Pennington County, in Minnesota, sits in USDA hardiness zone 3b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Expect honeycrisp apple, wild rice, tomato, and red pine 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
Pennington County holds more than one microclimate.
Soils and elevations shift across Pennington County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
3b
Last Hard Freeze (28°F)
Apr 23
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 20
County normal — light frosts arrive a few weeks earlier
County Area
395K acres
Hardiness Zone Range
Zone maps are averages across Pennington County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Pennington County
Across Pennington County, the ground is predominantly Mollisols, where Smiley, Kratka, and Reiner are the most extensive named soil series. The soil is generally poorly drained with a fine sandy loam surface. Topsoil pH runs about 7.0–7.5, neutral. Rainfall drains through hydrologic group B/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
19%
Hydric soils
72%
Soil still varies lot by lot — soil types explained.
What Grows in Pennington County
Plants matched to Pennington County's USDA zones 3b — each links to its full growing profile.
Is it too late to plant in Pennington County?
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 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — 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.
Growing Challenges in Minnesota
What an experienced grower plans around here — each one has a move.
Extreme cold (zone 3a: -40F) limits many species
Plant to zone 3 realities and the garden thrives — the hardy-plant palette here is deeper than most catalogs suggest.
Short growing season (100-140 frost-free days)
Start transplants indoors and add a cold frame — the standard Minnesota moves that stretch a short season into a full one.
Heavy clay soils in the Red River Valley
Valley clay grows world-class crops once drainage is handled — raised beds do it instantly, compost does it permanently.
For cultivar selection, pest pressure, and planting-time guidance specific to Minnesota, the University of Minnesota Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Pennington County — and how to grow with it.
We checked the federal record across Pennington County — 164 documented sites across 5 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.
The federal record across Pennington County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Total Sites
164
across Pennington County
Risk Level
Moderate
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
across Pennington County
Severity Distribution
across Pennington County
Highest-Severity Sites
Know Before You Grow
- •Raised beds with imported soil can reduce exposure risk near brownfield sites.
- •Underground tanks can leak petroleum products. Soil testing near former gas stations is recommended.
- •Test well water for nitrates if you rely on a private well. Levels above 10 mg/L require treatment.
Check your specific parcel in Pennington County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Pennington County Average
- ●USDA Zones 3b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Pennington County
Pull a site-specific report for your exact address in Pennington County, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Pennington County, Minnesota
- USDA Hardiness Zones: 3b (USDA PHZM 2023)
- Last Hard Freeze (28°F): Apr 23 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 20 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~180 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 395K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Pennington County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Pennington County, Minnesota?
Pennington County sits in USDA hardiness zone 3b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Pennington County?
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 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — 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.
When does frost risk typically end in Pennington County?
The last hard freeze (28°F) in Pennington County typically lands around Apr 23, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Pennington County?
Measured between 28°F hard freezes, Pennington County sees about 180 frost-free days — roughly Apr 23 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Pennington County?
Pennington County's zone 3b supports a wide range — strong performers include Honeycrisp Apple, Wild Rice, Tomato, and Red Pine. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Pennington County, really?
Officially, Pennington County sits in USDA zone 3b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Pennington County?
The federal record around Pennington County shows 164 documented sites — 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.
Just moved to Pennington County — what should I know before planting?
Start with three facts. Pennington County sits in USDA zone 3b, which sets what survives winter; the last 28°F hard freeze typically clears around Apr 23, with about 180 frost-free days to work with (NOAA 1991–2020 climate normals); and 164 documented sites sit on the federal record — a typical footprint for a growing area, worth a look on the contamination map before food beds. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Pennington County average. Your yard writes its own version — 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.