Wells County, in North Dakota, sits in USDA hardiness zone 4a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
These conditions suit sunflower, potato, american elm, and rhubarb — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Wells County holds more than one microclimate.
Soils and elevations shift across Wells 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
4a
Last Hard Freeze (28°F)
Apr 26
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 17
County normal — light frosts arrive a few weeks earlier
County Area
813K acres
Hardiness Zone Range
Zone maps are averages across Wells County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Wells County
Across Wells County, the ground is predominantly Mollisols, where Heimdal, Emrick, and Williams are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 7.0–7.2, neutral. Rainfall drains through hydrologic group B soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
52%
Hydric soils
10%
Soil still varies lot by lot — soil types explained.
What Grows in Wells County
Plants matched to Wells County's USDA zones 4a — each links to its full growing profile.




Is it too late to plant in Wells 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 Mar 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.

Growing Challenges in North Dakota
What an experienced grower plans around here — each one has a move.

Extreme cold (-40F) and short growing season
Cold-proven varieties plus a high tunnel make North Dakota's short season dependable — northern growers' standard kit.

Persistent wind desiccates plants
A windbreak is the highest-return structure on the northern plains — even a snow fence changes what survives.

Low rainfall in western ND
Out west, drip irrigation and mulch decide the season — set the water system up front.
For cultivar selection, pest pressure, and planting-time guidance specific to North Dakota, the NDSU Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Wells County — and how to grow with it.
We checked the federal record across Wells County — 190 documented sites across 4 of the 9 source types we track.
The most significant on record: 1 brownfield site. Former commercial or industrial land where legacy contamination may persist.
The federal record across Wells 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.
Sources Checked
across Wells County
Severity Distribution
across Wells County
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Wells County, Nitrate runs higher than the national average — 150 sites nearby. 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 Wells 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
Wells County Average
- ●USDA Zones 4a
- ●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 Wells County
Pull a site-specific report for your exact address in Wells County, North Dakota — 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 Wells County, North Dakota
- USDA Hardiness Zones: 4a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Apr 26 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 17 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~174 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 813K 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 Wells 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 Wells County, North Dakota?
Wells County sits in USDA hardiness zone 4a, 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 Wells 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 Mar 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
When does frost risk typically end in Wells County?
The last hard freeze (28°F) in Wells County typically lands around Apr 26, 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 Wells County?
Measured between 28°F hard freezes, Wells County sees about 174 frost-free days — roughly Apr 26 through Oct 17, 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 Wells County?
Wells County's zone 4a supports a wide range — strong performers include Sunflower, Potato, American Elm, and Rhubarb. 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 Wells County, really?
Officially, Wells County sits in USDA zone 4a (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 Wells County?
The federal record around Wells County shows 190 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 Wells County — what should I know before planting?
Start with three facts. Wells County sits in USDA zone 4a, which sets what survives winter; the last 28°F hard freeze typically clears around Apr 26, with about 174 frost-free days to work with (NOAA 1991–2020 climate normals); and 190 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 Wells 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 North Dakota's frost window, season length, and soil profile against the plant's real requirements.
