Sibley County, in Minnesota, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Sibley County holds more than one microclimate.
Soils and elevations shift across Sibley 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 Sibley County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Sibley County — the short answer
Sibley County, Minnesota: USDA zone 4b, about 187 days between hard freezes, across 377K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~187
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 377K 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 4b is Sibley County's average, not your lot's — a low corner or a tree line moves it. Against Sibley County's 187-day season, see what your own ground reads.
Heat in Sibley County
Across a year, Sibley County accumulates about 2,421 growing degree days above 50°F, about 156 more than the middle Minnesota county — ahead of 74 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 Sibley County
Across Sibley County, the ground is predominantly Mollisols, where Canisteo, Nicollet, and Okoboji are the most extensive named soil series. The soil is generally poorly drained with a clay loam surface. Topsoil pH runs about 6.2–7.5, neutral. Rainfall drains through hydrologic group C/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
28%
Hydric soils
63%
Soil still varies lot by lot — soil types explained.
How the ground varies across Sibley County
The USDA soil survey maps 47% of Sibley County as poorly drained — but another 51% drains differently: 17% somewhat poorly drained, 15% very poorly drained.
Canisteo is the most extensive named soil at 19% of mapped acres, then Nicollet (9%) and Okoboji (9%).
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 Sibley County
Each reading below is measured for Sibley 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 Sibley 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 Sibley County runs about pH 6.2–7.5, 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
MeasuredSibley County runs about 187 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
MeasuredSibley County 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 Sibley County is in
Sibley County spans 2 EPA Level III ecoregions — Western Corn Belt Plains (77%) and North Central Hardwood Forests (23%). 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 Sibley County
We scored all 1,086 plants against Sibley County's own USDA zone 4b and its own 187-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 Sibley County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 Oct 19 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What gets applied to farmland in Sibley County
USGS estimates 212,107 lb of Glyphosate on Sibley County farmland in 2019, its largest by weight, ahead of Acetochlor (153,234 lb) and Metolachlor & Metolachlor-s (27,733 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 Sibley County — and how to grow with it.
We checked the federal record across Sibley County — 360 documented sites across 6 of the 9 source types we track.
The most significant on record: 6 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Sibley 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 Sibley County
Closest first, across Sibley County. Listing isn't leaking, and distance isn't exposure.
- RIDGEVIEW GAYLORD CLINICBrownfields · 1.3 mi
- OAK TERRACE HEALTH CARE CENTERBrownfields · 1.3 mi
- OAK TERRACE HEALTH CENTERBrownfields · 1.3 mi
- ISD 231 SIBLEY EAST PUBLIC SCBrownfields · 1.4 mi
- Gaylord Community School Bus GarageUnderground Storage Tanks · 1.4 mi
- Brian's Quick LubeUnderground Storage Tanks · 1.4 mi
- Caseys General Stores #1646Underground Storage Tanks · 1.4 mi
- Former Tabbert OilUnderground Storage Tanks · 1.4 mi
- Independent Fertilizer Sales IncUnderground Storage Tanks · 1.4 mi
- Muck Keith/old StationUnderground Storage Tanks · 1.4 mi
- MG Waldbaum CoUnderground Storage Tanks · 1.4 mi
- HIghway 19 Scale and FuelUnderground Storage Tanks · 1.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sibley 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 Sibley County.
Total Sites
360
across Sibley County
Risk Level
Elevated
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
across Sibley County
Severity Distribution
across Sibley County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sibley County, two things run higher than the national average across Sibley County — CAFO (13 sites) and Nitrate (212 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Sibley 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 Sibley County average
Your land is one point inside Sibley County
Everything above resolves to Sibley County as a whole — one PHZM band and one county frost record, read across 377K 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 Sibley County Average
Sibley County Average
- ●USDA Zones 4b, averaged across Sibley County
- ●One soil character for all of Sibley County
- ●Frost dates read at Sibley County's scale: Apr 15 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Sibley County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Sibley County
Pull a site-specific report for your exact address in Sibley County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sibley County averages can't show:
We read public map data around Sibley County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sibley County average
How we know this about Sibley 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 Sibley County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Sibley County
When does frost risk typically end in Sibley County?
The last hard freeze (28°F) in Sibley County 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.
How long is the growing season in Sibley County?
Measured between 28°F hard freezes, Sibley County sees about 187 frost-free days — roughly Apr 15 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 5, about 152 days.
Is the soil safe to grow vegetables in Sibley County?
The federal record around Sibley County is a meaningful one — 360 documented sites, mostly Nitrate entries (212), the nearest Brownfields record about 1.3 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.
Everything above is measured at Sibley County's scale — its 4b band and its 187-day season. Your yard writes its own version of Sibley 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 Sibley County’s own scale
8 of the readings below were taken at Sibley County's own scale — its own ~187-day span between 28°F freezes, the 3 most extensive soil series mapped here and 360 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Sibley County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Sibley County's own 28°F hard-freeze dates and its ~187-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Sibley CountyUSDA NRCS SSURGO
- 360 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 1.3 miles outFederal environmental registers
- Sibley County's boundary and the 376,938 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~187-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Sibley County spans, Western Corn Belt Plains the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Sibley 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 Sibley County — the ~187 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 Sibley County's 376,938 acreswhy one lot differs from the next →
- Which of those 360 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 Sibley Countyread your own land →