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 Roseau County — the ~149 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 Roseau County's 1,069,912 acreswhy one lot differs from the next →
- Which of those 242 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 Roseau Countyread your own land →